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NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 1:50 pm
by Gabriel Martínez
Dear all,

I prefer to not enter in the discussion about the “new” species of RH. I think that is better to not think in them seriously and just read the names and enjoy :lol:

I´d wish to discuss in the forum about the new Squamata classification. Maybe you discuss about this in last months/years, but I didn´t see it...

As many of you know, in the last 10 years many DNA analysis have shown that legs are not so important in reptiles, and the traditional classification in Sauria (including geckos, lizards, monitors, etc…), amphisbaenians and snakes is not correct and totally far of the real classification of Squamata.

Based on these analysis, there is a big group composed by the geckos (Gekkota), a big group with true lizards and amphisbaenians (Lacertidae), a big group of chamaleons, agamids and iguanians (Iguania), a big group including all skinks (Scincoidea or Scincomorpha fide Pyron et al., 2013 or Hedges 2014), a big group with glass lizars and monitors (Anguimorpha) and another big group with the snakes (Serpentes).

PYRON ET AL 2013.jpg
PYRON ET AL 2013.jpg (121.91 KiB) Viewed 6893 times


Although the analysis seems quite clear I can see that not everbody follow it. For example in reptiledatabase, they continue considering Amphisbaenia a own order different to Lacertidae. Leaving apart the question of the venom glands as important factor in the division of Squamata (the Toxicofera hyphotesis), what do you think about this classification? Do you think that we have enough scientifical support to consider that for example Podarcis and Blanus must be grouped in a same “clade”?

With Jeroen in the forum, it has been a strong tentation to try to open the discussion. Maybe is boring for many people, in that case, I´m sorry. For me it´s amazing to try to know the origin of our herps and relations between them!

Cheers

PD: I attach some comparative pictures to show how strange is the evolutive convergence!

SCINCOMORPHA.jpg
That south African lizard is closer to the skinks that to our Podarcis!


LACERTOIDEA.jpg
The Blanus is closer to Podarcis or Timon that to skinks or Typhlops


IGUANIA.jpg
Uromastyx and chamaleons are also closer that Uros and Timon for example

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 3:17 pm
by Peter Oefinger
Nice graph.
I think in some cases this tree is also supported by fossils (e.g. a Lacertid-like anchestor of Blanus from Grube Messel(?)).
What surprised me: if I understand that graph correctly, Agamidae, Chamaeleons & Anguidae are closer related to snakes than to Lacertids - is that right?

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 4:45 pm
by Gabriel Martínez
I got the graph of "Pyron RA, Burbrink FT, Wiens JJ. 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evol. Biol., 13, 93". It is amazing and very simple. I saw that article some years ago but was my friend Alberto Sanchez Vialas, the one who insisted me in the importance of that analysis to understand Squamata

Yes Peter, based in some of these works, true lizards and amphisbaenians are out of "Toxicofera" group that include snakes with agamids, chamaleons, glass lizards or monitors. If it was "strange" to image for example "Geckonia" chazaliae in the Tarentola genus or "Sphenops" sp. in Chalcides genus, these new analysis continue surprising. Platysaurus in south Africa looked like typical wall lizards both morphologically and in behaviour, and they are genetically very very different :roll:

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 11:28 pm
by Jeroen Speybroeck
I have to admit I have been avoiding this. I really need to dig into this. For our book, it's probable we are going to stick to the old ways. :oops:

But what I mainly wanted to say at this moment, is that I'm not too sure if you can/should interprete what this type of paper show at the lower taxonomic level. As an example, I have still no clue if the fact that they put Dinarolacerta inside Algyroides makes sense. I can give other examples from their work. A 2011 amphibian paper by the same authors showed Rana (now Pelophylax) bergeri as sister to Rana shqiperica and both not particular closely related to lessonae, whereas we now know the former is a subspecies of lessonae. Yet another paper showed Zamenis situla to be closer related to Rhinechis scalaris than to the other Zamenis.

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 11:42 pm
by Berislav Horvatic
Jeroen Speybroeck wrote:Yet another paper showed Zamenis situla to be closer related to Rhinechis scalaris than to the other Zamenis.

So, is it, or is it not? This is a DRASTIC example which noone should ignore. Forgive me my simplicity,
but when I look at the FACES of Zamenis situla and Zamenis longissimus, I find the same "expression"
- that duck-like face... you know. Could it be just a coincidence and nothing more than that?

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Mon Feb 08, 2016 11:59 pm
by Frédéric Seyffarth
For ratsnakes specially, it seems there is still a lot to work on...I am not convinced for example that "Elaphe carinata" is an Elaphe. I prefer "Phyllophis"...With the new DNA works, it seems that our "old way" to see snakes isn't right anymore. At first reading, i often find these works surprising, but after all, what is "really" right? Some various points of view...It is sometimes hard to understand, but still interesting. Although i have difficulties to understand all of these stuffs, i like this because i feel that we know more and more about our herps.
We used to make classifications about what we see (scales, teeths, colors, patterns, shapes etc...perhaps because it's our main sens?) but we ignored what we couldn't. Now it's like if somebody open THE book and show us what's Inside ;-)

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Tue Feb 09, 2016 12:42 am
by Jeroen Speybroeck
Here's the link to the 2011 snake paper.
http://vipersgarden.at/PDF_files/PDF-2256.pdf

I personally think that the Dinarolacerta case is more 'drastic', but I do agree that the head shape of situla and longissimus seems similar. If you look at the tree in that paper and also take the position of the other Zamenis species into account, the only sensible thing could be cancelling Rhinechis. But I repeat that I am assuming (for now) that these papers use markers and/or techniques that do not allow to zoom in too much on the lower taxa, but I need time to sort it out. For all I know, the answer may even be written plainly in the paper(s). ;) :oops:

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Tue Feb 09, 2016 12:47 am
by Berislav Horvatic
Frédéric Seyffarth wrote:With the new DNA works, it seems that our "old way" to see snakes isn't right anymore.
& c.

I totally agree with all you wrote. I feel exactly the same. As a scientist (a theoretical physicist),
I have no other way (out) than to accept a serious analysis - if it's serious and convincing enough.
These are the rules of the trade, our own rules, so grin and bear it, whether you like it or not...
Only, what's been left to (some of) us, the "simpletons"? Never mind, catching a Zamenis situla is
still an accomplishment I haven't had the luck with...

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Tue Feb 09, 2016 8:35 am
by Thomas Bader
For the Dinarolecerta Werner Mayer already told me in 2009, that his MT analysis showed that Dinarolacerta is very relative to the eastern Algyroides!

Re: NEW SQUAMATA CLASSIFICATION

PostPosted: Tue Feb 09, 2016 8:42 am
by Mario Schweiger
Jeroen Speybroeck wrote:As an example, I have still no clue if the fact that they put Dinarolacerta inside Algyroides makes sense.


not really new ;)
This has been proposed by Werner MAYER many yeas ago. Unfortunately he doesn't reach the age to publish it :shock:
But there are some lines about in a paper by Werner (author or co-author), which I can't find at the moment