Tuesday, May 06, 2008

In for a penny, in for a pound

Aw, hell, here's the turtle. When I was growing up, with Herbert Zim's Golden Guide to Reptiles and Amphibians, this was Clemmys marmorata, but recent work shows that it is closer to Emys and the name Actinemys has been resurrected for it. And it really was just crawling across the driveway last week. I stuck him in a bucket, hauled him to school to show my ecology students, and then turned him loose in the creek towards which he was slogging when he was apprehended. And it is a him--check out that tail, and his plastron has a stronger arch than my feet ever have.

I'm pretty pumped to know that these things are around here. They're not doing great these days. For obvious reasons--show me a body of water west of the Sierras that isn't the center of a tourist trap, housing development, or agricultural or industrial outflow and I'll explain the optics of mirages for you.

I really just blog about this stuff to make Darren jealous.

Go, turtle, go.

Labels: , ,


Anonymous Anonymous said...

What the hell - you're not going to support your fellow lab alum Jim Parham and call it Emys marmorata?


Feldman, C.R., and J.F. Parham. 2002. A molecular phylogeny for emydine turtles: taxonomic revision and the evolution of shell kinesis. Molecular Phylogenetics and Evolution 22(3):388-398.

Parham, J.F., and C.R. Feldman. 2002. Generic revisions of emydine turtles. Turtles and Tortoise Newsletter 6:28-30.

6:37 PM  
Blogger Dr. Vector said...

All I know is what I read on Wikipedia, which is currently supporting Actinemys. I assume that's on the basis of even more recent work, but when I checked there was no reference for the move from Emys to Actinemys. Most un-Wikipedia of them.

Darren probably knows. What say, O Tetragod?

6:47 PM  
Blogger Sarah Werning said...

oh man, I was going to leave a call for references.

We're using Emys in Herpetology

10:55 PM  
Blogger TheBrummell said...

Wait a minute. I was long ago told that "turtle" only applied to the marine reptiles with the flippers (or whatever those appendages are called), while all land-dwelling critters in that group were properly either "tortise" or "tarrapin". This dude's clearly got feet, therefore not a turtle. What did I miss?

4:38 PM  
Blogger Dr. Vector said...

Wait a minute. I was long ago told that "turtle" only applied to the marine reptiles

How long ago--like 1770? That distinction fell by the wayside a while ago. Turtles is turtles. Some of them are also tortoises, terrapins, cooters, sliders, or stinkpots, but those are just varieties of turtledom.

8:53 AM  
Anonymous Anonymous said...

Actinemys vs. Emys marmorata is a splitter/lumper debate rather than one being a more recent taxonomic consensus than the other. All recent molecular analyses recover a well-supported clade of Emys orbicularis, Emydoidea blandingii, and "Clemmys" marmorata. Most of these analyses find blandingii closer to orbicularis than to marmorata. All of the analyses find the genus Clemmys to be non-monophyletic; the other species placed in Clemmys are not closely related to marmorata.

Given this phylogenetic position, there are two choices. One choice is to keep orbicularis in Emys and blandingii in Emydoidea. This requires a separate genus for marmorata, which some folks have done, calling it Actinemys marmorata. The other option is to include orbicularis, blandingii, and marmorata in one genus, for which Emys is the first available name. Feldman & Parham (and also myself) prefer this approach because it maximizes the information content of the genus name - using Emys for all three species tells you that they are more closely related to each other than to any other turtle. If you keep each species in a different genus, the genus is redundant with respect to the species name, it doesn't tell you any additional information, and certainly nothing about the relationships of the different species. Feldman and Parham (2002) explain their taxonomic decision on pg. 394:

"Our mtDNA phylogeny also shows that “C.marmorata is not closely related to Calemys or Clemmys, but shares a more recent common ancestor with Emys orbicularis and Emyd. blandingii. The generic name Actinemys Agassiz 1857 is available for “C.marmorata, but use of this name would obscure the phylogenetic affinities of “C.marmorata and its relatives. Excluding fossil taxa, the resurrection of Actinemys results in a well-supported clade composed of three closely related yet monotypic genera (Actinemys, Emys, and Emydoidea). Instead, the oldest generic name applied to this clade is Emys Dumeril 1806, and we recommend this name be applied to all three species. An expanded Emys more accurately demonstrates our knowledge of evolutionary descent. Before Loveridge and Williams (1957), most authors recognized the affinities of Emys orbicularis and Emyd. blandingii by placing both in the genus Emys. Similarly, “Clemmysmarmorata was originally described as Emys marmorata Baird and Girard, 1852. Although Emys marmorata lacks plastral kinesis, it does have reduced plastral buttresses. Furthermore, Emys species share several morphological similarities; all are medium-sized turtles that possess nonkeeled shells with patterns of radiating spots or lines on the carapace. Emys species are typically olive, brown, or black with some yellow. Unlike other emydines, they lack red scales. And with the exception of Calemys insculpta, the only emydines to range higher than 45° latitude are the species of Emys. Finally, Emys are the only emydines that retain fully webbed feet."


3:30 PM  

Post a Comment

<< Home