Quick Argentine / Colombian difference.

[Bubblz Calhoun]

This has been a common topic that keeps coming up. Since it can be hard to tell if you don't know what to look for and to add to it some retailers don't know or care to sell or label them correctly.

The common comparisons people use to use with loreal scales, linear lines (solid or not) and body patterns like most things vary. Some have one scale on one side and two on the other.
Just like some colombians have a dotted linear line along their side (some even solid) the same as some of the other tegus. Since their pattern changes and can break up as they get older no matter what type of tegu it is.

This pic quickly sums it up for me when determining the two. Hopefully it will help others as well for future reference when purchasing a tegu.

As a quick reference forget everything else and concentrate on the head.
The argentine is on the bottom left and the colombian is on the top right. The argentines head scales are pretty much white. While the colombians head scales are yellow with black spots and blotches.

At times the scale pattern on Colombians can resemble big cat animal patterns like cheetah, leopard and things like that. I have yet to see it (animal print) on any of the other tegu species. With some Colombians the scales on the side of their mouth may be a solid color but on top of their head it's blotched or spotted. Base colors vary from one species to the next but the concept is still the same when trying to determine colombian or golds from an argentine b&w.

Try it out and google tegu images. Just from the head alone you should be able to pick out any colombian or gold type pics from black and whites.

 

[chitodadon]

Great reference

from Samsung Galaxy S3

 

[bfb345]

There are large scales right behind the nostril I think they are called loreal scales but Columbians only have one and argentines have two

 

[Bubblz Calhoun]

bfb345 I covered loreal scales in my post but stick with that if you like... what ever works for you.

 

[Rhetoric]

Excellent bubblz. I stickied it, hopefully it helps people.

 

[bfb345]

bfb345 I covered loreal scales in my post but stick with that if you like... what ever works for you.

Sorry bubblz I didn't catch it the first time my bad

 

[Roadkill]

Except that as Bubblz has very correctly pointed out (albeit not too clearly), the loreal scales is not a consistent character trait. I have a lineage of Salvator merianae that all possess only single loreal scales, for example.

 

[Bubblz Calhoun]

Yeah.. I could have clarified that more. Can you post some pics of tegus with single loreal scales?

 

[Roadkill]

 

[Roadkill]

 

[laurarfl]

Thank you for the photos. Once you can identify T. teguixin (Colombian, gold, etc), you can always spot them. To me, it is the patterning and head shape in general.

Thanks for this sticky.

 

[Roadkill]

I would have to agree with you, Laura, the patterning is a good character (albeit one rather difficult to describe accurately) and general head shape is usually a pretty good give away. Members of Salvator genus typically have a more robust head with rounded snout, while members of the Tupinambis genus typically have a more angular head with an acute, more pointed snout. However, there are some exceptions. This old boy, for instance, has a rather angular head (albeit that may be due partly to scarification...) however the patterning is a dead give away (even with all the scarification):

 

[TheTeguGurl]

Great thread thank you

 

[battyrubble]

Very interesting, thank you!

 

[Awano]

Hey, partially off topic but I have not heard of using the genus Salvator and have always used Tupinambis myself. Is this a recent change in nomenclature?

 

[Roadkill]

Yes (and no), a paper came out last year reclassifying the whole Teiidae family, for tegus they proposed separating the genuses of the southern clade (what hobbyists typically refer to as Argentines) into Salvator, and the northern clade (what hobbyists typically refer to as Colombian and others not common to the trade) into Tupinambis. This may seem "new", but it is not. This comes from nomenclatural regulations wherein there is a "grandfather" clause that the first time a name is used to describe a species, then for any systematic changes to follow, the first name takes precedent. While they were all considered one genus, the genus epithet of the first name used to describe any one of the species (not sure exactly which one, but I don't think it was Tupinambis teguixin) was used for the whole genus. Now that they've reclassified it as two genuses, they supposedly went back into the literature and found the first time one of these guys was described was under the name Salvator. However, it could be more complicated than that, as I recall the first time they were described they were thought of as being Varanids, so I'm not exactly sure who was what when, as I'm fairly certain the name Tupinambis merianae was actually used before the name Tupinambis teguixin was used, but there's also the argument of exactly what was described as such (for example, and this is totally made up on my behalf, perhaps the name Varanus merianae was first used to describe a specimen from Brasil, later another specimen got described as Tupinambis and another as Salvator [in the early years, new names were being tossed around by every naturalist that had little means to check out what had been described by others] and when someone went back into the literature and keenly looked at what was described and where it was located, Varanus was clearly dropped because these were not related, and so the first new genus name adopted - Tupinambis - while despite merianae actually preceding teguixin, location and description clearly point to one lizard, while location and description clearly point to the other - it can get complicated, but suffice it to say these names aren't exactly new, just being recycled).

 

[Awano]

Thank you for the response Roadkill. It does seem like it can be pretty complicated. I did not know about the grandfather clause. Do you happen to have a link to the recent paper?

 

[Roadkill]

Now that I'm at home and have access to my personal literature:
The recent reclassification of the Teiidae family can be found at http://www.mapress.com/zootaxa/2012/f/z03459p156f.pdf
I found the analysis of the Genus Tupinambis quite shallow and displayed very little familiarity, but I and many others still agree the division is good.

As for the history of the names:
It appear Linnaeus himself described the first one, under the name Lacerta teguixin in 1758 on a specimen from Suriname (for some reason I keep forgetting he associated them with European lizards....I probably always overlook this as Linnaeus despised reptiles and amphibians).
There were a few other names afterwards, but the next one that is recognized was from Daudin in 1802 where he described Tupinambis monitor (although, to be fair, Lacepede wrote about "Le Tupinambis" in 1788 as a double genus, Lacertus Tupinambis).
Then in 1839, Dumeril & Bibron distinctly identified Salvator merianae and Salvator nigropunctatus. Since that time many other names have been bandied about, often mispellings (or worse), and nigropunctatus has been designated as a synonym of teguixin (However, there are rumblings that teguixin/nigropunctatus is about to change again).
So a simplistic synopsis would be Linnaeus first described a Colombian tegu as Lacerta teguixin (getting the genus wrong) which was later recognized to not be of the same genus as previously described Lacerta sp., and so the genus epithet of Tupinambis was created (although the species epithet used was monitor - and here we see "grandfathering" as although Linneaus screwed up on the genus, beings as he was the first to describe the new species in any fashion, the species epithet of teguixin stands, with the realization of the genus status, the first new genus epithet of Tupinambis stands). Later we get Dumeril & Bibron describing both an "Argentine" and a "Colombian" as Salvator merianae and Salvator nigropunctatus, respectively. Salvator would just be considered a synonym of Tupinambis, but the recent paper makes the case to split the genus, and so Salvator is revived (as the first name known to describe a member of that group) for that clade. As it currently stands, nigropunctatus is considered a synonym of teguixin, but if someone were to show there is a distinct "new" species, and that "new" species fit the description and general location of the specimen that Dumeril & Bibron used to describe Salvator nigropunctatus, then nigropunctatus would as well be revived to redescribe the "new" species. If it was a new species that didn't fit the description of Dumeril & Bibron, then the auther would have grounds for creating an entirely new name.

 

[Awano]

I never knew that choosing of names was such a political affair. It's also pretty interesting to see what people thought were the relationships between animals way back when. Seems like the common idea was that tegu were some type of monitor, even the new 'new' genus Salvator instantly reminded me of Varanus salvator.

 

[Roadkill]

Well, not so much political as it once was, regulations were established to cut a lot of politics out, and hence through these regulations there's a method to follow when giving names or reclassifying taxonomies. For example, while it may have been acceptable at one time, it is no longer acceptable to name a species/clade after yourself. You can name a new species after someone else (an honourable tribute) and this is still frequently done these days (I knew a small fly entomologist who got tired of trying to create descriptive names for each and every little species variant and so his strategy was to start naming flies after everyone in his lab or who he worked with), but you cannot describe a new species and name it after yourself. There's also a lot of emphasis to be very thorough and recheck stringently past species descriptions (even if thought erroneous) to be certain that what you want to describe possibly hasn't been covered in some manner by someone else (in the scientific literature you'll see discussions on how so'n'so wrote X as a completely novel species whereas if they had looked at Mr.Y's description of a previously named organism, you'll see the specimen had characteristic A, B, C, and F, which so'n'so overlooked, therefore their "novel" organism is really just a rehash, and the previous name should be adopted while the "novel" name is considered a synonym). Of course, then there's the simple case of something like what we see in the tegu species Tupinambis quadrilineatus. As I understand the situation, the authors credited with that species didn't exactly discover this species themselves, the tegus were just "rounded up" during a bio-relocation effort (in Brasil, they have this interesting idea that during a hydroelectric dam project or other major development, they try to capture all the animals in the area to be affected and relocate them somewhere safer), the people who caught them weren't sure what they were and so turned them over to a couple of well known tegu researchers, my friend Augusto Abe and Dr. Colli. I gather they immediately recognized they had a new species on their hands but didn't immediately make a move on describing them (they weren't exactly taxonomists). So they sat on this information for about 12 years before they (no longer working together) decided they really should write up the species and get it classified. So each independently wrote it up and submitted their papers to different journals. Augusto's paper (this time working with Paulo Manzini) got published something like a few months (1997) before Dr. Colli's got his published in another journal(1998), therefore by taxonomic regulations, the name Augusto & Paulo came up with (quadrilineatus) gets the classification and Dr.Colli's (which I do not recall at the moment) gets relegated to a synonym. The really interesting thing is they may have actually had several new species on their hands - I worked with several Tupinambis quadrilineatus in Augusto's collection when I was in Brasil (my avatar is one of them) and let me tell you, they don't really resemble the description that was submitted of them (we've always considered them atypical, but considering the vague nature of how they were discovered.....)