Reptile & Amphibian Forums

Hello everyone,

Considering the amount of controversy surrounding the current classification of saurians of the genus Crotaphytus, it is not difficult to see why so many people would rather avoid the topic. Even though systematics can be a bit tedious at times, it is important to know whether the name in question is valid or invalid under the respective authorities. Indeed, after a bit of research, I was very surprised to see how little has been accomplished regarding the correct taxonomic classification of collared lizards in general. For example, according to the Integrated Taxonomic Information System (ITIS), an important authority in partnership with agencies in Canda and Mexico, there are only six officially recognized species of collared lizards.

http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=173911

The ITIS also indicates that for example Crotaphytus collaris auriceps, is only a synonym and not a separate subspecies (Other people would argue otherwise).

http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=173912

Interestingly enough, the ITIS does not even mention Crotaphytus dickersonae in their official list; not even as a synonym. My first search yielded a list of valid and invalid names; none in particular order.

http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt

Another source, the Global Biodiversity Information Facility (GBIF), is perhaps a bit easier to understand, and has a more complete list of current names. The GBIF, like the previous source, only includes six species of collared lizards.

http://www.gbif.net/portal/ecat_browser.jsp?termsAccepted=true

Unlike the ITIS, this institution recognizes other "subspecies" of C. collaris exclusively as "unambiguous synonyms," not as actual subspecies.

http://www.gbif.net/portal/ecat_browser.jsp?taxonKey=235107&countryKey=0&resourceKey=0&showIncertae=false&nextTask=ecat_browser.jsp

The GBIF only goes so far as to recognize C. dickersonae with a "Tentative position in taxonomy..." In other words, it is invalid.

Other sources (most of which are not official) such as the EMBL Reptile Database, recognize not six, but seven separate species of the genus Crotaphytus.

http://srs.embl-heidelberg.de:8000/srs5bin/cgi-bin/wgetz?[REPTILIA-Species:Crotaphytus*]

This source, for example, outlines six synonyms and SIX SUBSPECIES for the species C. collaris; one of those includes Crotaphytus collaris dickersonae. According to this, Dickerson's collared lizard is not a separate species, but rather, a subspecies of C. collaris.

http://srs.embl-heidelberg.de:8000/srs5bin/cgi-bin/wgetz?-e [REPTILIA-Species:'Crotaphytus_SP_collaris']

Being so variable in appearance, even among species, you can see why some would automatically designate a name such as "yellow-head" and consider it a separate subspecies. But without further detailed studies, such as DNA testing, the controversy will continue.

In any case, we will continue to learn more about these magnificent animals, and hopefully one day we will be able to solve the mystery. And if you know of any other sources of information regarding their official taxonomic record, please... PLEASE let me know!

Regards,

Fabián Aguirre
Zookeeper/ Aquarist
Department of Herpetology and Freshwater Biology
The Dallas World Aquarium
fabian@dwazoo.com
www.dwazoo.com

*Congratulations on the neonate Eve!

Most people on this forum use the correct taxonomy. Some off the the sir=tes mentioned are not up to date. I think that all subspecies of collaris have been dropped or upgraded to species. For example auriceps is no longer a valid subspecies as it was dropped and is now officially just C. collaris. Go to Will Wells "Crazy Crotaphytus" page and I believe his taxonomy is the most updated.

The same is true of Sauromalus now(As of March 2004.). Sauromalus obesus is now S. ater. All supspecies of what used to be Sauromalus obesus such as tumidus and obesus have been dropped. Basically now I think all mainland chuckwallas are just S. ater with no subspecies.

Tom

Got a question--I unmderstand DNA questioning, but it's really interesting, like carbon 14 testing how reliable is the actual testing? Aren't there certian assunptions made in order to come to a conclusion, and isn't it at the discreation of the tester for results in some cases? My point is any one of us having handled chucks collards etc. can see a distinctive difference in the animals. What everyone calles a red back in certian locations is a different looking redback than others say in California. The scales count is different, the actual skin scales are different, and though they all come from a common ancestor they do have some distinctive differences, whether you call that a species or subspecies. I just find the discussion interesting, because inspite of the science many herpers and reptile handlers seem to know different. When it comes to color integrades and such like whiptail and racerrunners I'm with you, but even in this classification there are distictive differences that would lead one to consider one different from the other, inspite of having a common ancestor........

The work of J. A. McGuire is often cites as the latest authority on the species questions, as he has gone into some of these questions in great detail.

See:
.........
Bulletin of Carnegie Museum of Natural History
Number 32 (1996) ISSN 0145-9058

Phylogenetic Systematics of Crotaphytid Lizards
.........

-DonC.
-----
I've got the blues...LOL...them screamin' yellow-head blues...

Well, I find it all very interesting , as I think they are magnificent,

But I'm just glad God made YELLOW ONES ESPECIALLY FOR ME ! LOL

All kidding aside guys, Good conversation!
www.suncharmers.com

-----
Eve

HA HA, One day I will have a "yeller" one !
Hope everyones 4th was good!
This is my little angel kissing a frog!!

I think the collaris want to be heard. They don't want no stinking auriceps being called collaris anymore. I can't even keep my Utah yellowheads in the same pen...I have female C. collaris that think they need whipped.

J

Princes Chasing her one day soon, and will DRIVE HER DADDY CRAZY,

LMAO ! Shes BEAUTIFUL Donnie, you and your wife must be tickled PINK, heheheheh
-----
___

Eve

.

How long have you had this web-site? You have an amazing batch of animals, indeed very healthy and well taken care of. I hope to get a web-site shortly as I am hopefully getting my breeding projects off the ground for next year. I will post some of my critters in the not to distant future.

If so, Thank you Much ! I have tried to email you back, many times only to have them returned. TomG gave me your new addy, I just have been swamped in lizard care, heheheh !

Anyway I had made a little site for my photos and if I had hatchlings.

But it had pop ups and ads that were annoying, and the BIG thing, I had so many large pics on one page , it CRASHED my site. And I was never able to access it again. LOL

So , I rebuilt in my late night spare time, spread pics over more pages, and got my own site with NO FREAKIN POP UPS !

IT WAS FUN !
-----
___

Eve

Gosh, I aplogize for not changing the subject matter, I used the one above for your post. What a nitwitt. Anyway yes I was enamoured with your animals and they way you laid out your site.
Excellent.....

I appreciate your response and I will look this up, but the jist of my question was the reliablility of the testing? And thats probably what you're intimating to me with respect to getting answers. After having delt with every lizard specie you can think of at some time over the years, I have observed as well as others who know there species and subspecies that there are distinct differences in the animals. And I'm not talking about color intergradation but scale counts, skin texture, and other subtle differences that make one consider that these are not the same animals or fall under the same specie. This really is just an observation based upon experience and certianly is not scientific. I just get a little shakey when people make definitive statements about species and sub species, I find it interesting that the old guys who worte the books and spent the hours collecting and catolgueing observed the same types of differences as most herpers who have good experience observe as well. I used chuckwallas and Whiptails but there are other examples as well. Obviously there has been much discussion about this already, I was more interested in the viability of the tests that are used and the interpretation I have found by many supposed scientific methods were actually up to the bias of the tester. Just some observations from an old herper.

My female collaris will whip up on the yellow head females for some reason. I've even added new female collaris they've never met, and not seen that type of hatred LOL

J

...a bit more investigation. Some controlled test breedings X "regular" C. collaris, some of the stuff I hear makes me wonder if there is a lethal in the woodpile somewhere, in the supposed "same" species.

DC
-----
I've got the blues...LOL...them screamin' yellow-head blues...

a seperate species C. Aureceps I dont know why they changed that.

As far as what Will said earlier about c. collaris genes and C. bicinctores, mixing it up a bit, I have seen one in the classifieds that looks remarkably like a bicinctores, with yellow and blue.

Alot is going on, apparently.

But I say C. Aureceps as a species!
-----
___

Eve

I go with Jimmy McGuire's species account. I tmakes the most sense. Plus it can depend on what species concept you go with. The old theory for species was as long as they could mate and produce fertile offspring they were the same species.
Example: a horse and a donkey produces an infetile mule, different species. Since all collareds can breed and have fertile offspring, they could be classified as all the same species with different races(subspecies). Another species concept is if the species is on it's own evalutionary path, it is classified as a seperate species. Example: C. insularis is on an island and probably won't mix with the near but C. vestigiums. C. grismeri is on an isolated mountain chain and won't mix with the other species. There is usually some geographic border that keeps the different species from mixing whether it's a river, rock less terrain, or ocean. It gets tricky when a hybred zone is found. I read that there are collaris genes in the C. bicinctores in Arizona all the way west to the Colorado River. Interesting stuff!!!

I completely agree. The universal definition of "species" must be changed in order to accomodate viable hybrids. Studies at the molecular level, or phylogenetic studies involving skeletal and external factors need to be greatly expanded. I mean, take for example non-human primates such as chimpanzees. Chimps and humans are more than 98% similar at the gentic level, and that minor difference accounts for such a great gap between the two. So what percentage will it take in order to differentiate among species such as collareds, even though they are so similar in their morphology? Sure, perhaps external differences such as color, scale count, or even squamation are very obvious among the many "localities," but don't you think it could be that they are only in the process of becoming a separate species, but haven't gotten there yet? Surely, those animals living on islands, for example, are evolving much differently than those living on the mainland. But perhaps time has not allowed them to become a completely distinct subspecies.... yet. I am not of the opinion that squamation or coloration are a definite answer to the question, but I do agree that changes are occurring.

Cheers,

Fabian Aguirre
The Dallas World Aquarium

Fabian, I'm sure this type of thinking doens't set well with the scientific world, but, sin't possible that it is a distict species and is not "becoming" anything, but has always been? I see all these assumptions inspite of morphlogy which you so well pointed out chimps and humans are not the same. If you look at many recent discoveries of living fossils, bats, corocs, celocanth fishes, other devil fish, and toads, you'll notice that in millions of years these animals have not changes one iota? So without getting ionto much controversy and since we are all throwing out our opinions, it's interesting that some of the herpers here can see the distinction in collard lizard species, does natural selection take place of course, we know hybridization happens, such as horned lizards in the desert in San Diego county as another example. Anyway, I think this subject is is still raw and open for alot more investigation and discussion, and in spite of those that would use the evolutionary discussion to reach their conclusions -- there are other conclusions that can be reached that are just ified and just as "scientific" but ubaccepted by the scientifc community, which is constantly in flux with respect to some of these issues. I appreciate everyones input on this, and it certianly is an interesting subject............

On the strain of conversation about interspecies breeding.

Wolves and dogs have long been considered different species and can still produce fit offspring.

A very good example is also Bos indicus and Bos taurus cattle. They have been considered different species for centuries, possibly diverging over a thousand years ago. They were produced and maintained on different conitinets and still retain the ability to interbreed. In fact, most of the cattle produced in this country for meat are Brahman crosses.

Just an interesting example that I thought should be thrown in.

Laura