Vegetation-dwelling Dragons, group 1 (The Interlopers)

In his book "Biology and Evolution of Australian Lizards", Allen Greer sorted the lizards I study, the genus Ctenophorus, into different groups based on where they live: those that live in burrows, those that live in rock crevices, and those that live in vegetation. Looking at the phylogenetic relatedness of the Ctenophorus dragons, there are two groups of each: two groups of burrowers, two groups of rock-dwellers, and two groups of vegetation-dwellers. I thought it'd be fun to put up pictures and descriptions of all these groups, since I have a large pile of pictures from my fieldwork. Here is my first post, on the first group of rock-dwellers. Here is my second, on the first group of burrowers.

There is one group of dragons in Australia that, despite being small and unobtrusive, have been subjected to a pretty convoluted taxonomic history, mostly in the last thirty years. At one time or another, they were placed in four different genera of Australian dragon. They've been divided amongst different dragon genera. They've been split, lumped and resplit differently. They've been one species, two species, two species each with two sub-species, and four species. Currently, and conclusively, they are part of the genus Ctenophorus, the genus of dragons I have spent my PhD studying. These are what I've referred to as "the interlopers" because they are Ctenophorus without really acting like Ctenophorus. I wasn't going to say anything about them, but their taxonomic history is just so ridiculous I decided to dive into it. Each paragraph is titled based on new taxon or taxa discussed in the paragraph. 

Amphibolurus muricatus adelaidensis

The first of these dragons to be described was, unsurprisingly, the species that lives around Perth and Adelaide (rather than the species that live in the desert in the middle of nowhere). The very first record of these critters in the scientific literature is in a report George Grey (Gray? spelling is mixed, sometimes even in the same paper!) sent to the British Annals of Natural History in 1840. Grey described them as a variant (what we would now call a subspecies) of the jacky dragon (Amphibolurus muricatus), a resident of eastern Australia. Amphibolurus muricatus adelaidensis was originally described as "inhabits Western Australia, Adelaide". Ironically, the animals that live close to Adelaide are no longer members of the species adelaidensis, which is now restricted to the west coast of Australia, around Perth.* But we'll get to that.

*Species names are weird. Antaresia perthensis, a species of python, isn't found anywhere near Perth.

Amphibolurus adelaidensis

In 1885, the great George Boulenger was cataloguing the specimens held in the British Museum, including the specimens Grey had brought back from Australia.  It was Boulenger who gave Amphibolurus adelaidensis full species status, splitting it from the jacky dragon. He listed their range as "South Australia". In reality, what Boulenger was calling Amphibolurus adelaidensis lives across a lot more territory in Western Australia than South Australia. It lives along the west coast of the continent, including around Perth, and along the south coast of Australia from the southwest corner almost all the way to Adelaide. The name stuck for a while after that, and so it was just Amphibolurus adelaidensis for a good 80 years, until 1964.

Tympanocryptis parviceps

In 1964 the second species in this group was described. A year before becoming the Curator of Herpetology and Ornithology at the Museum of Western Australia, Glen Storr described a curious little lizard from Ningaloo on the mid-west coast of Australia. It had a partially covered tympanum, which is the external part of the lizard ear. Because of this, Storr classified as it as a member of the Tympanocryptis (genus name self-explanatory). Tympanocryptis are adorable little desert-dwelling pebble-mimics. Scare the crap out of them and they just duck down, curl their tail around, and hope you can't tell the lizard from the pebbles. Despite placing this new species of lizard in Tympanocryptis, Storr noted at the time that his new species was very similar to Amphibolurus adelaidensis and might prove to be more closely related to Amphibolurus adelaidensis than to the Tympanocryptis.

Amphibolurus parviceps butleri and Amphibolurus adelaidensis chapmani

In 1977 Storr revisited these dragons. In one fell swoop, he moved Tympanocryptis parviceps into Amphibolurus and described two new subspecies, one for parviceps and one for adelaidensis. The new subspecies of parviceps, A. p. butleri, "bridged the [morphological] gap" between parviceps and adelaidensis, convincing Storr that parviceps was more closely related to adelaidensis than to the Tympanocryptis. Amphibolurus parviceps parviceps (Storr 1964) is found the furthest north, from Dirk Hartog Island in the south to Exmouth in the north. From Shark Bay south to Kilbarri you get Amphibolurus parviceps butleri (Storr 1977). Then from Kilbarri to Perth is the territory of Amphibolurus adelaidensis adelaidensis (Boulenger 1885). Along the south coast of Australia, from Albany to the tip of the Yorke Peninsula, is where the fourth taxon, Amphibolurus adelaidensis chapmani (Storr 1977), lives. So now we have the four taxa of this group, three on the west coast of Australia and one on the south coast. That there are four taxa of dragon in this group, and that they are distributed like this, is never again contested. The only thing that kept changing from 1977 onwards was what people thought these four taxa should be called.

Rankinia adelaidensis, Rankinia chapmani and Tympanocryptis butleri

Up to now, all the taxonomic changes I've described are pretty standard stuff. In biology, as we get better at figuring out what the tree of life looks like and how the different branches are connected, taxonomy changes to reflect our improved understanding of the world around us and the animals in it. This generally makes things clearer for biologists. Sometimes, however, taxonomic trolls come along and make everything more opaque and confusing.

In 1984 Wells & Wellington threw a real spanner in the works (Australian expression) by self-publishing a non-peer reviewed paper, which was essentially a glorified list of all the species of reptile in Australia. They "started" their own journal in order to publish it, and to date these lists are the only thing the "journal" has ever published. The major problem with this list of Australian reptiles is that they decided to use it to describe a whole bunch of new species. They described them very very poorly, to the point that it's nigh-on impossible, if you have an animal in hand, to tell what species Wells & Wellington think that animal belongs to. This kind of crap is often referred to as taxonomic vandalism and, for whatever reason, Australian reptiles seem to be its greatest victims. Here is an excellent rundown of this problem from the scientific literature, and here is an equally excellent one in the popular literature.

One thing Wells & Wellington did was invent the genus Rankinia based on, as far as I can tell, almost nothing. They elevated chapmani to species level, based on actually nothing. Literally, all they say is "Rankinia chapmani (Storr, 1977): Herein formally elevated to specific status; confined to the western Nullarbor Plain."*  They did a similar thing with Tympanocryptis butleri, which, less than ten years earlier, in a paper Wells & Wellington cite, was moved into Amphibolurus. So Wells & Wellington moved butleri and parviceps back into Tympanocryptis without any justification, elevated butleri and chapmani to species status without any justification, and invented the genus Rankinia for adelaidensis and chapmani for no good reason.

*Side note: What Wells & Wellington call Rankinia chapmani is not confined to the western Nullarbor plain. It's found from Albany in Western Australia to the tip of the Yorke Peninsula in South Australia.

Rankinia butleri and Rankinia parviceps

In 1985, Wells & Wellington self-published another non-peer reviewed glorified list, this time of the reptiles and amphibians of Australia. In this new list they put butleri and parviceps in their invented genus Rankinia. The most impressively ballsy part of this is that they don't even point it out. They make absolutely no attempt to indicate that they've moved these species, let alone some kind of justification for it. Moving species from one genus to another usually involves entire papers worth of justification.

Various combinations of AmphibolurusRankinia and Tympanocryptis with adelaidensis, butleri, chapmani and parviceps

What followed is 20 years of chaos. These lizards are rather obscure, that goodness, so as far as I can tell there hasn't been a large body of scientific literature published on these species. Part of the problem of taxonomic vandalism is that is makes it very difficult to do thorough literature searches. You can never be sure you've seen all the papers on your creature of interest as maybe someone has published something relevant using a different taxonomy.

I tried to figure out what, if anything, had been published in the scientific literature since Wells & Wellington. I did literature searches for just the species names (i.e. no genera) and various words I thought were relevant, such as "agamidae" "lizard" or "Australia". For example, I did searches for "parviceps Agamidae" and "chapmani Australia". I wasn't able to come up with much. Most of what I found were biodiversity surveys that turned up one of the four taxon. The papers I did turn up used a mixture of genera for the different species, as well as referring to butleri and chapmani as subspecies or species.

Perhaps a better example of the chaos is the variation in taxonomy used by the highly respected experts who have published books on Australian reptiles and amphibians since Wells & Wellington. The 1983 edition Reptiles and Amphibians of Australia by Harold Cogger uses Amphibolurus adelaidensis and Tympanocryptis parviceps and doesn't list subspecies. The 2000 edition of the same book uses Tympanocryptis  for both adelaidensis and parviceps  and lists both butleri and chapmani as subspecies. The Biology & Evolution of Australian Lizards by Allen Greer (1989) uses Rankinia adelaidensis, Rankinia chapmani, Tympanocryptis butleri and Tympanocryptis parviceps. A Complete Guide to Reptiles of Australia by Steve Wilson & Gerry Swan, published in 2003, uses Rankinia for both adelaidensis and parviceps and lists butleri and chapmani as subspecies.

Ctenophorus adelaidensis and Ctenophorus chapmani

Finally, along comes the hero of our story. In 2001, Jane Melville & colleagues published a study that used the Ctenophorus phylogeny to look at ecological diversification in agamid lizards in Australia. A small side-result of the project was the discovery (which appears to be rather unexpected, though it's hard to tell from dry scientific literature) that what Jane et al. call Rankinia adelaidensis is actually a Ctenophorus. So these lizards didn't belong in any of the three genera that they kept being bounced between, but in a genus nobody predicted! Based on this result, Melville et al. suggest moving adelaidensis and chapmani into Ctenophorus.

Ctenophorus butleri and Ctenophorus parviceps

In 2008, this whole ugly mess was finally put to bed. Jane Melville & colleagues published a thorough analysis of the genetics and morphology of all four taxa. They show that each taxa is its own species and that the four species belong in the genus Ctenophorus. So now we have Ctenophorus adelaidensis, Ctenophorus butleri, Ctenophorus chapmani and Ctenophorus parviceps. Whew.

Originally I intended to not say anything about these lizards, and yet I seem to have said more about them than any other thing here. Despite being members of the Ctenophorus they are not part of my PhD. Which is lucky, because they're apparently not that easy to find. We were within range of Ctenophorus chapmani for a week in October 2013 and we didn't see a single one. That's despite spending the entire time looking for small, ground-dwelling dragons. Oh well. My next post will have more pictures and fewer words, promise.