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Tetrapod Zoology

Tetrapod Zoology

Amphibians, reptiles, birds and mammals - living and extinct

Welcome to Tetrapod Zoology ver 3

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Hmm, how on earth do I start this article? How about… hello and welcome, new readers, to Tetrapod Zoology, a blog devoted to the diversity, biology, evolution and ecology of the tetrapods, the neatest animals of them all. To all you ‘old’ readers, welcome to Tet Zoo in its new home here at Scientific American. This is Tet Zoo ver 3. So, when I said over on Tet Zoo ver 2 that Tet Zoo was coming to an end, I was of course referring to Tet Zoo ver 2. Ver 2 – the ScienceBlogs-hosted version – had a good run (2007-2011), but it had to end. Onwards and upwards. [The adjacent image shows a sort of montage of some of the subjects that've been covered so far on Tet Zoo. A novel feature for me - it wasn't present over at ScienceBlogs - it that images here can be embiggened by clicking. So, no more being constrained to tiny, tiny images. Embiggen as required].

Me and what I do

So, my name’s Darren Naish. By day I currently work as a popular writer, consultant and technical editor (my experience, qualifications and expertise are very much centred around, err, tetrapods), but in ‘spare time’ I’m a researching palaeozoologist who publishes technical work on such fossil tetrapods as dinosaurs, pterosaurs and Mesozoic marine reptiles. I’ve co-named various new dinosaurs (Eotyrannus lengi, Mirischia asymmetrica and Xenoposeidon proneneukos), and I’ve participated in fieldwork at home and abroad [the adjacent image - of me - was taken during recent fieldwork in Romania]. For examples of my work available free, online, to anyone and everyone, please see Naish et al. (2004) on the giant Isle of Wight brachiosaur, Witton & Naish (2008) on the palaeobiology of azhdarchid pterosaurs, Taylor et al. (2009) on sauropod neck posture, and Taylor et al. (2011) on the 'necks for sex' debate.

I’ve written several books on dinosaurs and other fossil animals. The best of these is perhaps The Great Dinosaur Discoveries (Naish 2009), published by University of California Press [ver 2 blog article here]. Note that one of my books – Tetrapod Zoology Book One (Naish 2010a) [ver 2 blog article here] – is a compilation of articles from Tet Zoo ver 1. Over the years, I’ve worked on and off as a TV consultant and researcher: I get used fairly regularly as one of those ‘talking head’ experts, sometimes for good, sometimes for evil. I’m married and have kids, a mortgage and all that those things entail.

I also have vested academic interests in quite a few other areas of research (all related to the world of tetrapod zoology), including the phylogeny of modern birds, swimming behaviour in giraffes (no, really: see Henderson & Naish (2010) and Naish (2010b)), amphibian decline and conservation, plastic pollution, ecosystem degradation, re-wilding and academic cryptozoology. Since 2006, I’ve been writing about the world of tetrapod zoology, first at my old blogspot site (Tet Zoo ver 1), then at ScienceBlogs (Tet Zoo ver 2). I started blogging for no particular reason other than that it looked fun. So – what is Tet Zoo all about?

Tetrapod Zoology: it’s all about the tetrapod zoology

Tet Zoo – the blog you’re reading right now – is all about zoology, but specifically the branch of zoology dedicated to tetrapods. Hence… Tetrapod Zoology.

What are tetrapods? Tetrapods are the limbed vertebrates: the backboned animals that possess four limbs with digits, or those backboned animals that descend from ancestors that possessed four limbs with digits (snakes and dolphins are thus still tetrapods). So, it’s the amphibians, reptiles, birds and mammals [a highly simplified cladogram showing the affinities between tetrapods and other osteichthyan clades is shown here]. All of them, living and extinct. My aim at Tet Zoo has very much been to discuss and disseminate information on (sometimes obscure) tetrapod groups, and to increase awareness of them where appropriate.

Actually, there are two different meanings of the term ‘tetrapod’. The traditional one applies to all limbed vertebrates, right from the very first lobe-finned fish that had what could be regarded as limbs and digits (e.g., Ruta et al. 2003): this is a ‘total-group’ or ‘branch-based’ definition. A newer use of the term restricts it to the limbed vertebrate crown-group: that is, the clade that includes all living tetrapods and all descendants of their most recent common ancestor, but not limbed vertebrates as a whole (Laurin 1998, 2002, Laurin et al. 2000, Laurin & Anderson 2004). The authors who promote this latter use of the term suggest that we should use the term Stegocephalia or Stegocephali for the limbed vertebrate total-group. ‘Early tetrapods’ like the famous Ichthyostega [shown here; image by Nobu Tamura, from wikipedia] are non-tetrapod stegocephalians or stem-tetrapods under this definition, not tetrapods proper. My opinion on this debate is that the name Tetrapoda is best applied to the more inclusive clade traditionally associated with this name (‘proto-tetrapods’ like Tiktaalik have been regarded as outside of Tetrapoda, but part of a more inclusive clade termed Tetrapodomorpha (Daeschler et al. 2006). Within Tetrapodomorpha, the informal term ‘limbed tetrapodomorphs’ has been used for the Tiktaalik + Tetrapoda clade (Downs et al. 2008)). But we don’t have to worry much about this matter anyway, at least not at the moment.

I suppose there’s a third meaning for ‘tetrapod’, too: ‘any animal with four legs’. Some butterflies and maybe a few other creatures might be ‘tetrapods’ in this sense, but they’re not tetrapods proper.

Unsurprisingly, and (I hope) forgivably, I’ve been distracted on numerous occasions by big, sexy tetrapods like tyrant dinosaurs, sauropods [adjacent sauropod diagram from Taylor et al. (2011)], giant pterosaurs and giraffes and also by such things as the sex lives of ducks, but I’ve also made real efforts to cover obscure frogs, lizards, snakes, rodents, bats and other such animals. In fact, a regular theme at Tet Zoo has been the attempted review of whole groups of massively speciose, globally important yet little-discussed, rarely-synthesised groups such as vesper bats, gekkotan lizards and the toads of the world. It can take literally years to get through projects like that, and one of my greatest frustrations is that I haven’t been able to make more progress than I have. As I always say, there is still so much to do.

So, over the past year or so, I’ve been discussing such things as wrist- and wing-weapons borne by birds, bat diversity, stegosaurs, the biology and anatomy of the pygmy right whale, and the presence of peculiar pockets, pouches and sacs in the heads and necks of mammals. This is against a background of sea monster carcasses, giant salamanders, fossil African cattle, matamata turtles and a ton of other stuff [adjacent image shows a variety of matamata images.. no real reason, just because I can]. So – what’s to come, at least in the short term?

Actually, I increasingly try not to make promises like this any more, since I’m bad at keeping them for reasons stated above. But topics that should get coverage here soon include fossil rabbits, European frogs, frogmouths, bats of various sorts, Mesozoic birds, seabirds, fossil crocodilians, plesiosaurs and ichthyosaurs. And there are always plans to publish more on lizards, snakes, obscure dinosaurs and so on [adjacent image shows giant model of the Eurasian lacertid lizard Lacerta agilis, with the real thing below]. Non-mammalian synapsids also really need some coverage on Tet Zoo. Basically, if you’re interested in animals or natural history in general, or in tetrapods specifically, you should definitely hang around.

Tet Zoo has a facebook page where I post links and also add a little of what you might consider ‘supplementary material’: stand-alone bits of art and such that are relevant to the published articles. I’m also on Twitter where I tweet as TetZoo.

Seeing as this is the first article here at ver 3, I need to state a few basics. Tet Zoo ver 2 became well known not only for the content of its articles, but also for its talkative community of regular commenters. Hopefully, that will continue here - I encourage you all to comment regularly and not to be shy about making observations nor posing questions. Pseudonyms and anonymity are permitted to a degree. Personal attacks on other commenters are not permitted of course, nor is abusive or obnoxious behaviour. Bar spammers, I've only ever felt the need to ban one two commenters from Tet Zoo, and if you're aware of these individuals you'll know why I did so. I reserve the right to edit and quarantine comments as appropriate, though this only ever happens in exceptional circumstances. Tet Zoo is image-heavy and I'm always looking for more pictures, especially of obscure species: if you ever think you can help, do email me (needless to say, I aim to credit all sources and seek permission for image-use when required). I'm at eotyrannus at gmail dot com. On the subject of emails, I honestly try to respond to all the requests, questions and such I receive, but these days I just get too many emails to keep up with. Anyway, welcome to Tet Zoo ver 3. I hope you enjoy what I do and that you get into the habit of visiting on a regular basis.

Refs - -

Daeschler, E. B., Shubin, N. H. & Jenkins, F. A. 2006. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature 440, 757-763.

Downs, J. P., Daeschler, E. B., Jenkins, F. A. & Shubin, N. H. 2008. The cranial endoskeleton of Tiktaalik roseae. Nature 455, 925-929.

Henderson, D. M . & Naish, D. 2010. Predicting the buoyancy, equilibrium and potential swimming ability of giraffes by computational analysis. Journal of Theoretical Biology 265, 151-159.

Laurin, M. 1998. The importance of global parsimony and historical bias in understanding tetrapod evolution. Part I. Systematics, middle ear evolution and jaw suspsension. Annales des Sciences Naturelles 1, 1-42.

- . 2002. Tetrapod phylogeny, amphibian origins, and the definition of the name Tetrapoda. Systematic Biology 51, 364-369.

- . & Anderson, J. S. 2004. Meaning of the name Tetrapoda in the scientific literature: an exchange. Systematic Biology 53, 68-80.

- ., Girondot, M. & de Ricqlès, A. 2000. Early tetrapod evolution. Trends in Ecology & Evolution 15, 118-123.

Naish, D. 2009. The Great Dinosaur Discoveries. A & C Black, London.

- . 2010a. Tetrapod Zoology Book One. CFZ Press, Bideford.

- . 2010b. Will it float? Scientific American 304 (1), 22.

- ., Martill, D. M., Cooper, D. & Stevens, K. A. 2004. Europe's largest dinosaur? A giant brachiosaurid cervical vertebra from the Wessex Formation (Early Cretaceous) of southern England. Cretaceous Research 25, 787-795.

Ruta, M., Coates, M. I. & Quicke, D. L. J. 2003. Early tetrapod relationships revisited. Biological Reviews 78, 251-345.

Taylor, M. P., Hone, D. W. E., Wedel, M. J., & Naish, D. 2011. The long necks of sauropods did not evolve primarily through sexual selection Journal of Zoology : 10.1111/j.1469-7998.2011.00824.x

- ., Wedel, M. J. & Naish, D. 2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54, 213-220.

Witton, M. P. & Naish, D. 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS ONE 3 (5): e2271. doi:10.1371/journal.pone.0002271

The views expressed are those of the author and are not necessarily those of Scientific American.

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