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View Full Version : Just when you thought you had a handle on tegu systematics.....



tupinambis
09-09-2012, 06:40 AM
Well folks, it appears once again someone has felt it necessary (and rightly so) to revamp Teiidae systematics. If fully accepted, it means what we call tegus are now divided into two genuses, much along the lines of the previous 'clades' that I've sometimes talked about. This revision is purely based on morphology, and although they do a generally indepth analysis, it is clear the authors are not as familiar with the material as I'd like them to be (ie. for one, they continue to stress the importance of one vs. two loreal scales between the two groups, and as anyone with enough experience will point out, there are rather common exceptions to this).
So, according to this new scheme, they've re-enlisted the old genus of Salvator first proposed by Dumeril and Bibron in 1839. With this new scheme we now have:

Salvator duseni Yellow or Duseni's tegu
Salvator rufescens Argentine Red Tegu
Salvator merianae So many names......
Tupinambis teguixin Colombian Black&White/Gold tegu
Tupinambis longilineus Rhondonia tegu
Tupinambis palustris Swamp tegu (I was rather pleased my old friends' designation stood, there was contention by some that this wasn't a distinct species)
Tupinambis quadrilineatus Four-lined tegu

While I think this is a great development, I still have some reservations, and I'd REALLY like someone to do a more modern up-to-date genetic analysis.

tupinambis
09-09-2012, 07:13 AM
Oops, sorry folks, I forgot to write up the reference:

Harvey, M.B., Ugueto, G.N., & Gutberlet, R.L.Jr., 2012. Review of Teiid Morphology with a Revised Taxonomy and Phylogeny of the Teiidae (Lepidosauria: Squamata). Zootaxa 3459: 1-156.

http://www.mapress.com/zootaxa/2012/f/z03459p156f.pdf

And you read it here first on the internet's #1 site for tegu information, www.thetegu.com (http://www.thetegu.com)

laurarfl
09-09-2012, 04:09 PM
haha, yes, this is the #1 site for scientific information because we have YOU!

Do you mind if I share with others?

tupinambis
09-09-2012, 04:50 PM
Not at all, that is why I posted it here.

chriswizz
09-09-2012, 07:05 PM
so will the blue & b&w still have the same name.

tupinambis
09-09-2012, 07:40 PM
The blue is a morph of what you hobbyists like to call the Argentinian black & white tegu, therefore it is now called Salvator merianae.

laurarfl
09-10-2012, 12:39 AM
In your opinion, is that a valid classification, blue as Salvator merianae?

RamblinRose
09-10-2012, 02:35 AM
Fantastic news! Thanks for all the info. : )

txrepgirl
09-10-2012, 03:53 AM
Thank God that we have you tupinambis on our team :) . I'm very honored. It would be great to have some photos with those names for our new members. Thank you for all your help.

tupinambis
09-10-2012, 05:24 AM
In your opinion, is that a valid classification, blue as Salvator merianae?

Not exactly sure what you are asking here. In my opinion, yes, blues are Salvator merianae. As are Chacoans, Extreme giants, Argentine black & whites, and any number of other common names that crop up. Or, to put it another way, these are all the same species (albeit, the concept of species is more traditional than accurate, but that's another discussion).

Are you asking whether I accept the resurrected genus Salvator? Yes, but with caution. The problem I have with this new revision is that it is solely on morphology. Morphology is a good start, but anyone familiar with taxonomy can tell you that morphology (the more traditional system) has its limitations, and depends immensely on the characters the scientists choose to use and the weight they give those characters (admittedly, the same can be said for other comparisons, but it is more so with morphology). In other words, the criteria used can be quite arbitrary. This has lead us to classification systems in the past that proved to be quite faulty when compared with modern genetic analysis. For instance, in older morphological based systematics systems, Rodents and Bats were considered closely related. Modern genetic analysis showed this to be quite erroneous, and Bats have actually turned out to be much more closely related to Primates. Now all this being said, an earlier genetic analysis by Fitzgerald et al. (1991) did show a rather strongly divergent separation between the two clades. However, Fitzgerald's analysis was rather incomplete, and because of his comparison groups, wasn't really focusing on whether Tupinambis should be split up into 2 genuses, or, better put, that Tupinambis was polyphyletic.

Do I accept the term Salvator? If the divide between the two clades is great enough to warrant 2 genuses, then indeed this is a valid name. It isn't pulled out of nowhere, it was initially used to describe specimens that we would identify as Argentines. Likewise, Tupinambis was originally used to describe species we would recognize as Colombians.

RamblinRose
09-10-2012, 12:11 PM
At least it is a "start"... somewhere. Least now, perhaps it will all be further investigated, in a more "modern" way, even if it is not in my life time. :)

tupinambis
09-10-2012, 02:43 PM
As much as I support this revision, I have to admit after reading further into it, that the strength behind their claims for Salvator/Tupinambis is extremely weak. I don't mean that there's not a basis at all, but when you look at how many specimens they looked at for each species - maybe one or two for the tegus, NONE from Brasil (where by far the majority exist)...well, all I can say is it doesn't give them a real grasp of the diversity available in each species (or, hence, the need to look more closely at each species to determine if there aren't any cryptics in the lot).

laurarfl
09-10-2012, 11:22 PM
Then it surprises me that something that significant would hold up to peer review and general acceptance.

laurarfl
09-10-2012, 11:24 PM
Sorry, I read the latest posts first so I am out of order. I guess what I was originally asking was if you thought the blue tegu belong in the merianae species, whatever the genus :).

And I'm going to send you a PM about another issue.

RamblinRose
09-17-2012, 12:50 PM
Oh sure....tupinambis, Just give some hope, to burst my bubble! :roll: LOL