Saturday, April 29, 2006

Attack of the blue foamy pterosaurs

It's amazing the things we'll do to avoid work. Here is me, today, with the foam tupuxuarid* skeleton that Mark and Graeme are making - so, if Mark and Graeme are making it, why the hell aren't they in the photo? Well, because this is my blog site and I'll show what the hell I like. But seriously, yet again the image is something I've ripped off from Mark's site (link below - do visit for general hilarity, some of it pterosaur related). I have a special fondness for Tupuxuara and its relatives, as will be demonstrated by future posts (and by Martill & Naish, in press.. but more about that when it's out).

* 'Tupuxuarid'? What the hell kind of name is that? Stay tuned.

Actually, I didn't just muck around today - I worked hard on my thesis of course. Putting the last touches to it now. Did the final runs of my theropod data matrices, and got excellent results that I'll talk about here in the near future. Mirischia and Proceratosaurus both tyrannosauroids? Jinfengopteryx a basal troodontid? Compsognathids a paraphyletic assemblage of basal coelurosaurs? Lourinhanosaurus not an allosauroid? And what of Eotyrannus? All will be revealed...

Much blue foam pterosaur goodness at...

Back to the thesis.

Wednesday, April 26, 2006

T2: Judgement Day...

.... and hedgehogs.

Just a reminder to those who follow my blog posts: April 30th is 'T2: Judgement Day', with the 'T' standing for 'Thesis' (and it's 'T2' because my MPhil dissertation, submitted in 1999, was 'T1'). So, very nearly there, and working very hard. I worked on Chapter 4 until 04-10 this morning, and will be doing the same tonight/tomorrow morning (albeit on different chapters of course). Trying very hard to resist the distraction caused by the hedgehog Erinaceus europaeus that has moved into our garden, and whom I caught rummaging through our rubbish Monday night (see photo). I never realised hedgehogs smelt so bad (the individuals I've handled previously didn't, maybe it's just this one). Anyway, back to work.

Oh yeah, when the thesis is finished there will be some kind of big night out. Do come along.

And for the latest news on Tetrapod Zoology do go here.

Sunday, April 23, 2006

On those pesky prehistoric survivors: a call to arms

With a week left to go, I’m getting panicky about the thesis, yet at the same time still moderately confident. Pretty much all that’s needed is editorial tidying of the various chapters, plus a bit of work on two of the parsimony analyses. Everything else of interest is being untouched until thesis completion, which is frustrating as there’s so much to post about, so many papers to write. Oscine phylogeny, the discovery of the Odedi, the resurrection of Mecistops, Steep Holm and the biggest slow worm ever, rhinogradentians. It’ll have to wait, alas.

Meanwhile… given that I’ve now produced several posts on cryptozoology I’m hoping that I don’t seem obsessed with the subject (I was also getting concerned a while back that I was coming across as someone obsessed with death, which I why I delayed the much-awaited text ‘when animals die in trees’). But here’s another cryptozoology post. It has a long back-story that I won’t cover here, but I’ll come straight to the point and say that I have found it impossible to get it published. So, in the end, I figured I may as well post it.


There are times when I wonder if it’s really worth bothering with the field of cryptozoology at all. Indeed most (but not all) of my colleagues in the world of academic zoology largely dismiss cryptozoology as an area dominated by wishful thinking and the lunatic fringe and, as someone trying to earn both a Ph.D. and a reputation as a credible scientist, I have certainly not done myself any favours by alerting my academic colleagues to my interest in cryptids*. Conversely, I am frequently accused by those within the cryptozoological community of dismissing cryptozoology in its entirety, simply because I have tried to advocate a critical, sceptical perspective**.

I will maintain my genuine interest, however, because - unlike my more dismissive colleagues - I know that the existence of a fair number of cryptids is supported by at least some reasonable evidence, and I know this because I have gone to the trouble of obtaining and reading the literature on the subject. I also know that, contrary to uninformed criticisms, cryptozoology is not per se based on wishful thinking, on personal belief, or on a lack of critical thought, and there is absolutely and unquestionably no contradiction between pursuing an interest in cryptids and employing scientific methodology (Arment 2004). Heuvelmans (1982) wrote that ‘Cryptozoology aspires to a true skepticism [sic], that which opposes both an a priori incredulity, and a naïve willingness to believe’ (p. 12), so this has always been true. Furthermore, despite the rampant speculation rife in cryptozoology and the reliance in the field on anecdotal evidence, it is not a pseudoscience given that it involves the formulation of testable hypotheses that could, theoretically, be subjected to empirical testing. While it is certainly true that few people involved in cryptozoological research are collating and analysing their data in a manner comparable with that of other branches of science (indeed most cryptozoological research is manifested as popular or semi-technical writing), this does not mean that such potential does not exist, as demonstrated by empirical studies on cryptozoological data (e.g. Fahrenbach 1998, Daegling & Schmitt 2000, Heinselman 2001).

However, it is unfortunate that cryptozoological writing continues to be plagued with naivety, sloppy thinking and an almost total absence of self-correction and internal criticism. A recent debate, played out in the letters pages of Fortean Times (Naish 2005, Shuker 2005a-b), has prompted me to revisit several areas that still seem to require clarification, or at least restating.

Accuracy and self-correction in cryptozoological writing

It is entirely appropriate that I have been accused of being pedantic when reviewing certain cryptozoological works. This is because I feel strongly that cryptozoologists should go to great trouble to ensure that their writings are technically accurate and up to date with the rest of zoology. While some may regard this perspective as elitist, unsympathetic or simply arrogant, I remain dismayed that so many clumsy and misleading errors clutter the cryptozoological literature. Despite evasive comments to the contrary, the pointing out of such errors is directly relevant to cryptozoology as a whole, and for several reasons.

Science proceeds by self-correction. It is clear that our current understanding of the universe is plagued with errors and that an untold number of ideas and theories are confused, flawed or wrong. As new data comes along, we can update and correct these problems and thus proceed to an improved understanding. This internal self-correction, practised virtually every time a new experiment or study or observation is published, is an integral part of the scientific process, and scientists continually argue among themselves as to how data should be interpreted. While it’s certainly true that cryptozoology can proceed via self-correction as much as any other science (Arment 2004, pp. 139-140), it’s notable that (in my opinion) there is not as much of this going on as there should be. Accordingly I have often been critical of some writers when reviewing their published works because, quite simply, few others seem to do this. We desperately need more internal criticism within cryptozoology: more pedantry, more nit-picking, less tolerance of poorly supported theories and proposals, and a lot more arguing about the interpretation of data. Cryptozoology needs extensive self-correction if it is to survive and thrive, and cryptozoologists should quit being so nice to each other and start engaging in spirited discussions about the data.

Furthermore, cryptozoology suffers from an image problem, being unfairly regarded by many in academia as the haunt of poorly informed amateurs, rather than of anyone who might actually know what they’re talking about. The problem is that the former opinion is endorsed by many cryptozoological articles and books where the number of factual errors is high and the application of critical thought is low. While we can’t all be experts in every area we express an interest in, we as researchers have a responsibility to ensure an appropriate level of scholarship, and cryptozoologists have a duty to employ rigour and accuracy in their publications. The profile and standing of cryptozoology in the zoological community, and the significance of its results and areas of research, would be improved if cryptozoological writings were more technically proficient and less cluttered with errors.

The ‘prehistoric survivor paradigm’

In my published cryptozoological writings (Naish 1996c, 1998, 2000, 2001a, 2003a), I have argued, for various reasons, that ostensible prehistoric survivors such as sauropods, basilosaurids and plesiosaurs almost certainly do not lie at the bottom of cryptid reports, nor is there any good reason to think that they might. Conversely, others (e.g., Shuker 1995) have argued that these fossil animals are the only ones that correspond to the relevant cryptids. While the evidence from the fossil record is clearly at odds with the ‘prehistoric survivor paradigm’ (PSP from hereon), it should be noted that the raw cryptozoological data (viz, eyewitness testimony) does not support the PSP either. On this matter I have been accused of two major failings: (1) refusing to acknowledge the possibility of evolutionary modification of fossil groups that might have survived to the present, and (2) of ‘failing to replace the discounted interpretations with hypotheses of [my] own’ (Shuker 2005b, p. 76).

Regarding the first point, the idea that certain cryptids might be the highly modified descendants of known fossil forms is, while of course not impossible, highly improbable and strikingly like special pleading. It is highly suspicious that the modern ‘evolved’ descendants of these fossil forms closely recall historical representations of these groups (e.g., those from Victorian times), rather than the representations supported by contemporary evidence. It should also be noted that some fossil groups argued by the PSP to have undergone a significant amount of hypothetical evolution were in fact highly conservative during their known geological range (Naish 2003a), making the idea of modern ‘evolved’ forms unlikely from the point of view of the evidence.

Perhaps most importantly, rather than imagine that hypothetical modern descendants of fossil taxa have evolved a whole suite of physiological and morphological features not present in their fossil ancestors, it should be noted that the relevant cryptids more recall other possible identities. A review of long-necked aquatic cryptid sightings (the very same cryptids regarded by some authors as representing possible ‘evolved’ plesiosaurs) shows that all the features reported by witnesses are seen in pinnipeds (Naish 2000, p. 43), some of which are, or were, large enough and long-necked enough to correspond to the relevant cryptids. Unsurprisingly, I feel that the notion of peculiar pinnipeds is more likely than the idea of modern plesiosaurs.

Where are the replacements?

On several occasions it has been asserted that, given my rejection of the PSP, the onus is on me to provide replacement hypotheses. It has been stated, for example, that I have ‘[Failed] to replace the discounted interpretations with hypotheses of [my] own’ and that ‘Replacing one model with another is the basis of scientific advancement, so where, for example, are Naish’s proposed identities for cryptids that he dismisses as living archaeocetes, plesiosaurs, sauropods, etc?’ (Shuker 2005b, p. 76). This is naïve, as it is entirely appropriate – given the lack of good evidence for the aquatic cryptids relevant here – to conclude that a satisfactory answer cannot presently be provided. I have stated exactly this before when challenged with the exact same criticism from the exact same worker (Naish 2000, p. 44; 2001a, pp. 78-79) and I am not the only author to have expressed this opinion (Burton 1960, p. 775; Scott & Rines 1975, pp. 466-467; LeBlond & Bousfield 1995, pp. 81-83; Bauer 2002, p. 235).

In any case, I have proposed replacements. As discussed above, I have noted on several occasions that large long-necked pinnipeds better explain sightings of long-necked aquatic cryptids than do hypothetical extant plesiosaurs, and I have also noted that long-bodied delphinidans or other odontocetes might explain some sightings of serpentine aquatic cryptids (Naish 2000, 2001a, 2003a).

However, I am also of the opinion that far fewer aquatic cryptid reports really describe unknown species than has classically been thought. A comprehensive review of reported sea serpent carcasses (Roesch 1997, 1998a-b, 1999) left its author wondering where all the real sea serpent carcasses were; virtually all the photographic evidence purporting to show certain aquatic cryptids can be satisfactorily explained away (Raynor 2001); and Paxton (2004) and Paxton et al. (2004) have highlighted the point that too few identities have been considered when reports of aquatic cryptids have been examined. While it seems likely that at least some unknown species of large aquatic vertebrate await discovery, we can now doubt the idea that they will match the creatures cryptozoologists have been writing about.

A call to arms

Cryptozoologists should not feel upset or insulted by the assertion that their writings often lack an appropriate level of scholarship. Rather, it should be regarded as an admonition encouraging them to combine their often laudable field and literature research with improved access to contemporary information. In an age where more information, and more individual specialists and experts, are more easily accessible than ever before, there is little excuse for a lack of fact-checking. I strongly urge all cryptozoological writers and researchers to consider getting their writings checked prior to publication.

Despite its long history and advocation by many of the most important researchers in the field, cryptozoology has matured enough for us to be able to reject the prehistoric survivor paradigm as a reasonable interpretation of what evidence we have for the relevant cryptids. Increasingly, it seems anachronistic to interpret cryptids as late-surviving relicts of well-known fossil groups and I note that few recent writers have endorsed the PSP. Not only is the PSP contrary to most lines of evidence, it is also the least likely option when the eyewitness data is critically examined. Needless to say, this doesn’t negate the evidence for the relevant cryptids nor, in my opinion, does it make cryptozoology any less interesting.


* To those unaware of my cryptozoological research: during the 1990s I engaged in amateur analysis of poorly known and cryptic whales and dolphins (Naish 1995, 1996a-c, 1997a-c, 1998b), published analyses of various photographic pieces of evidence purporting to show sea or lake monsters (Naish 1996d, 1997d-e), and produced articles on some controversial areas of British mammalogy (Naish 1997f-g). More recently I have published articles advocating a sceptical (but not dismissive) approach to the study of aquatic cryptids (Naish 2000, 2001a). Today, as a researching palaeozoologist busy with Lower Cretaceous dinosaurs, I continue to publish articles of cryptozoological interest when this is possible (Naish 2001b, 2003b-c, 2004). I try to maintain an active role in the cryptozoological community, participating in conferences, online discussions and fieldwork.

** Following the publication of my Fortean Times article on aquatic cryptids (Naish 2000) several responses appeared accusing me of ‘[dismissing] the whole cryptozoology field and sea serpents in particular’ (pers. comm. from a correspondent).

PS - in the photo above, spot the panda and the ABC skull.


For discussion on various of the points covered here, I thank Richard Freeman, Charles Paxton, Karl Shuker, Ben Speers-Roesch and Anthony Russell. I thank Loren Coleman and Chad Arment: their interest in my ideas resulted in the publication of Naish (2003a). Jeff Liston and Ben Speers-Roesch provided comments that improved the manuscript.

Refs - -

Bauer, H. H. 2002. The case for the Loch Ness “monster”: the scientific evidence. Journal of Scientific Exploration 16, 225-246.

Burton, M. 1960. Loch Ness monster: a reappraisal. The New Scientist 8 (201), 773-775.

Daegling, D. J. & Schmitt, D. O. 1999. Bigfoot’s screen test. Skeptical Inquirer May/June 1999, 20-25.

Fahrenbach, W. H. 1988. Sasquatch: size, scaling and statistics. Cryptozoology 13, 47-75.

Heinselman, C. 2001. Eastern Sasquatch Analysis: Potential Patterns or Dubious Data? Craig Henselman (Francestown, New Hampshire).

Heuvelmans, B. 1982. What is cryptozoology? Cryptozoology 1, 1-12.

LeBlond, P. H . & Bousfield, E. L. 1995. Cadborosaurus: Survivor From the Deep. Horsdal & Schuber Publishers Ltd (Victoria, Canada), pp. 134.

Naish, D. 1995. Cryptocetology: introducing a new branch of cryptozoology. Animals & Men 7, 19-27.

- . 1996a. Cryptocetology: the page 254 story. Animals & Men 8, 23-29.

- . 1996b. Ancient whales, sea serpents and nessies part one: pros and cons. Animals & Men 9, 16-23.

- . 1996c. Ancient whales, sea serpents and nessies part 2: theorising on survival. Animals & Men 10, 13-21.

- . 1996d. Analysing video footage purporting to show the “migo” – a lake monster from Lake Dakataua, New Britain. The Cryptozoology Review 1 (2), 18-21.

- . 1997a. Thar she’s blown away. Fortean Times 104, 47.

- . 1997b. Are there narwhals in the Southern Hemisphere? Exotic Zoology 4 (2), 3.

- . 1997c. The southern white whale. Exotic Zoology 4 (5), 3-5.

- . 1997d. The migo is (probably) a crocodile. In Downes, J. (ed) The CFZ Yearbook 1997. CFZ (Exeter), pp. 51-67.

- . 1997e. Another Caddy carcass? The Cryptozoology Review 2 (1), 26-29.

- . 1997f. Southwest England’s small carnivorans: a case of ferreting through the literature. The Cryptozoology Review 1 (3), 23-31.

- . 1997g. Further notes on unrecognized British mustelids. The Cryptozoology Review 2 (2), 28-31.

- . 1998a. Tyrannosaurs, terror birds, touracos and tamanduas: the hottest news in vertebrate palaeontology. Animals & Men 17, 18-27.

- . 1998b. A possible new species of ziphiid whale. The Cryptozoology Review 3 (2), 25-28.

- . 2000. Where be monsters? Fortean Times 132, 40-44.

- . 2001a. Sea serpents, seals and coelacanths. In Simmons, I. & Quin, M. (eds) Fortean Studies Volume 7. John Brown Publishing (London), pp. 75-94.

- . 2001b. How to approach a winged humanoid. Archived at

- . 2003a. Darren Naish on plesiosaurs, basilosaurs, and problems with reconstructions. North American BioFortean Review 5 (3, Issue # 12), 10-19.

- . 2003b. The late survival of Homotherium in Europe confirmed. Animals & Men 31, 31-37.

- . 2003c. Downfall of the Yarri, or will the real Thylacoleo please stand up? Archived at

- . 2004. New Zealand’s giant gecko: a review of current knowledge of Hoplodactylus delcourti and the kawekaweau of legend. The Cryptozoology Review 4 (2), 17-21.

- . 2005. Taxonomic comeback (response to Shuker 2005a). Fortean Times 196, 76.

Paxton, C. G. M. 2004. Giant squids are red herrings: why Architeuthis is an unlikely source of sea monster sightings. The Cryptozoology Review 4 (2), 10-16.

- ., Knatterud, E. & Hedley, S. L. 2004. Cetaceans, sex and sea serpents: an analysis of the Egede accounts of a “most dreadful monster” seen off the coast of Greenland in 1734. Archives of Natural History 32, 1-9.

Raynor, D. 2001. Eyewitness evidence and the remains of the Loch Ness monster. In Heinselman, C. (ed) Dracontology Special Number 1: Being an Examination of Unknown Aquatic Animals. Craig Heinselman (Francestown, New Hampshire), pp. 127-128.

Roesch, B. S. 1997. A review of alleged sea serpent carcasses worldwide (part one – 1648-1880). The Cryptozoology Review 2 (2), 6-27.

- . 1998a. A review of alleged sea serpent carcasses worldwide (part two – 1881-1896). The Cryptozoology Review 2 (3), 25-35.

- . 1998b. A review of alleged sea serpent carcasses worldwide (part three – 1897-1906). The Cryptozoology Review 3 (1), 27-31.

- . 1999. A review of alleged sea serpent carcasses worldwide (part four – 1907-1924). The Cryptozoology Review 3 (3), 15-22.

Scott, P. & Rines, R. 1975. Naming the Loch Ness monster. Nature 258, 466-468.

Shuker, K. P. N. 1995. In Search of Prehistoric Survivors. Blandford (London), pp. 192.

- . 2005a. Taxonomic niceties. Fortean Times 194, 72.

- . 2005b. Taxonomic comeback: Dr Karl Shuker replies. Fortean Times 196, 76.


Wednesday, April 19, 2006

The Cultured Ape, and Attenborough on gorillas

After two days of coding characters for a 118-character, 60-taxon matrix I’m feeling good enough about thesis progress to allow myself some blog time. Though the urge to add posts is strong, it’s a sad fact that, due to lack of time, oh so many very topical things get left behind, only to be completed when time allows. My posts typically reflect, therefore, things that inspired me a minimum of two days ago. On that note, two days ago BBC4 screened a whole night of documentaries on primates. I’ve sat up and watched such things as ‘Natural History Night’ and ‘Dr Who Night’ before – usually they’re a con, the programmes fizzling out round about 10-30, but ‘Primates Night’ (err, if that’s what it was called) wasn’t so thrifty, keeping me in front of the TV until past 01-00 at least. And it was brilliant – the best assortment of TV programmes I’ve seen since, well, ever.

The first episode of the BBC series Cousins (presented by Charlotte Uhlenbroek) was shown: devoted to strepsirrhines, it included some great footage of aye-ayes, indris and sifakas. It’s good, but I’ve seen it before (and got the book [Dunbar & Barrett 2000], but not the t-shirt). Two other documentaries were featured: they are among the best I’ve ever seen, and I really must get hold of copies. The first was essentially ‘Frans de Waal’s guide to cultural primatology’, it was Brian Leith’s award-winning 2002 documentary The Cultured Ape.
Fronted by de Waal, and featuring Jane Goodall and a load of other primatologists whose names I’ve forgotten, The Cultured Ape concentrates on the many discoveries – well known to primatologists but still, it seems, alien to people at large – which show that humans are but one end of a behavioural and psychological spectrum, rather than an island separated from the rest of the animal kingdom. Concepts traditionally regarded as uniquely human, such as the development, maintenance and transmission of cultures, complex communication, and the use of tools, are of course now well recorded for chimps and other primates (e.g. Whiten et al. 1999, Byrne 2002), and a good case can be made that chimps and other non-humans also display less quantifiable traits such as guilt, deception, aesthetic enjoyment and hatred. When gorillas in zoos have looked after children who have fallen into their enclosures, are they not displaying altruism? Reportedly, mortally wounded chimps display behaviour that – if witnessed in a human – would be interpreted as pleading for their life.

On several occasions Goodall has explained the resistance she has received to her anthropomorphic interpretation of chimp behaviour after witnessing what seemed like jealousy, altruism, hatred and so on, and she explained how she learnt to couch these observations in a neutral language in order to get past reviewers. While I can understand that scientists want to avoid anthropomorphism, at the same time it seems unavoidable to conclude that individuals of at least some non-human species have personalities - surely everyone who’s kept pets has experienced this, as Goodall stated on the programme - and can experience many/most of the same things that we can. Yet it seems that traditional ethology denies these as possible for other species, and in saying these things – the chimp enjoyed looking at the waterfall, the chimp felt guilty when it was caught stealing – one would be accused of being un-scientific. Some ethologists even argue that we shouldn’t speak of non-human animals experiencing pain, given that we don’t know that they are really experiencing the same sensation that we associate with that word. I’ve read some of the literature on this area, but I’m no ethologist, and I have no stake in this area. I’m just interested.

The other documentary - Gorillas Revisited With David Attenborough - was altogether different, but just as excellent. One of the most memorable and talked-about scenes from any TV documentary ever is Sir David Attenborough’s 1978 encounter with wild Mountain gorillas Gorilla beringei in the Parc National des Volcans of Rwanda, broadcast in episode 12 (‘A life in the trees’) of the ground-breaking series Life on Earth, first broadcast in 1979. Gorillas Revisited covered the behind-the-scenes history of the 1978 filming, and what has happened to the Rwandan gorillas since. Attenborough was joined by Life on Earth producer John Sparks, cameraman Martin Saunders, and Ian Redmond, former assistant to Dian Fossey and now director of Global Great Ape Conservation. It was a fascinating story, tragically sad in places, uplifting in others.

Most people – even those without a special interest in zoology – know the story of Dian Fossey and the gorillas she studied while at the Karisoke Research Center thanks to the 1988 film (and/or Fossey’s 1983 book) Gorillas in the Mist. So it might come as no surprise to learn that the BBC team sought permission from Fossey to film ‘her’ gorillas, as they’d heard that this group had become habituated (= accustomed to humans). Somewhat surprisingly, Fossey gave enthusiastic approval, and urged Attenborough and colleagues to help promote the gorilla conservation work she, Redmond and her colleagues had initiated. At the time of the filming, Fossey was ill and still devastated by the recent killing of Digit, a young male gorilla who had been speared to death on New Year’s Eve 1977. After the filming, the BBC team were shot at and arrested by the Rwandan army, who were under the impression that the film was being made in order to show what a bad job Rwanda was doing for gorilla conservation. The army also thought that the BBC had been filming Digit’s body. They strip-searched Attenborough and confiscated the film cans, but the crew had cleverly swapped the labels on the cans, so the soldiers were confiscating unused film.

During the Life on Earth sequence one young gorilla clambers all over Attenborough and lies back on Attenborough’s chest. From its behaviour you might assume that this gorilla was a plucky, bold and confident individual. Well, he was named Pablo, and today he is an adult silverback. Another individual who was a youngster when Attenborough encountered him, Titus, is today a silverback who leads a group of 59 animals: the biggest recorded gorilla group ever. Many of the gorillas named by Fossey are doing well today, and have become parents and grandparents, and Fossey will always be remembered for initiating one of the first long-term generation-level studies of a wild mammal population.

If you’ve seen Gorillas in the Mist you’ll know that Fossey’s work was actually inspired by her meeting with a palaeontologist, Louis S. B. Leakey: a great example of a very fruitful crossover between palaeontology and field biology. Prior to Fossey’s work, Rosalie Osborn had studied Mountain gorillas. She also acknowledged Leakey’s involvement in setting up her research (Osborn 1963), and Leakey is also acknowledged by Goodall as initially suggesting that she might study the chimps she eventually became so acquainted with (van Lawick-Goodall 1971). It’s no secret that Leakey regarded women as better suited for observational fieldwork than men, apparently because he regarded women as more observant, and more patient.

Of course, things have not all been rosy in the Virungas. In 1968 half of the Parc National des Volcans was taken for pyrethrum cultivation (ironically, grown for use in Europe as an environmentally-friendly alternative to DDT) and there were plans, backed by the European Development Fund, to replace even more of the park with pyrethrum (Harcourt 1981). Poaching was a serious problem that Fossey and her successors have had to deal with (snares are set for hoofed mammals, but gorillas get caught and injured in them), and during the 1970s several gorillas were shot. Following the humanitarian crisis that engulfed the region following the civil war and resultant genocide of April-July 1994, rebels invaded the park and looted the homes and facilities, and murdered several of the people employed to keep the gorillas safe from poachers. Rebels also killed gorillas, and anti-poaching trackers, in 2001. And of course Fossey herself was murdered in 1985.

From a population that was thought to be around 600 in 1960, Rwandan Mountain gorillas had dwindled to an estimated low of 200 or so by 1980. Today, there are around 380 animals. That’s better than it was, but still pitifully low.

The above photo, of the Karisoke gorilla Cantsbee (named by Fossey) is from here.

If primates interest you, check out my posts on kipunjis and mangabeys. And for the latest news on Tetrapod Zoology do go here.

Refs - -

Byrne, R. W. 2002. Social and technical forms of primate intelligence. In de Waal, F. B. M. (ed) Tree of Origin. Harvard University Press (Cambridge, Mass. & London), pp. 145-172.

Dunbar, R. & Barrett, L. 2000. Cousins: Our Primate Relatives. BBC Worldwide, London.

Harcourt, A. H. 1981. Why save the mountain gorilla? Wildlife 23 (2), 22-26.

Osborn, R. M. 1963. Observations on the behaviour of the Mountain gorilla. Symposia of the Zoological Society of London 10, 29-37.

van Lawick-Goodall, J. 1971. In the Shadow of Man. William Collins Sons & Co, London.

Whiten, A., Goodall, J., McGrew, W. C., Nishida, T., Reynolds, V., Sugiyama, Y., Tutin, C. E. G., Wrangham, R. W. & Boesch, C. 1999. Cultures in chimpanzees. Nature 399, 682-685.

Saturday, April 15, 2006

The hands of sauropods: horseshoes, spiky columns, stumps and banana shapes

I’ve stated before on this blog that I do quite a bit of consultancy work for companies that produce prehistoric animal books for children. In advising and assisting artists as often as I do, I find that they consistently screw up on the same things, every time. One of the biggest problem areas seems to be the hands and feet of sauropod dinosaurs – I reckon that every single artist whose work I’ve had to check has screwed up on these. By the way, the artists I’m talking about here lack palaeontological expertise or training: I’m not talking about your Luis Reys, Todd Marshalls and Mark Halletts, but rather about wildlife artists who find themselves being asked to illustrate dinosaurs.

I also want to note that in no way is it the ‘fault’ of the artists concerned, given that (1) they’ve mostly based what they’ve done on the published work of those who have gone before them, and (2) while many of them have a history of working with palaeontologists, none of the experts they’ve been advised by before have bothered to tell them what they’ve been getting wrong. In fact I note that book-writing palaeontologists in general (you know who you are) rarely seem to bother providing their artists with any information, nor correct their mistakes, hence the incredible number of god-awful restorations that clutter the literature. Incidentally, this situation is getting worse as companies increasingly use CG images produced by people who seem to know nothing about animals, let alone fossil ones. But enough of that.

To save myself work in the future it occurred to me that it might be a good idea to post on sauropod hands and feet: that way, I can just direct interested parties to this web page in future, and save myself the usual to-ing and fro-ing of notes, scans, and scribbled on diagrams. Several people have already produced overviews of sauropod hand and foot morphology, but unfortunately they’re somewhat obscure and inaccessible to many. Greg Paul (1987) discussed in detail what sauropod hands and feet probably looked like, based on trackways and morphology, and provided a summarized version of the same information in his Japanese book The Complete Illustrated Guide to Dinosaur Skeletons (Paul 1996). Tracy Ford (1999) also published a guide to restoring sauropod hands and feet. Numerous technical studies describe or review sauropod hands and feet, with the most useful works being Christiansen (1997), Bonnan (2001, 2003, 2005) and Apesteguía (2005).

The basics

Let’s note to begin with that sauropod hands and feet were only very superficially like those of elephants, and in fact in several details were fundamentally different. Sauropod hands, in particular, are unique in that the metacarpals did not spread out from the wrist as they usually do in tetrapods, but were arranged in a vertical column. My biggest peeve concerning restorations of sauropod hands and feet is that people seem unable to resist the temptation to illustrate multiple claws sticking out all over the place, or to depict hooves on all of the digits. As we’ll see, the evidence is against both details. I know that many skeletal mounts give the animals multiple claws on the hands and/or feet, but that’s because the mounts are inaccurate, outdated composites.

I should note here that the following discussion applies only to members of Eusauropoda, given that it now seems that basal sauropods outside of Eusauropoda lacked the distinctive hands and feet of the better known, fully graviportal sauropods.

The metacarpal colonnade

As noted, the eusauropod hand is formed from a columnar arcade of five vertically arranged metacarpals. If you were to look at the animal’s hand from underneath (the plantar surface), the distal metacarpal tips would be seen to be arranged in a semi-circle, and the posterior surface of the hand would be concave. The hand was not backed by a pad (as McGowan (1991) wrongly stated), as it is in elephants. There is no doubt that this configuration was the case in life, as it’s verified by numerous horseshoe-shaped hand tracks. In a new, as-yet-unpublished sauropod from the Lower Cretaceous of the Isle of Wight, it’s been claimed that the first and fifth metacarpals virtually touch on the posterior surface of the hand, but this is unique so far as we know (this animal wouldn’t have left horseshoe-shaped tracks, but subcircular ones… if the proposed interpretation is valid, and it might not be). An even more peculiar claim – in fact it’s downright ridiculous – is that sauropods walked with their fingers curled under the distal ends of the metacarpals (Beaumont & Demathieu 1980). This is totally at odds with the morphological and trackway evidence and can be disregarded.

Not only did the metacarpals form this unique tubular structure, they and their digits seem to have been bound together to form a sort of pseudo-hoof: the digits didn’t splay outwards from the metacarpus, but were bound together with them, nor did digits II to V possess hooves, claws or nails. This is supported by both anatomy and trackways, so distinct digits were almost certainly not visible in life.

Thumb claws, or lack of them

Claws were absent from all digits except for digit I (the thumb). This thumb claw varied in size, shape and orientation among the sauropod groups: it was particularly big in diplodocoids, where it was also laterally compressed and notably deep, and clearly separated from the rest of the metacarpus. In contrast, in brachiosaurids it was small, subtriangular in cross-section, and not separated from the rest of the metacarpus. In forms with large pollex claws (like diplodocoids), the anatomy of the penultimate phalanx and the distal end of the first metacarpal indicates that some flexion and extension of the claw was possible: in other words, these sauropods could both lift and lower their claws (albeit not by much compared to what was possible in other dinosaurs).

What did sauropods do with this lone thumb claw? Pretty much every conceivable function has been proposed, including fighting, digging, ripping foliage or tree trunk gripping. The claw’s anatomy and range of motion led Upchurch (1994) to conclude that a trunk-gripping function was most likely, but if this is right then it seems odd that titanosaurs – the sauropods perhaps best suited for bipedality and rearing – were the ones that lost the claws.

That’s right: even the thumb claw was not present in all eusauropods. During the evolution of titanosauriform macronarians (the group that includes brachiosaurids and titanosaurs) the thumb claw was reduced in size and eventually lost altogether. We know that brachiosaurids such as Brachiosaurus possessed a short, small thumb claw, but Lower Cretaceous trackways apparently produced by other brachiosaurids indicate that the thumb claw was absent in these forms (it’s been suggested that the thumb claw was still present in these forms, but that it was so small that it failed to leave an impression. I find this less likely than the idea that the claw really was absent). With the exception of the controversial Jurassic form Janenschia (and probably a few basal taxa from the Cretaceous), titanosaurs were all devoid of thumb claws.

Pads and spiky tubercles

But there’s more - derived titanosaurs lacked not just claws, but finger bones too, and thus fingers. Their column-shaped hands were bizarre fingerless stumps, and they walked on the distal ends of the metacarpals, which is pretty odd to say the least. As described by Apesteguía (2005), the distal ends of the metacarpals in fingerless titanosaurs were wider and more rectangular than those of other sauropods, and with unusual sculpturing. The latter feature suggests that some kind of cushioning tissue encased the metatarsal ends, and a few titanosaurs preserve what appears to be some kind of soft tissue in this area.

Evidence for unusual soft-tissue structures on the sauropod metacarpus might have been present in other sauropods, according to recently described trackway evidence. A manus impression from the Upper Jurassic of Lourinhã in Portugal – probably produced by a brachiosaurid – preserves vertical score marks on its sides that seem to have been produced by rough tubercles on the metacarpal surface (Milàn et al. 2005). These authors proposed that at least some sauropods had spiky skin covering the distal end of the metacarpus, though how widespread this was among sauropods we don’t know.

Banana-shaped first metacarpals: why?

While all five metacarpals in most eusauropods were more or less straight and parallel, this was not true of some titanosaurs. In these forms the first metacarpal was curved outwards at its distal end, and thus roughly banana-shaped. This is first seen in Janenschia, in which a thumb claw was present, but it’s also the case in various other taxa, including Andesaurus and Argyrosaurus. Apesteguía (2005) made the intriguing suggestion that the bowed first metacarpal may first have evolved in claw-bearing basal titanosaurs in order to help support the claw, that it was then later retained when the claw was lost, and that it was later reversed (back to the straight condition) in derived lithostrotian titanosaurs.

This raises the question as to why a bowed first metacarpal was needed ‘to help support the claw’ however, given that other sauropods with thumb claws had straight, rather than bowed, first metacarpals. In Janenschia, a raised lip around the outer surface of the first metacarpal’s distal end is very nearly in contact with the dorsoproximal part of the claw. This creates the impression that the metacarpal’s distal end had evolved to help conduct stress along the curved ungual’s dorsal margin. If that’s true (let me emphasize that this is just an idea), it could mean that the thumb claw was used in a manner quite different from that of other sauropods. Maybe the claw tip was actually used for piercing something: presumably a substrate, or bark. Any better ideas?

I had planned to cover sauropod feet as well, but that’ll have to wait for a future post. The image used above was borrowed from…

Refs - -

Apesteguía, S. 2005. Evolution of the titanosaur metacarpus. In Tidwell, V. & Carpenter, K. (eds) Thunder-Lizards: The Sauropodomorph Dinosaurs. Indiana University Press (Bloomington & Indianapolis), pp. 321-345.

Beaumont, G. & Demathieu, G. 1980. Remarques sur les extremités antérieures des sauropodes (reptiles, saurischiens). Compte Rendu des Séances de la Société de Physique et d’Histoire Naturelle de Genève 15, 191-198.

Bonnan, M. F. 2001. The evolution and functional morphology of sauropod dinosaur locomotion. Chapter 3: osteology of the forelimb. Unpublished phd thesis, Northern Illinois University.

- . 2003. The evolution of manus shape in sauropod dinosaurs: implications for functional morphology, forelimb orientation, and phylogeny. Journal of Vertebrate Paleontology 23, 595-613.

- . 2005. Pes anatomy in sauropod dinosaurs: implications for functional morphology, evolution, and phylogeny. In Tidwell, V. & Carpenter, K. (eds) Thunder-Lizards: The Sauropodomorph Dinosaurs. Indiana University Press (Bloomington & Indianapolis), pp. 346-380.

Christiansen, P. 1997. Locomotion in sauropod dinosaurs. Gaia 14, 45-75.

Ford, T. L. 1999. How To Draw Dinosaurs, book 1. T. L. Ford (privately published).

McGowan, C. 1991. Dinosaurs, Spitfires, & Sea Dragons. Harvard University Press (Cambridge, Mass. & London).

Milàn, J., Christiansen, P. & Mateus, O. 2005. A three-dimensionally preserved sauropod manus impression from the Upper Jurassic of Portugal: implications for sauropod manus shape and locomotor mechanics. Kaupia 14, 47-52.

Paul, G. S. 1987. The science and art of restoring the life appearance of dinosaurs and their relatives - a rigorous how-to guide. In Czerkas, S. J. & Olson, E. C. (eds) Dinosaurs Past and Present Vol. II. Natural History Museum of Los Angeles County/University of Washington Press (Seattle and London), pp. 4-49.

- . 1996. The Complete Illustrated Guide to Dinosaur Skeletons. Gakken.

Upchurch, P. 1994. Manus claw function in sauropod dinosaurs. Gaia 10, 161-171.

Sunday, April 09, 2006

Hunting Green lizards in Dorset: new aliens or old natives?

If you like amphibians and reptiles (or, if you want to be as zoologically specific as possible: lissamphibians and non-avian reptiles), Britain is a pretty crappy place to live, with only a handful of natives. But strange things are happening: the diversity of our herpetofauna is being boosted by newly-appearing aliens, and some of our ‘long-established aliens’ are turning out to be genuine natives. Yesterday I spent the better part of the day in the field looking for lizards, and of the three species I saw, two are not natives. Probably.

The trip (organized by the Southampton Natural History Society) was to Southbourne and Boscombe Cliffs, Dorset, and the main purpose was to see Western green lizards Lacerta bilineata*. This is a large lacertid - c. 130 mm snout-to-vent, and c. 300 mm in total length - that inhabits much of continental Europe except for the north-east: it’s also devoid from much of Spain and Portugal where it’s replaced by its close relatives the Ocellelated lizard L. lepida and Schreiber’s green lizard L. schreiberi. Vivid green and decorated with fine dark stippling, and with a yellowish throat that turns blue in breeding males, it’s an impressive looking, distinctive animal. It prefers to live in sunny places where there is bushy vegetation, and it even climbs quite high in bushes and shrubs to forage or bask (Arnold et al. 1992).

* This species was until recently included in L. viridis but a 1997 revision separated L. bilineata and L. viridis as separate species (Amann et al. 1997). This complicates things, as it means that pre-1997 authors are not referring to our modern concept of L. viridis when they use this name. Indeed, much of the text you're about to read may be inaccurate as a result of this.

While we know (from fossils) that green lizards formerly inhabited Britain, they don’t appear to be native to our islands today, with the exception of Jersey where they inhabit south-facing coastal heaths and dunes. They also occur on neighbouring Guernsey, but here they’ve apparently been introduced from Jersey (Beebee & Griffiths 2000). It follows, then, that the announced discovery of a green lizard colony on the well-vegetated Dorset cliffs of Bournemouth in August 2003 came as quite a surprise. These were the lizards we had gone to see: we got to within very close range of a lone male who was sunning himself among some bramble, and he’s the animal featured in the photos above (the top photo is a closeup, and the lower one shows the original field of view as seen by my camera. A red circle is drawn around the lizard). They’re not the only lizards here: there are also Viviparous or Common lizards Zootoca vivipara* and Wall lizards Podarcis muralis (both of which we saw too by the way. Damn we’re good). The former is definitely a native, while the latter is almost certainly not. What are these aliens doing here, and are they aliens or not?

* This species is more usually known as Lacerta vivipara but, because Lacerta is otherwise paraphyletic, Mayer & Bischoff (1996) have argued that it warrants generic distinction.

Green lizards are so pretty and charismatic that it comes as no surprise to learn that there have been numerous attempts to introduce them to Britain. Lever (1977) discussed introduction attempts that took place in Wales, Ireland, and Devon, the Isle of Wight, Surrey and Gloucestershire in England, with the earliest taking place in 1872. Some of these introduction attempts involved literally hundreds of animals, and must have been expensive undertakings. Numerous other releases are also known to have occurred, but, because there has never been any good indication of breeding occurring, Beebee & Griffiths (2000) noted that ‘on current evidence the species is not established in this country’ (p. 208). Even so, lizards introduced to St Lawrence on the Isle of Wight in 1899 were apparently still there in 1936, so some introduced colonies have persisted for quite a while.

But there are also quite a few historical accounts that document Green lizards in places where, so far as we know, deliberate releases haven’t occurred. As early as 1769, Gilbert White wrote of seeing ‘Guernsey’ lizards. It is generally thought that he had misidentified the definitely native Sand lizard L. agilis however (this is a stocky, short-limbed species which, although often green, is altogether easy to distinguish from L. bilineata, and L. viridis and related species. It occurs as a native in Surrey, Dorset and Merseyside). Elsewhere, however, supposed green lizards were reported during the 1860s and 70s at Sidmouth and elsewhere in Devon, and during the 1900s in Dorset. One of the Devon records was made by a Mr John Wolley from Guernsey. He was apparently quite confident that the lizards he saw in Devon were exactly the same as the green lizards of Guernsey.

All of these reports were later dismissed as further misidentifications of Sand lizards, and while this might have been the case for some of the accounts, in others it appears unlikely, simply because the lizards described don’t match this species. In some of the Dorset records it is noted that the lizards were nearly 300 mm long, for example, which is way too big for L. agilis. On the basis of these historical records, Jon Downes (1994) proposed that viable feral colonies of green lizards existed in Devon and Dorset, and that they were probably introduced from either France or the Channel Islands. He became disappointed that his idea was ‘ignored by the zoological establishment’ and that ‘two famous zoologists (who shall remain nameless) told us that the theory was arrant nonsense. The paper was returned with a brusque letter from several zoological magazines and after a while we just gave up’ (Downes 2003, p. 13). Given that, as noted above, relatively long-lived feral colonies had been reported earlier from the Isle of Wight, however, it would seem likely that Jon was right.

The presence of what appears to be a viable, breeding colony, this time at Bournemouth, led Jon (Downes 2003) to write an article titled ‘Told u so’ [sic]. However, because there’s no evidence that the Bournemouth colony is anything to do with the historical Devon and Dorset records discussed by Jon, it’s not entirely satisfactory to claim that his contention has been vindicated. Then again, the fact that the Bournemouth colony is apparently viable and spreading (breeding is thought to have occurred) suggests that other colonies in southern England may well have been capable of this too. The Bournemouth colony was discovered by herpetologist Chris Gleed-Owen of the Herpetological Conservation Trust when he was on his way to work one day, and the colony is located just a few hundred metres away from Gleed-Owen’s office (Gleed-Owen 2004).

Why are the lizards there? Gleed-Owen has suggested that they are dumped pets that have since bred. Could they have been introduced accidentally from the Channel Islands, or the continent, as Jon suggested for the other possible colonies? To answer this you’d need to know what sort of imports Bournemouth receives from abroad, and I haven’t bothered to check that out. Finally, could they be late-surviving, hitherto-overlooked natives? This possibility has been inspired by the recent discovery that the (now extinct) British Pool frogs Rana lessonae of Norfolk and Cambridgeshire were almost certainly natives, and not continental introductions as usually thought. It’s also now being suggested that the European tree frog Hyla arborea colonies of the New Forest are also natives. Gleed-Owen regards the possibility of native status for the Bournemouth lizards as ‘unlikely, but not impossible’.

I have to say that I think it’s unlikely for two reasons: (1) the location is well known to naturalists and is regularly well explored. If the lizards occurred there long prior to 2003, it’s difficult to believe that they would have been overlooked for so long. (2) All of Britain’s native amphibians and reptiles have European ranges that extend far to the north-east, usually incorporating Scandinavia. They are therefore relatively cold-tolerant, and this explains why they were able to colonise post-glacial Pleistocene Britain before the English Channel severed the continental connection about 9000 years ago. Conversely, green lizards are not animals of the north-east, which suggests that they wouldn’t have been able to colonise post-glacial Britain during that brief critical phase, as our definite natives did. But the exciting possibility that they are natives can’t be totally dismissed, and should be tested further.

Given that I’ve now posted on British big cats and introduced eagle owls, as well as green lizards, I will admit that I’m very interested in the alien species we have here, and the implications they have for ecology and diversity. Most people know that we already have, or have had, a lot of bizarre alien species in our islands (including bears, binturongs, wallabies, coypu, Edible and Garden dormouse, Midwife toads, American bullfrog, Ring-necked parakeets and so many others), but given the climatic changes that are occurring, it is likely that our fauna will change dramatically in future decades as old natives find life increasing difficult, and as new aliens find survival here easier.

For the latest news on Tetrapod Zoology do go here.

Refs - -

Amann, T., Rykena, S., Joger, U., Nettmann, H. K. & Veith, M. 1997. Zur artlichen Trennung von Lacerta bilineata Daudin, 1802 und L. viridis (Laurenti, 1768). Salamandra 33, 255-268.

Arnold, E. N., Burton, J. A. & Ovenden, D. W. 1992. Reptiles and Amphibians of Britain and Europe. Collins, London.

Beebee, T. & Griffiths, R. 2000. Amphibians and Reptiles. HarperCollins, London.

Downes, J. 1994. Green lizards in Devon and Dorset? Animals & Men 2, 22-23.

- . 2003. Told u so! Animals & Men 32, 12-13.

Gleed-Owen, C. P. 2004. Green lizards and Wall lizards on Bournemouth Cliffs. Herpetological Bulletin 88, 3-7.

Lever, C. 1977. The Naturalized Animals of the British Isles. Hutchinson & Co, London.

Mayer, W. & Bischoff, W. 1996. Beitrafe zur taxonomischen Revision der Gattung Lacerta (Reptilia: Lacertidae). 1. Zootoca, Omanasaura, Timon und Tiera als eigenstandige Gattungen. Salamandra 32, 163-170.

Monday, April 03, 2006

Why azhdarchids were giant storks

People often talk of getting a ‘culture shock’ when they travel abroad. But in the world of zoological uber-nerdiness, you don’t need to go abroad to experience a culture shock, you merely need to be an exposed to an idea that is shockingly alien and counter-intuitive. I still have fond memories of those days back in 1997 when I first visited the School of Earth & Environmental Sciences at the University of Portsmouth to be interviewed by the man who would later become my phd supervisor, Dave Martill. Of all the surprising things I was exposed to at the time, none was more striking and bizarre than the gigantic wall-mounted display on azhdarchid pterosaurs. Featuring a life-sized wing skeleton, some photos of a grinning German man* holding a bone, and a giant colour mural by John Sibbick, it’s a pretty good exhibition, and eight years later it’s still in the same place.

* Dino Frey, guru of ‘konstruction morphology’

Based on various of their morphological details, I had concluded that azhdarchids were most likely stork-like generalists that made their living by picking up assorted invertebrates and vertebrates, terrestrial and aquatic. Several other workers had also expressed a preference for this hypothesis. But Sibbick’s giant colour mural depicted azhdarchids in an altogether different manner: they were shown wheeling above a vast expanse of ocean, gliding above the water surface and swooping down to grab fish. They were depicted as ‘mega-skimmers’, and Dave was later to explain to me why he and his colleagues favoured this skim-feeding hypothesis. I found it unconvincing and told him about the merits of the stork idea. He disagreed. We still disagree.

Today we have a new pterosaur worker in our research group, Mark Witton, and he’s been looking at the morphology and palaeobiology of azhdarchids, among other things. At the risk of stealing his thunder (sorry Mark), I will say that he, also, is a supporter of the stork-like model. If you combine this with the recent work Dave and I have been doing on the non-azhdarchid azhdarchoids Tupuxuara and Thalassodromeus (the latter of which was claimed to be a skim-feeder), you can understand why the topics of skim feeding and azhdarchid lifestyles have become much discussed within our research group. Mark and I are obviously in happy agreement, but we still have to turn Dave around. I’ve wanted to write up my thoughts on this area for a while now, so here we go.

Interpreting azhdarchid palaeobiology

Since the announcement of its discovery in 1975, Quetzalcoatlus – the best known and best studied azhdarchid – has been imagined in several different ways. Initially it was interpreted as a vulture-like scavenger that soared over the Late Cretaceous landscape in search of dinosaur carcasses. Why was it interpreted this way? Well, apparently because Quetzalcoatlus was a big flying animal found in the same deposits as dinosaur bones (Lawson 1975). From a scientific perspective that’s not exactly compelling.

A second hypothesis was proposed by Langston (1981): that azhdarchids fed on burrowing invertebrates by probing for them in the substrate. This was also adopted by Wellnhofer (1991) (see p. 145, where Wellnhofer states ‘All this allows the possibililty that Quetzalcoatlus used its slender, pointed beak to search in the ground [my emphasis] for the molluscs and crabs that lived in the shallow pools of water’). Like Lawson’s scavenging idea, this appeared to be based on nothing more than circumstantial association of Quetzalcoatlus with other fossils, in this case invertebrate burrows. The same idea was endorsed by Lehman & Langston (1996), though only in an abstract. Lehman & Langston (1996) later came under extremely heavy fire from some workers, but the fact that Langston had actually proposed the probing idea first, and that Wellnhofer had agreed with it, seems to have been missed.

Describing the Asian azhdarchid Azhdarcho, Nesov (1984) was the first to propose a radically different hypothesis: that these pterosaurs might have behaved like Rynchops, the skimmers. These charadriiform birds fly low over the water surface, trawling their unusual, laterally compressed lower jaws through the water, snapping up the fish and crustaceans that they make contact with. However, Nesov didn’t base this idea on any features he observed among members of Azhdarchidae: he assumed that azhdarchids might have behaved this way, simply because other workers had earlier proposed a skimming lifestyle for other Cretaceous pterosaur groups. He wrote ‘If it is assumed that the Azhdarchinae could have flown like the Ornithocheirinae and Pteranodontinae – that is, like the Recent skimmers…’ (p. 42). He went on to propose that azhdarchids might have been swimmers (that’s not a typo) that captured aquatic prey, or that they might have ‘been able to hunt poorly flying vertebrates in the air’. Neither latter idea seems reasonable.

Paul (1987a, b) seems to have been the first to reject the scavenging hypothesis, at least in print, stating of Quetzalcoatlus that ‘Its slender, two-meter beak, with only thin bars around the external nares, is too weak for regular scavenging’ (p. 20). Even better, he suggested a fourth possible lifestyle, proposing (Paul 1987a) that Quetzalcoatlus ‘probably patrolled water courses, like a three-meter-tall stork, picking up fish and small animals’. I found Paul’s argument moderately compelling when I first read it I-don’t-know-how-many-years-ago, and I still find it moderately compelling today. Padian (1988) also rejected the scavenging idea and regarded azhdarchids as heron-like, noting that 'Langston, who knows [Quetzalcoatlus] better than anyone, finds some suggestive resemblances to a heron or egret' (p. 64). Does this mean that Langston had given up on the probing idea? Noting the long, inflexible azhdarchid neck, Halstead (1989) wrote that ‘Quetzalcoatlus had a neck which could only move up and down and was specialized for dipping down into the water to snatch fish’ (p. 160). This could perhaps be construed as agreement with the stork-like model.

In an article devoted exclusively to azhdarchid lifestyle, Iñaki Rodriguez Prieto (1998) argued against the scavenging hypothesis and agreed with Nesov’s skimming idea. Morphological features were used to support the latter concept, but they were either erroneous or just incorrect. Prieto argued that the bill of Quetzalcoatlus was laterally compressed, that terrestrial abilities were very poor, and that the uropatagia would have made the hind limbs functionally similar to the forked tails seen in highly aerial birds like frigate birds, swallows, and some kites. By implication, Quetzalcoatlus was deemed specialized for feeding on the wing, and it was on this basis that Prieto chose to follow the skimming hypothesis. All the features cited by Prieto are problematical, as we’ll see later. Prieto’s article was in Spanish and has been mostly overlooked.

Kellner & Langston (1996) also favoured the skimming hypothesis but did the same thing that Nesov did: they regarded it as ‘at least plausible’ for Quetzalcoatlus on the basis of the fact that it had been ‘previously advocated for Rhamphorhynchus … and later assumed for many other pterosaurs, including the larger toothless pterosaurs’ (p. 231). In other words, they didn’t provide any supporting evidence at all, but merely elected to follow conclusions made for other, morphologically different pterosaur taxa (and, by the way, the concept of skim-feeding in rhamphorhynchids and those other pterosaurs isn’t necessarily any more secure than it is for azhdarchids).

Unwin et al. (1997) noted that ‘unpublished functional studies and the circumstances of their preservation suggest that [azhdarchids] may have been piscivorous … feeding from the water surface while on the wing and using the long neck as a ‘fishing rod’’ (p. 48). They cited an abstract and Unwin’s unpublished thesis when discussing this area, but didn’t elaborate as to why they favoured the skimming hypothesis. Martill (1997), while being harshly critical of Lehman & Langston’s mud-probing idea, also agreed with the skimming hypothesis, but, I would argue (sorry Dave), presented it as a just-so story, not as an evidence-led hypothesis. The presence of a ‘highly streamlined skull’ (p. 73) was used to support skimming behaviour, as was the long stiff neck. Martill et al. (1998) rejected both the scavenging and mud-probing hypotheses, and regarded azhdarchids as ‘aerial piscivores or planktivores’ (p. 57). While noting the inflexibility of the neck, they didn’t provide any supporting evidence for this hypothesis however.

Finally, Bennett (2001) noted that the femora and metatarsal V of Quetzalcoatlus were robust relative to those of other pterodactyloids, and that its feet were larger and more robust than those of ornithocheiroids. These observations led him to regard Quetzalcoatlus as ‘better suited to terrestrial locomotion than Pteranodon’, and specialised for feeding on the ground. He wrote that ‘Quetzalcoatlus remains have been found far inland where they seem to have been heron- or stork-like in their ecology despite their great size’ (p. 136).

So that’s what’s in the literature: four hypotheses (scavenger, skimmer, stork and mud-prober). It’s problematical that hardly any morphological features have ever been used to support them, and in fact some of them seem decidedly arm-wavy and intuitive, rather than evidence-led. So in the interests of introducing some hypothesis testing into this area, I’ve listed below all those hypotheses that I consider at least feasible, and have made predictions as to what evidence we would require in order to consider them reasonable. I do not consider Nesov’s ideas that azhdarchids were swimming predators, or that they routinely captured flying vertebrates (presumably other pterosaurs and birds) likely, nor have I considered lifestyles that are obviously discordant with azhdarchid morphology (e.g. that they were deep divers, plunge divers, herbivores, aerial pirates or filter-feeders). I looked at as much literature as I could on form and function in bird bills, and also examined relevant specimens.

The hypotheses

Hypothesis 1: azhdarchids were vulture- or marabou-like scavengers, soaring over land and feeding from the carcasses of large terrestrial vertebrates.
Predictions: proficient terrestrial abilities; bill and head capable of probing into body cavities; bill robust around narial openings; flexible neck; highly developed soaring or gliding skills. Note that hooked bill tips are not necessarily needed for this lifestyle, given that marabou storks and some corvids (e.g. Thick-billed raven Corvus crassirostris) routinely scavenge, yet have pointed bill tips. Witmer & Rose (1991) noted this.

Hypothesis 2: azhdarchids were mud-probers (like sandpipers), pushing their bills into sediment in search of burrowing prey.
Predictions: proficient wading abilities (indicating by long, spreading toes); no need for highly developed soaring or gliding skills; skull should be specialized for probing, either with features allowing powerful gaping, with adaptations allowing rhynchokinesis, with a cross-section recalling that seen in mud-probing birds, and/or with well-developed tactile organs at the bill tip (e.g. Herbst corpuscles); neck should be reasonably flexible. Birds that probe sediment in search of prey have been shown to rely either on touch, on the detection of vibrations produced by the prey, or on the detection of pressure gradients surrounding hard objects (Gerritsen & Meijboom 1986, Piersma et al. 1998, Nebel et al. 2005). Pressure-sensitive organs termed Herbst corpuscles, embedded within pits on the premaxillary and dentary tips, are closely packed and particularly numerous in birds that probe sediments.

Hypothesis 3: azhdarchids were spear-fishers (like herons and anhingas), stalking fish in shallow water and spearing the body of the prey with sharp bill tips.
Predictions: proficient wading abilities (indicating by long, spreading toes) or swimming abilities; sharply pointed, spear-like bill; flexible neck that allows rapid darting of bill towards prey.

Hypothesis 4: azhdarchids were skim-feeders, flying low over the water and trawling the lower jaw through the water. In contrast to that of many other birds, the feeding behaviour and cranial morphology of skimmers has been well described (Arthur 1921, Tomkins 1951, Bock 1960, 1964, Zusi 1962).
Predictions: no need for proficient terrestrial abilities; highly skilled at fast, level flight; lower jaw laterally compressed and blade-like; streamlined bill; jaw joint, back of skull and neck able to withstand sudden jarring, with accessory articulation present between mandible and basicranium; upper jaw can be elevated relative to the basicranium (and is thus clear of the water surface during skimming); jaws capable of extremely rapid closure.

Hypothesis 5: azhdarchids were surface gleaners, or dippers, flying low over water and grasping food from the water surface (like albatrosses or frigate birds).
Predictions: no need for proficient terrestrial abilities (hind limbs may even be strongly reduced); highly developed soaring or gliding skills; jaws elongate with down-curved tips; flexible neck allowing the animal to reach down and behind itself as it picks up food while flying over the water.

Hypothesis 6: azhdarchids were stork-like generalists, picking up assorted invertebrate and vertebrate prey from shallow water and/or terrestrial environments.
Predictions: proficient terrestrial abilities; no need for highly developed soaring or gliding skills; bill elongate but lacking specializations (such as lateral or dorsoventral compression, keels, or hooked bill tips); neck flexibility not required as the neck only needs to bring the bill tips close to the ground; head-neck joint, at least, should be flexible.

The morphological evidence

Let’s now see how the morphological data matches with these hypotheses and their predictions. Firstly, despite all those early claims making out that azhdarchids were like immense vultures, with tremendously elongate wings indicative of superb soaring or gliding skills, we now know that this was just not true. In fact, their legs were proportionally long, their wings were proportionally short compared to those of other large pterosaurs, and preserved wing membranes (which reveal that the brachiopatagium attached to the ankle) show that their wing membranes actually made their wings proportionally broad, and with low aspect ratios. As Frey et al. (2003) concluded, azhdarchids exhibited poor gliding performance compared with other large pterosaurs. Prieto’s (1998) proposal that azhdarchid legs formed a pseudo ‘forked tail’ is nonsense given that the brachiopatagia incorporated the legs into the wings: they didn’t trail behind the body as do a bird’s tail feathers.

In terms of terrestrial abilities, we should note first that pterodactyloids in general were quite capable quadrupeds, and there is little reason to regard them as clumsy or helpless when grounded. Sure, they couldn’t sprint at speeds equaling those of cursorial animals, but there is every indication that they were proficient walkers, more than capable of foraging quadrupedally on the ground or in shallow water. This is backed up by functional morphology, computer modelling, and evidence from trackways. With their proportionally short wings, long legs with robust femora, and large, robust feet (Bennett 2001), azhdarchids were likely to have been even better suited for terrestrial foraging than most other pterodactyloids. These lines of evidence suggest that azhdarchids were not specialized for a life on the wing (contra Prieto 1998): rather, they were better on the ground than were most other pterosaurs.

What does skull anatomy suggest? Good azhdarchid skulls are few and far between, with the best one being the incomplete rostrum described by Kellner & Langston (1996). In basic terms, the rostrum is shaped like a very long scalene triangle: it’s deepest at the level of the nasoantorbital fenestra, but gradually tapers rostrally to a point. Some kind of bony crest is present over the caudal part of the nasoantorbital fenestra. Ignoring the crest, which living animals have a rostrum shaped like this? Storks, and not much else. Apparently the specimen described by Kellner & Langston (1996) is squashed flat, however, which makes it impossible to confirm whether the snout had the subrounded cross-sectional shape seen in storks. This is the spanner in the works, because if the skull is strongly compressed laterally, then the skull really isn’t stork-like at all, but probably suited for some other, quite different mode of life. Like skimming.

But hold on: this isn’t the only azhdarchid skull fragment known. Firstly, there’s Zhejiangopterus. Again, we have a pointed, elongate, overall stork-like rostrum, but again the only figured specimen is apparently squashed flat, so it’s not much use here. Aha, but there’s Azhdarcho. Its rostrum fragments clearly belonged to a long, pointed (cough - stork-like - cough) rostrum that would have been subtriangular in cross-section, with the flat palate forming the triangle’s base (Nesov 1984). An incomplete three-dimensional rostrum from Morocco, identified as ‘?Azhdarchidae’, was described by Wellnhofer & Buffetaut (1999). It most certainly is not strongly compressed laterally, but is instead like a broad-based triangle in cross-section. Finally, a complete mandible is known for the Hungarian azhdarchid Bakonydraco. It’s pretty odd, being pointed at its tip, slightly concave dorsally at the symphysis, and with a ventral mid-line ridge. The ridge is ventrally rounded, and not keel-like (Ősi et al. 2005). So, again, it's not laterally compressed.

Evaluation of the hypotheses

On the basis of all these features, how do the various hypotheses hold up?

Hypothesis 1 (the idea that azhdarchids were vulture- or marabou-like scavengers) doesn’t stand up too well: while it’s been all but rejected by some workers, note that they’ve only had scavenging raptors in mind, and haven’t thought of comparing azhdarchids with marabou storks or scavenging corvids. In contrast to scavenging raptors, corvids and marabous, the azhdarchid rostrum does not appear to have been well braced around its openings (this is the naris in the birds, but the nasoantorbital fenestra in the azhdarchids), nor (with its bony dorsal crest) is the skull well suited for probing into body cavities, nor is the long, stiff neck in agreement with this lifestyle. Finally, while proficient terrestrial abilities were present, it does not seem that azhdarchids were specialized for long-distance soaring flight, as obligate scavengers are. I therefore feel that Hypothesis 1 can be rejected. In fact, even facultative scavenging like that present in marabous seems unlikely for azhdarchids, as (unlike marabous) their bills were weakly braced around the bony openings.

There are no cranial specializations consistent with Hypothesis 2 (mud-probing). Azhdarchid bill tips most certainly lack the sensory pits that house Herbst corpuscles in birds, though whether these would be present in a mud-probing pterosaur anyway is a good question. Regardless, the long, stiff azhdarchid neck doesn't match what is predicted for mud-probers either, and this hypothesis must also be rejected. Hypothesis 3 (spear-fishing) can also be rejected given that it is hard to imagine how the long, stiff neck could permit rapid lunging, stabbing and/or grabbing, plus the bill tip morphology is not spear-like as it is in the birds that practice this lifestyle.

We next come to the most popular Hypothesis: number 3, the skimming one. Despite its popularity I have to say that this is weak and not supported by the morphological evidence. While azhdarchids may well have been skilled at fast, level flight (as is Rynchops), this lifestyle does not explain the probably proficient terrestrial abilities present in azhdarchids. More importantly, there is nothing in the azhdarchid skull showing that it was streamlined and laterally compressed as required for this hypothesis, nor is there any indication that the jaw joint or back of the skull was built to withstand jarring impacts, nor that the upper jaw could be elevated relative to water level, nor that the jaws were capable of rapid closure, as is the case in Rynchops (Tomkins 1951, Bock 1960, 1964, Zusi 1962). The predictions are not fulfilled, so the skimming hypothesis is rejected.

Or, at least, the hypothesis that azhdarchids were obligate skimmers is rejected. Tomkins (1963) wrote of his surprise on learning that Royal terns Thalasseus maximus and Caspian terns Hydroprogne caspia are both capable of skimming behaviour, even though they lack the many unusual features present in Rynchops. Might azhdarchids, also, have been facultative skimmers? I would say that we can’t rule it out, but (1) there’s no evidence in its support and it’s therefore nothing more than a speculation, and (2) it’s still less well supported than other hypotheses.

We can also reject the rather similar Hypothesis 5: that azhdarchids were albatross-like surface gleaners, picking up prey from the water surface. The birds that do this are specialized for gliding and lack proficient terrestrial abilities, they have to have a flexible neck as they need to reach down and behind themselves as they pick up prey from the water surface, and they all have down-curved bill tips, presumably to aid in grabbing prey.

Finally, there’s Hypothesis 6: that azhdarchids were stork-like generalists, picking up assorted invertebrate and vertebrate prey from shallow water and/or terrestrial environments. So far as I can tell, this is the only hypothesis where all of the predictions are met. Azhdarchids have the proficient terrestrial abilities required for a stork-like lifestyle, and lack features indicating a dedicated aerial lifestyle. Their jaws are elongate but lack the specializations present in skimmers, mud-probers or surface gleaners, and their long, straight neck vertebrae indicate that they could only raise and lower the neck vertically. That’s ok for picking up animals from the ground and/or the water, but not much else. I therefore find Hypothesis 6 to be the only one that matches the evidence.


So having completed this little exercise I still regard the skimming hypothesis as poorly founded and problematic, and I remain very much in favour of the stork hypothesis. It should be noted that azhdarchids lack the specializations seen in some stork taxa. Mycteria (wood storks), for example, has a gently down-curved bill, a particularly dense array of Herbst corpuscles, and muscles that allow the jaws to be closed within 25 milliseconds (one of the fastest reflexes among vertebrates). These features are used by the birds as they search - using touch alone - for submerged prey (Hancock 1985). Anastomus, the Open-billed stork, has scopate tomial edges (meaning that it possesses tiny brush-like structures along the margins of its bill) and upper and lower jaws that bow away from each other, meaning that their edges never meet. These are apparently specializations that assist in the holding of hard-shelled prey (Gosner 1993). Rather, azhdarchids seem most like the most generalized storks, such as the Ciconia species. These eat everything from large insects, to frogs, fish, small crocodilians and mammals, and they patrol marshy areas and flooded meadows as well as dry grasslands for such prey. In fact they can make a living just about everywhere, and if you wanted to you could draw another parallel with azhdarchids here.

More research on this area is needed, but having said that I realize I’ve pretty much just written the better part of a paper on the subject. At some stage I’ll re-vamp it for publication… perhaps with Mark as co-author. And on that note, the illustration above is Mark’s, and I use it here with permission. It can be seen in its original context here.

Yes yes, phd thesis, blah blah blah. It will be done by the end of this month, honest. For the latest news on Tetrapod Zoology do go here.

Refs - -

Arthur, S. C. 1921. The feeding habits of the Black skimmer. The Auk 38, 566-574.

Bennett, S. C. 2001. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part II. Size and functional morphology. Palaeontographica Abteilung A 260, 113-153.

Bock, W. J. 1960. Secondary articulation of the avian mandible. The Auk 77, 19-55.

- . 1964. Kinetics of the avian skull. Journal of Morphology 114, 1-42.

Frey, E., Buchy, M.-C. & Martill, D. M. 2003. Middle- and bottom-decker Cretaceous pterosaurs: unique designs in active flying vertebrates. In Buffetaut, E. & Mazin, J.-M. (eds) Evolution and Palaeobiology of Pterosaurs. Geological Society Special Publication 217. The Geological Society of London, pp. 267-274.

Gerritsen, A. F. C. & Meijboom, A. 1986. The role of touch in prey density estimation by Calidris alba. Netherlands Journal of Zoology 36, 530-562.

Gosner, K. L. 1993. Scopate tomia: an adaptation for handling hard-shelled prey? Wilson Bulletin 105, 316-324.

Halstead, B. 1989. Dinosaurs and Prehistoric Life. Wm Collins Sons & Co., Glasgow.

Hancock, J. 1985. Storks and spoonbills. In Perrins, C. M. & Middleton, A. L. A. (eds) The Encyclopedia of Birds. Guild Publishing (London), pp. 72-81.

Kellner, A. W. A. & Langston, W. 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas. Journal of Vertebrate Paleontology 16, 222-231.

Langston, W. 1981. Pterosaurs. Scientific American 244 (2), 92-102.

Lawson, D. A. 1975. Pterosaur from the latest Cretaceous of west Texas: discovery of the largest flying creature. Science 187, 947-948.

Lehman, T. M. & Langston, W. 1996. Habitat and behavior of Quetzalcoatlus: paleoenvironmental reconstruction of the Javelina Formation (Upper Cretaceous), Big Bend National Park, Texas. Journal of Vertebrate Paleontology 16 (Suppl. 3), 48A.

Nebel, S., Jackson, D. L. & Elner, R. W. 2005. Functional association of bill morphology and foraging behaviour in calidrid sandpipers. Animal Biology 55, 235-243.

Nesov, L. A. 1984. Upper Cretaceous pterosaurs and birds from central Asia. Paleontology Journal 1984 (1), 38-49.

Ősi, A., Weishampel, D. B. & Jianu, C. M. 2005. First evidence of azhdarchid pterosaurs from the Late Cretaceous of Hungary. Acta Palaeontologica Polonica 50, 777-787.

Padian, K. 1988. The flight of pterosaurs. Natural History 97 (12), 58-65.

Paul, G. S. 1987a. The science and art of restoring the life appearance of dinosaurs and their relatives - a rigorous how-to guide. In Czerkas, S. J. & Olson, E. C. (eds) Dinosaurs Past and Present Vol. II. Natural History Museum of Los Angeles County/University of Washington Press (Seattle and London), pp. 4-49.

- . 1987b. Pterodactyl habits - real and radio-controlled. Nature 328, 481.

Piersma, T., van Aelst, R., Kurk, K., Berkhoudt, H. & Maas, L. R. M. 1998. A new pressure sensory mechanism for prey detection in birds: the use of principles of seabed dynamics? Proceedings of the Royal Society of London B 265, 1377-1383.

Tomkins, I. T. 1951. Method of feeding of the Black skimmer Rynchops nigra. The Auk 68, 236-239.

Tomkins, I. T. 1963. Skimmer-like behavior in the Royal and Caspian terns. The Auk 80, 549.

Unwin, D. M., Bakhurina, N. N., Lockley, M. G., Manabe, M. & Lu, J. 1997. Pterosaurs from Asia. Journal of the Paleontological Society of Korea, Special Publication 2, 43-65.

Wellnhofer, P. & Buffetaut, E. 1999. Pterosaur remains from the Cretaceous of Morocco. Paläontologische Zeitschrift 73, 133-142.

Witmer, L. M. & Rose, K. D. 1991. Biomechanics of the jaw apparatus of the gigantic Eocene bird Diatryma: implications for diet and mode of life. Paleobiology 17, 95-120

Zusi, R. 1962. Structural adaptations of the head and neck in the black skimmer Rynchops nigra Linneaus. Publications of the Nuttall Ornithological Club 3, 1-101.

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Saturday, April 01, 2006

The Fifth Symposium on the Flying Humanoid Problem

I’ve just returned from the 5th Symposium on the Flying Humanoid Problem, this year held at Point Pleasant, West Virginia.

In contrast to some of the previous symposia, it was good to see that most of the problem areas are now agreed on, and that a new, integrated picture is coming together. Certainly one of the impressions I got from the talks was that most of the key researchers are working with one another, and certainly aren’t at loggerheads. That’s a long way off from the rather aggressive first and second meetings.

Anyway, one main area of disagreement does remain, and in fact proved quite controversial: what should these meetings be called? At the third meeting it was agreed that the term ‘flying humanoid’ would be scrapped, and that McEwan’s term, keelivolians, would be used instead. In an open-floor discussion held at the end of the first day, the organizers explained that they hadn’t done this, simply because few zoologists outside of keelivolian research would know what a keelivolian is. That’s fair enough, but I think they missed the point in that the only workers who attend these meeting are those involved in keelivolian research anyway! Next year’s meeting is to hosted by the Trois Freres group (France) and they’ve already announced that they will be using the term keelivolian in all of their promotion and literature. Good.

On to the actual presentations. Tuesday morning kicked off with fossils and phylogeny, with some functional morphology and anatomy in the afternoon. Wednesday was mostly devoted to historical biogeography, but with behavioral observations after lunch. Finally, Thursday was devoted to conservation and management, but I couldn’t stay for that day so missed those talks. If anyone caught them and can give me the details it would be appreciated.

After a brief welcome talk by McEwan and Jacques, Russell Hoban gave a talk entitled ‘New fossil keelivolians: finally, keelivolian phylogeny takes off’ (groan). Megaseptetoile is a new taxon from Pliocene France. It would have looked much like Septetoile but with proportionally longer limbs, plus overall it was much larger, with a wingspan of c. 3 m (compared to 1.5 m for Septetoile). Bretonia ornicephala is a new name for the population that used to be regarded as European Miocene representatives of Teenteea – actually, it isn’t like Teenteea at all, being smaller, with hindlimbs suggestive of semi-cursoriality (!) and with evidence for display structures on the back of the neck. A new phylogeny incorporating these taxa found mawnans Septetoile shielsi and Teenteea to be sister-taxa (which is consistent with Hall’s studies on trans-Atlantic movements: see below). The endemic west African taxa Kikiyaon and Guiafairo grouped as sister-taxa but, surprisingly, Sasabonsam proved closest to the Septetoile clade. The morphological evidence for this is actually pretty good, and the genetic data clearly favours it. Bretonia grouped in a clade with Tengusia and Danangia, the most basal member of which was Popobawa, which of course is African. There’s a strong African signal in the tree, with evidence for one Asian radiation, and for several independent invasions of Europe.

Hank Emerson presented new mtDNA work on mawnans, incorporating both living individuals and data from archaeological samples. While all sampled living individuals were closely related enough to imply recent divergence from a post-Pleistocene ancestor, the genetic diversity of the old specimens was big enough to show that a bottlenecking had occurred. What’s nice about this is that Hoban had previously suggested that this might be likely, given the tiny Cornish range of extant mawnans. However, brown mawnans proved distinct enough from grey mawnans to be raised to species level: they aren’t just brown-phase oddities as previously assumed, and the oldest available name for them is Septetoile reichenbachi Ernst 1939. While this increases the diversity of extant keelivolians, it’s disturbing from the conservationist perspective as brown mawnans are only known from two individuals and must be critically endangered. A pied mawnan reported and sampled in 1992 proved to be an aberrant grey mawnan.

Further evidence that mawnans were more widely distributed in Europe than they are today was presented by Henrietta Breuille who reviewed archaeological data from France, Austria and the Czech Republic. Cave paintings from France clearly depict Septetoile.

Don Worley continued on the same theme by showing how old eyewitness accounts of the SE Asian taxon Danangia come from places where the tropical forest matched that of the Vietnamese reserve where the last Danangia population survives. By implication, Danangia was formerly present in these other regions, and thus more widely distributed across SE Asia in the recent past. However, given the discovery of multiple new large tetrapods from Laos and Vietnam in recent years Worley considered it at least possible that Danangia might await rediscovery in some of these regions. A good question was asked after his talk: are all specimens of Danangia melanistic, and are they all female? The answer seems to be yes, so Danangia is presumed to be parthenogenetic, and thus unique among the group.

Brian Kerns and David Fetty discussed their study on a newly discovered skull of the North American taxon Teenteea keganpaulorum. Several areas of cranial morphology in Teenteea have remained unreported, so this was pretty welcome. The jaws are entirely edentulous and the tightly coiled cochlear canal indicates specialized high-frequency hearing. What I liked best about this presentation was that, though they didn’t really mention it, the data from the anatomy matches entirely with the postures and movements reported in field studies (Scarberry & Mallette 1966, Yoder & Enoch 1966). The morphology of the three occipital condyles, for example, indicates that the head can be rotated on the cylindrical atlas-axis complex by about 360º, which obviously way surpasses that of any other tetrapod. Even stranger, a strong S-shaped flexure in the cervical series (not obvious in live animals because of pectoral air sacs) means that the anterior part of the neck can be rapidly retracted into the thorax. This contention is supported by high-speed photography and shows that reports of rapid head retraction ‘into the shoulders’ by eyewitnesses were accurate.

Simon Parker discussed new field observations of mawnans (including the first day-time records of active individuals) and Mike Hall presented preliminary data from his behavioural studies on the Cornish mawnan population. Despite their localized range, hardly any other previous studies have covered this area (the two exceptions being Chapman & Perry 1976 and Opie 1978), mostly because the animals prove so cryptic whenever anyone tries to find them in the field. Looking mostly at long-distance movement and the cryptic behaviour, and using radio tagging and remotely-operated cameras, he has confirmed that mawnans spend literally weeks lying still on the forest floor, imitating logs. It is inferred that they avoid muscle wasting the same manner that hibernating mammals do, though this must remain speculative until more work is done. The hypothesis that mawnans might migrate across the North Atlantic has been confirmed by radio tracking of a tagged individual. Rather than migrating annually, as Hall previously proposed, the four tagged individuals each crossed the ocean between 6 and 9 times a year. Quite why they do this remains totally unknown.

All in all it was a great meeting (photo of all the speakers above, with me sneaking in at the far left). I didn’t get to go on the field trip, but I’ve seen the Teenteea roost sites before. Given that keelivolians were only recognized as a valid group of tetrapods in 1966 (Keel 1966), our understanding has come on leaps and bounds, and no doubt next year’s meeting will be as full of suprises. An abstract volume resulted from the meeting, and at least some of the presentations will appear in a special issue of Domrama.

PS - for the latest news on Tetrapod Zoology do go here.

Refs - -

Chapman, B. & Perry, S. 1976. Field tracking of the Mawnan, the first discovery of day-time terrestrial roost sites. Forest Ecology in Cornwall 34, 287-298.

Keel, I. 1966. A new, highly unusual group of enigmatic bipedal flying vertebrates. Science 153, 999-1000.

Opie, K. 1978. Observations on sleeping and roosting in mawnans, and the first attempt to capture nocturnal flight behaviour on film. Journal of Wildlife Management 5, 8775-8776.

Scarberry & Mallette 1966. Behavior in the field and laboratory of the new volant tetrapod Teenteea keganpaulorum Keel. Ethology 101, 373-395.

Yoder, P. & Enoch, B. 1966. Behavioral significance of vocalizations and high-speed flight in the North American flying humanoid Teenteea. American Journal of Animal Behavior 23, 67-80.