Tetrapod Zoology

Richard Dawkins and the crappy 'humanoid dinosaurs' that just won't die

Wed, 11 Nov 2009 07:02:00 -0500

Regular readers will know that I'm not exactly a fan of the idea - discussed here and there in the technical (Russell & Séguin 1982, Russell 1987), popular (Hecht 2007, Socha 2008, Naish 2008) and speculative literature (McLoughlin 1984, Magee 1993) - that non-avian theropod dinosaurs might have evolved into humanoids had they not bought the farm 65 million years ago [image below by Matt Collins].

The hypothetical (emphasis: hypothetical) evolution of big brains, intelligence and so on among imaginary post-Cretaceous deinonychosaurs is not (in my opinion) all that unreasonable, and I base this assertion on what birds have been doing over the past 65 million years. Look at parrots and corvids. Parrots overlap with primates in brain : body size ratio, intelligence and abilities, and evidence suggests that they (and corvids) have sophisticated emotions that aren't much different from ours (or from those of other primates; humans are not magic animals different from all the others, but part of a spectrum). You probably heard the recent reports about funeral rites in magpies. This was in the news thanks to the publication of Bekoff's paper (Bekoff 2009), but stuff like this has been widely reported anecdotally and there's every reason to take it seriously [Alex the grey parrot (1976-2007) shown below, from wikipedia].

Read the rest of this post... | Read the comments on this post...

The Tet Zoo tour of Libya (part II): of larks and buntings

Tue, 10 Nov 2009 07:51:00 -0500

After a little delay, I'd like to continue regaling you with, if I may, my assorted musings on my excursion to the Great Socialist People's Libyan Arab Jamahiriya. In other words, I want to talk more about Libya...

Read the rest of this post... | Read the comments on this post...

Christmas cheer from... from... wtf?

Mon, 09 Nov 2009 04:30:00 -0500

My wife gives money to a cancer charity. She gets literature of some sort for doing this, and here's the front cover of the Christmas booklet she recently received. Why, as a Tet Zoo nerd, do I find it so funny?

Read the comments on this post...

Won't someone please think of the coelacanths, and other lamentations

Thu, 05 Nov 2009 08:23:05 -0500

Goddammit, no time for more reports from Libya, or for more in the toads series, or for articles on hairless Spectacled bears or tiny heterodontosaurids or neovenatorids, or anything really. Here's how things are progressing in view of Saturday's event...

Read the rest of this post... | Read the comments on this post...

The Tet Zoo tour of Libya (part I)

Tue, 03 Nov 2009 06:11:00 -0500

So, I recently returned from a brief sojourn in Libya. The trip was led by Richard Moody, best known for his work on Cretaceous sea turtles; I was also accompanied by palaeornithologist Gareth Dyke and by a group of people interested in the country's geology.

Libya - officially, the Great Socialist People's Libyan Arab Jamahiriya - is huge: it covers nearly 2 million square kilometres and is the fourth largest African county. However, 90% of the country is desert, and the population is only about 5.7 million (of which nearly 2 million live in Tripoli, the capital). It's a land of spectacular sweeping landscapes, enormous vistas, rocky hillsides, wadis and deserts. The landscape isn't all that different from the wilds of Morocco - the only other north African country I've visited - but the towns have a totally different feel, as Libya lacks the long tourist tradition of that country. Visitors thus get none of the constant hassling they get in places like Morocco. While the country runs on paperwork, with everything being stamped in triplicate, signed and counter-signed, there's no strong military presence or anything like that, and we never felt uneasy or uncomfortable. Huge pictures of Gaddafi are everywhere.

Read the rest of this post... | Read the comments on this post...

Sea Monsters, the CFI conference

Fri, 30 Oct 2009 10:10:21 -0500

On November 7th 2009, the Centre For Inquiry in London is hosting a one-day event titled Monsters From the Deep! It's being held at Conway Hall in Red Lion Square (a venue I know all too well...). I'm giving a talk at the event so wanted to advertise it: for more details please visit the CFI website here. The day kicks off at 11am and will include both talk and workshop sessions. Charles Paxton of the University of St. Andrews, well known for his work on statistical ecology, will be giving a talk titled 'Anecdotes, statistics and sea monsters'. The belief that anecdotal data (in this case, reports of sea monsters) can be dismissed wholesale is naïve, as analysis can still reveal meaningful inferences (make sure you see Paxton (2009) for more on this). Charles will also be leading a workshop on 'Ecology of aquatic monsters'. A very belated congrats to Charles, incidentally, for his 2002 Ig Nobel Prize for Bubier et al. (1998).

Read the rest of this post... | Read the comments on this post...

The Natterjack, its life and times

Wed, 28 Oct 2009 06:20:00 -0500

The Natterjack Epidalea calamita (introduced in the previous article) is a remarkable animal, well adapted for the dry, relatively saline environments it inhabits (there are places where Natterjacks inhabit saltmarshes, moors, and disused industrial areas). A proficient burrower, it starts digging a burrow with its forelimbs but does most of the work with its hindlimbs (hindlimb burrowing is typical for anurans, whereas forelimb burrowing is highly unusual). The burrows help the toads to gain access to moisture in dry habitats because they typically extend down to damp sediments; a particularly absorbent patch of granular skin on the animal's belly enables it to make the most of damp sediments when they're encountered [adjacent photo by kind courtesy of Neil Phillips].

Read the rest of this post... | Read the comments on this post...

Toads of the world: first, (some) toads of the north

Mon, 26 Oct 2009 09:20:00 -0500

If you've been following the toad series, you'll have read articles that introduce toads in general, discuss reproductive biology, and look at cranial anatomy. This can all be regarded as background introductory stuff. From hereon, we're mostly going to look at toad diversity in rough phylogenetic order: that is, starting at the base of the clade and working up to the 'top'of the tree [European common toad Bufo bufo shown here, from wikipedia. This individual has really weird nostrils].

Basal toads are all South American, and include the South American redbelly toads (Melanophryniscus) and the stumpfoot or harlequin toads (Atelopus). The South American Rhaebo toads (conventionally included within Bufo) also seem to be basal within the bufonid crown. The rest of toad phylogeny is rather controversial: some studies recover a major Old World clade that includes several Asian, African and Eurasian clades as well as a clade of New World toads including the Cane toad group (Rhinella) and North American group (Anaxyrus) (Pramuk et al. 2008). If this topology is correct, crown-toads - ancestrally South American - radiated extensively in the Old World but re-invaded the Americas during the Eocene. Others studies find Rhinella and so on to be outside of the Old World clade (Van Bocxlaer et al. 2009). We'll be coming back to the various details here later on.

Read the rest of this post... | Read the comments on this post...

Skulls, crests, snouts and giant poison glands: the heads of toads

Wed, 21 Oct 2009 08:03:00 -0500

Yes! MORE TOADS. You surely know what a toad's head looks like. But there's a lot about toad skulls that you almost certainly don't know, and the aim of this article is to review toad skull anatomy. This might seem like an arcane subject, but - as we'll see - the diversity of toad skulls is really quite remarkable and much of toad success can be put down to various of their cranial features (such as their parotoid glands and strong degree of cranial ossification)...

Read the rest of this post... | Read the comments on this post...

Our sex lives in words and pictures (or, On the reproductive biology of the Bufonidae)

Mon, 19 Oct 2009 04:51:00 -0500

After a brief hiatus we return to the remarkable world of toads, and this time round we look at reproductive biology. As a western European person, the toad species I'm most familiar with (the Common toad Bufo bufo and Natterjack Epidalea calamita [see later articles for details on the name changes]) are seasonal breeders that turn up at ponds early on in the year [Common toad mating ball shown here, photo by Neil Phillips] and produce strings of hundreds or thousands of eggs (between 400 and 7500). There are other toad species that are even more fecund, with individuals of some species (like the American toad Anaxyrus americanus and Cane toad Rhinella marina) producing more than 20,000 eggs on occasion: if you put an egg string from one of these species into a straight line, it would be up to 20 m long. You might think that no-one will ever see an egg string even approaching that length, given that the toads wind the strings around plants and debris. However, the egg strings of species that lay their eggs in streams or rivers sometimes become un-entangled by heavy rains and are then swept downstream: Shannon & Werler (1955) reported seeing a doomed string belonging to a Mountain toad Incilius cavifrons that was about 14 m long.

Read the rest of this post... | Read the comments on this post...

The sort of stuff I put on facebook

Sun, 18 Oct 2009 07:51:09 -0500

Preparing blog posts for Tet Zoo takes hours, sometimes days or even weeks. It's done in "spare time". Putting crap on facebook takes minutes and can be done during the course of a normal work day. Some of the stuff is soooo hilarious it deserves to be shared...

Francisco Gascó (aka Paco) knocked this up, thanks Paco. It was taken in about ~~1992~~ 1994 (when I was 18 19): note the Battat dinosaurs on the terrarium lid, Greg Paul theropods on the wall, and Luis Rey spiky amargasaur t-shirt. The croc skull is a juvenile C. niloticus.

Read the rest of this post... | Read the comments on this post...

It would appear that my other new book is out: Dorling Kindersley's Prehistoric

Fri, 16 Oct 2009 09:33:00 -0500

Regular readers will know that my new book, The Great Dinosaur Discoveries (A & C Black in UK; UCP in US), was released over the last few weeks. By all accounts, it's currently selling well and the reviews that have appeared so far have all been outstandingly positive [example]. Things are looking good. But I work hard, and over the last couple of weeks I've received the news that a second book I completed at about the same time is also now out. Today I received my copy, so can at last talk about it.

Read the rest of this post... | Read the comments on this post...

Darwinopterus, the remarkable transitional pterosaur

Wed, 14 Oct 2009 03:58:00 -0500

Pterosaurs - the charismatic flying archosaurs of the Mesozoic Era - fall fairly nearly into two great assemblages: the primitive, mostly long-tailed basal forms (or 'rhamphorhynchoids') and the more strongly modified, consistently short-tailed pterodactyloids. Pterodactyloids emerged in the Middle Jurassic and persisted to the very end of the Late Cretaceous, and fossils show that they did an awful lot more in their evolution than did non-pterodactyloid pterosaurs. Several lineages evolved giant size, and bizarrely specialised skulls and dentitions show that they took to filter-feeding, mollusc cracking, and perhaps to frugivory, carrion feeding and terrestrial stalking (Wellnhofer 1991, Wellnhofer & Kellner 1991, Unwin 2003, Witton & Naish 2008). A list of anatomical characters show that pterodactyloids are most closely related to the rhamphorhynchids (Kellner 2003, Unwin 2003) - a group of Jurassic non-pterodactyloid pterosaurs that have a relatively low number of needle-like teeth and are best known for Rhamphorhynchus from the German Solnhofen Limestone. While intermediates between rhamphorhynchids and pterodactyloids are hypothesised to have existed, they have remained unknown. Until now [image above shows Darwinopterus predating on small maniraptoran theropod: image by Mark Witton].

Read the rest of this post... | Read the comments on this post...

Bidder's organ and the holy quest for synapomorphies

Tue, 13 Oct 2009 05:35:00 -0500

One of the dirty little secrets of biology is that many groups of organisms have never been 'defined' in the phylogenetic sense: a group grows over time as people add new species to it, but they only do this because it 'feels' about right, not because there's any rigorous way of knowing whether those species really belong there or not. Many tetrapod groups - classic examples include Ranidae, Muscicapidae, Colubridae and Scincidae - lack characters that might allow their monophyly to be demonstrated, and modern studies show that various of their constituent members aren't more closely related to each other than they are to members of other groups. Some herpetologists argue that amphibians have been particularly affected by this sort of thing, given that their taxonomy and systematics have been (comparatively speaking) little studied, and that a form of social conservatism has often dominated decisions about taxonomy (Frost et al. 2006, p. 12). Despite the number of species involved, however, toads don't seem affected by this, in part because workers have often used what appears to be a synapomorphy when identifying an anuran as a toad: the presence of a Bidder's organ. Yes, here's another article on toads (aka bufonids) [adjacent image shows a few of the species conventionally lumped together within Bufo (from top to bottom): Common toad B. bufo (courtesy of Neil Phillips), Southern panther toad Amietophrynus pantherinus (from wikipedia), and Slender-legged toad Leptophryne borbonica (courtesy of John C. Murphy)].

Read the rest of this post... | Read the comments on this post...

Toadtastic - the invasion begins!

Mon, 12 Oct 2009 04:22:11 -0500

I forget how it started now, but lately I've been very, very interested in toads (yes, toads), so much so that I've felt compelled to write about them. The problem is that toads - properly called bufonids - are not a small group. On the contrary, this is a huge clade, distributed worldwide and containing about 540 species in about 38 genera (as of October 2009). So, there are a lot of species to write about, and covering all or most of them is quite the challenge. But it's the sort of challenge I like...

Read the rest of this post... | Read the comments on this post...