The unusual fossil mammal skull posted here yesterday was, of course, that of the astrapotheriid astrapothere Astrapotherium magnum, as many as you said. But I'm a bit surprised that more people didn't get it straight away, given that astrapotheres were covered and covered again at Tet Zoo only a couple of months ago. However, I suppose that reading about something doesn't necessarily mean that you know how to identify its fossils... I'm still planning to post a write-up of the CEE Functional Anatomy meeting here ASAP, but haven't had time to finish it yet. Meanwhile...
... the modern animal shown above is an enigmatic British lizard, captured at Great Goswell Copse, Hampshire (southern England), by ecologist Dave Hubble. Dave took this photo in 1995. The lizard's colour is bizarre. It's a lacertid, and neither of our two native lacertids (Viviparous lizard Zootoca vivipara and Sand lizard Lacerta agilis) look at all like this. Yes, we have those (probably alien) Green lizards (L. bilineata... and perhaps L. trilineata too), but they look nothing like this either. And we have lots of Wall lizards Podarcis muralis too (go here for more), but they're entirely different as well (sharper snout, longer limbs etc.). The conclusion seems to be that this specimen is a freaky mutant Viviparous lizard, an identification supported by the animal's head scalation. You probably know of the Viviparous lizard as Lacerta vivipara: however, Mayer & Bischoff (1996) argued that the traditionally conceived version of this genus is horrendously paraphyletic and that multiple species must be removed and given their own (usually old) generic names. Indeed the rampant paraphyly of traditional 'Lacerta' has been quite widely recognised (e.g., Arnold 1989, Fu 1998, 2000). Zootoca isn't a new name, but was coined by Wagler in 1830. Mean to do more on European lacertids some time: some real surprises in there what with the evolution of giantism, herbivory, viviparity, and incipient adaptation to marine life, and don't forget the super-rapid morphological evolution just documented in an introduced colony of Podarcis sicula by Herrel et al. (2008)*. Thanks to Dave for use of the image.
* Within the space of 36 years, a colony introduced to a Croatian island have evolved herbivory and now have more voluminous guts than other P. sicula populations. The Croatian herbivores also have caecal valves - an anatomical novelty not present in other P. sicula populations and in fact rare in lizards as a whole - and a more robust cranial architecture than populations of the species elsewhere. Incidentally, this was not the lacertid population featured on Attenborough's Life in Cold Blood - those were P. lilfordi, and their recent evolutionary history is an altogether different (but no less astonishing) story (so far it's only been publish in abstracts and we have yet to see the full paper, to my knowledge).
Oh yeah - and am in the field this weekend in search of native reptiles. Will hopefully see Smooth snake Coronella austriaca, our only constricting colubrid. Yes - we have constricting snakes in Britain!
Refs - -
Arnold, E. N. 1989. Towards a phylogeny and biogeography of the Lacertidae: relationships within an Old-World family of lizards derived from morphology. Bulletin of British Museum of Natural History (Zoology) 55, 209-257.
Fu, J. 1998. Toward the phylogeny of the family Lacertidae: implications from mitochondrial DNA 12S and 16S gene sequences (Reptilia: Squamata). Molecular Phylogenetics and Evolution 9, 118-130.
- . 2000. Toward the phylogeny of the family Lacertidae - why 4708 base pairs of mtDNA sequences cannot draw the picture. Biological Journal of Linnean Society 71, 203-217.
Herrel, A., Huyghe, K., Vanhooydonck, B., Backeljau, T., Breugelmans, K., Grbac, I., Van Damme, R. & Irschick, D. J. 2008. Rapid large-scale evolutionary divergence in morphology and performance associated with exploitation of a different dietary resource. Proceedings of the National Academy of Sciences 105, 4792-4795.
Mayer, W. & Bischoff, W. 1996. Beiträge zur taxonomischen Revision der Gattung Lacerta (Reptilia: Lacertidae). Teil 1. Zootoca, Omanasaura, Timon und Tiera als eigenständige Gattungen. Salamandra 32, 163-170.
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I wonder if anybody knows hybrids between Viviparous and Sand or Green lizard?
BTW, changing Lacerta vivipara to Zootoca is a bit like changing definition of metre or kilogram. Any benefit for a few people interested in precise relationship between lacertid lizards is smaller than the confusion of the majority of nature lovers who memorized scientific names of common European animals.
We are in strange position, when scientific names, supposedly meant to be universal and easily recognizable, are more fluid than common names. People follow common names which became more constant than scientific names.
BTW A question - answer without checking Google: What is Cyanistes ombrosus? Have you ever seen this taxon?
Darren - do you know if it was only the colour that was unusual or whether there were any structural abnormalities to go with it?
But... the Astrapotherium skull is incomplete, isn't it?
That's because the binomen includes a hypothesis about the relationships of the taxon the name refers to, and therefore changes when the hypothesis changes. In hindsight, the binomen was a bad idea.
Jerzy asked about Cyanistes ombrosus. By coincidence I was reading about the splitting up of the genus Parus only a couple of hours ago.
Cyanistes ombrosus was until recently Parus caeruleus ombrosus - one of the Canary Island subspecies of the Blue Tit. The Canary Island forms of blue tit have long been suspected as being distinct and are now generally treated as a distinct species (consisiting of several subspecies). I remember the first time I watched them on Tenerife (actually a different but very close subspecies)thinking that they not only looked rather different, their behaviour was also distinct. There has been some debate about the relationship of North African blue tits - whether they belong with the canary island species, the Eurasian species or are another distinct species. I'm inclined to think the latter.
The old genus Parus has been split into several (including Periparus, Poecile & Baeolophus). The Great Tit and its close relatives are retained in Parus. The group made up of the blue tits, azure tit and yellow-breasted tit is now Cyanistes.
... which is why, in the absence of strong evidence, I favour naming new genera over new species. A genus is a single-word name, so the name does not in itself include a phylogenetic hypothesis. A monogeneric species-name is also a single-word name -- just one that happens to be spelled with a space in the middle.
(But, yes, this approach works better for sauropods than for beetles :-)
Well it certainly looks like a common lizard, if you ignore the colour of course. Ive seen common lizards with green flanks but not that green and never green all over - interesting find!
I'm a bit confused here. If Lacerta was horribly paraphyletic, why would the authours remove any species at all? Wouldn't the solution to the paraphyly problem be to lump all the species that were formerly in a separate genus, into Lacerta (e.g. the Melanosuchus fiasco of a few years back)?
This sounds more like a polyphyly problem.
"The old genus Parus has been split into several (including Periparus, Poecile & Baeolophus). The Great Tit and its close relatives are retained in Parus. The group made up of the blue tits, azure tit and yellow-breasted tit is now Cyanistes."
I've never understood the reason for this, as there seems to be little doubt that the group is indeed monophyletic, so there aren't the same issues as in Lacerta. OK, there's Pseudopodoces and maybe Melanochlora, but what's wrong with including these in the genus Parus and giving Poecile, Cyanistes etc. subgeneric rank? In the past, it has been mostly N. American ornithologists who have split the genus Parus, the Europeans have been a bit more conservative. I think this has to do with the fact that in N. America there are only representatives of two "genera" (Poecile and Baeolophus), while here in Europe we have Parus, Cyanistes, Lophophanes, Poecile and Periparus.
Of course, I know that it's completely subjective whether anything is a genus or not, but in this case I don't think there is a good reason for splitting. I can't say anything about whether it's justified in Lacerta, as I don't know any details in that case.
I've seen viviparous lizards on the North Yorks Moors that were a bronzy-green colour, but what must be the oddest colour form of this species recorded was photographed in "British Wildlife" magazine a couple of years ago. It was black, with orange blotches, and resembled the pattern of a Fire Salamander.
Lacerta already had 38 species (according to Wikipedia). I suppose that made it pretty unmanageable -- especially because the ICZN only allows two ranks between genus and species (subgenus and species group). Besides, I submit it should be emphasized that squamates are more diverse than mammals :-)
(Ceterum censeo Varanum esse delendum. For neontologists Varanus is already redundant with Varanidae, isn't it?)
What is unmanageable in genus with 38 species? There are lots of common genera like that.
Tetrapod genera with 38 species?
Also, that's the number for the old paraphyletic version of Lacerta. If you added, say, Podarcis back, you'd reach 58. If you add Acanthodactylus, the total climbs to 97... add Eremias, and you get 126... and adding Iberolacerta gives a total of 131. Is that a meaningful total? Which genera is the traditional version of Lacerta paraphyletic to?
Bufo was recently exploded, Rana was taken apart and probably doesn't reach 38 anymore, Leptodactylus is a mess that will be scattered about like confetti... I think that leaves Hyla as a really large genus. So, Hyla, Varanus, and anything else?
Well, Accipiter has bold 50, Anas 48 and growing and Anthus a sound 43, to begin with.
Actually Dutch twitchers reinstalled split of Anas few years ago and backed up again, because orntihologist considered it strange.
...ornithologist-s. Dutch don't back up from just one person1
For mammals...
Lepus: ~32
Ochotona: 30
Ctenomys: 60
Microtus: 62
Peromyscus: 55
Sciurus: 29
Spermophilus: 39
Gerbillus: 38
Mus: 38
Rattus: 54
Sorex: 76
Pteropus: 64
Rhinolophus: 67
Hipposideros: 54
Myotis: 78
Pipistrellus: 33
Crocidura: a whopping 176 species.
Among primates, Callicebus, Callithrix, Cercopithecus and Macaca have more than 20 species each.
For birds, just a brief skim-through since I've spent too much time on this comment already, Corvus has ~50 species, Charadrius has 31, Larus 49, Caprimulgus ~59, Falco ~39. And then there's the horribly messy genera like Buteo, Aquila and Phalacrocorax.
In birds, there are also *Amazona* and *Pyrrhura* that have a total of about 30 recognised full species each. In the case of the latter, splitting the genus up would be very hard because the species are indeed very similar.*Amazona* would be a bit easier as the genus is rather diverse. In fact, *Apliopsitta xanthops* has been removed from the genus in recent years. It was overdue;I'm familiar with the species and it is not like *Amazona* at all.
*Zosterops* is another very sizeable avian genus with hard-to-distinguish-members. Wikipedia says there are 75(!). I suspect this may the be the recordholder where avians are concerned.
Let's not forget Anolis, which is currently bloated at 400 species.
Talk about unmanageable.
Wow. Thanks very much, all.
I propose to nuke Anolis from orbit.
Whoah there Ripley :) Note that Anolis sensu lato has already been the focus of several attempts to split it up. For a review see...
Cannatella, D. C. & de Queiroz, K. 1989. Phylogenetic systematics of the anoles: is a new taxonomy warranted? Systematic Zoology 38, 57-69.