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Does anyone have some information as to whether the genus designation of North American rat snakes as Pantherophis instead of Elaphe is permanent, or just another temporary shift in taxonomy?

>>Does anyone have some information as to whether the genus designation of North American rat snakes as Pantherophis instead of Elaphe is permanent, or just another temporary shift in taxonomy?

Likely to be permanent. The fact that Elaphe, as traditionally conceived, was a grossly artificial assemblage has been an open secret for a long time, as has the fact that the N. American Elaphe are more closely related to things like Lampropeltis and Pituophis than to any Old World Elaphe. The name Elaphe "belongs" with a European species, so acknowledging the two facts outlined above means that the N. American ones need a different genus. This they now have: Pantherophis.

Cheers,

Wolfgang
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Its gonna be so hard to not use Elaphe!

Well.. don't you think that it will come easy wenn more and more people start using these "new" names, and we kind of get used to seing them. I have used Pantherophis now for several months, and quite frankly it looks odd to me when i see the name Elaphe guttata e.g.

The same holds try with my Zamenis longissimus and Zamenis situla, which were also previously part of Elaphe.
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Regards

Jan Grathwohl

I still occasionally lapse into using Natrix for N.A. water snakes!

Tom Lott

... if you find yourself lapsing into using Eutaenia for Thamnophis!

I do know the feeling, though.

Cheers,

Wolfgang

>>I still occasionally lapse into using Natrix for N.A. water snakes!
>>
>>Tom Lott
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Funny story (maybe) I had a proffesor in college that did his masters thesis on the a particular species (I don't think it was on the whole genus) of NA water snakes. A week before his presentation (or whatever its called) they announced the name change from Natrix to Nerodia. Talk about timing. And how many people still use the term Chondro

Steve Schindler

I typed Chondropython viridis into Yahoo's search engine, and there are 10 pages of results. Among these is a web page from the Museum of Zoology at the University of Michigan. It appears that Kluge couldn't even convince his fellow scientists at the Museum to adopt his own taxonomic proposal! LOL!
Chondropython

New World Elaphe originated in the Old World. So, it is a descendant of a species of Old World Elaphe. Subsequently Lampropeltis, Pituophis, Arizona, Stilosoma, Cemophora et al. evolved from this immigrant. Classifying New World Elaphe in a different genus would render Old World Elaphe paraphyletic. That is certainly a good excuse to send Old World Elaphe to the chopping block. But since New World Elaphe is itself paraphyletic, it means New World Elaphe itself may have to be splintered into two or more genera. That gives the taxonomists and those who keep track of taxonomic changes a hobby, but it really does not do the scientific community at large any good.

>>New World Elaphe originated in the Old World. So, it is a descendant of a species of Old World Elaphe. Subsequently Lampropeltis, Pituophis, Arizona, Stilosoma, Cemophora et al. evolved from this immigrant. Classifying New World Elaphe in a different genus would render Old World Elaphe paraphyletic. That is certainly a good excuse to send Old World Elaphe to the chopping block. But since New World Elaphe is itself paraphyletic, it means New World Elaphe itself may have to be splintered into two or more genera. That gives the taxonomists and those who keep track of taxonomic changes a hobby, but it really does not do the scientific community at large any good.

I don't have the paper in front of me, but I don't think there is much evidence that Pantherophis (=New World Elaphe) is paraphyletic, once you remove Bogertophis and Senticolis. so I don't foresee any immediate need for further splitting within the New World group.

As to Old World Elaphe - the probolem there extends far beyond the New world Elaphe. The Old World Elaphe are absolutely all over the place in the colubrine tree - some, like radiata, are closer to racers and Ptyas than to the bulk of what was called Elaphe.

Whether one likes it or not, the predominant view among taxonomists is that classification and nomenclature should reflect phylogeny. This requires some reclassification as new evidence comes to light. While I agree that some of the rehashing of some taxa has been excessive, and not always based on particularly solid evidence, individual excesses do not invalidate the general principle. In the case of Elaphe, a thorough revision was long overdue. Whetehr all the splits proposed will turn out to be necessary or widely accepted is an open question, but I have no doubt that many of the new arrangements will become widely accepted.

Cheers,

Wolfgang
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New World Elaphe is paraphyletic.

Consider the following relationships:

((Elaphe guttata,Lampropeltis) Elaphe obsoleta)

or the following relationship:

((Elaphe obsoleta,Pituophis) Elaphe guttata)

The tree to which your were referring, probably that of Rodriguez-Robles, had a large number of unresolved polytomies. The maximum likelihood tree also had the surprising placement of Senticolis within the Lampropeltini even though it lacks the interpulmonary bronchus that is the synapomorphy of the Lampropeltini. Rodriguez-Robles' analysis is far from the final word. To propose taxonomic changes based on their tree(s) is premature and destructive. Senticolis is one of those ratsnakes that appear to be closer to the racers than to Elaphe. It has been removed from Elaphe. Other similar taxa can be removed. The remaining species should remain in Elaphe. The alternative is a plethora of new genera that are not distinguishable from one another. Certainly there are many who will accept the new arrangement. In fact, these people will accept ANY new arrangement. It is a hollow victory if one counts how many people blindly follow new taxonomic arrangements. A "victory" for the taxonomist is in reality a defeat for science. Unnecessary new taxonomic arrangements impedes scientific progress because it makes retrieving published information more difficult.

`New World Elaphe originated in the Old World. So, it is a descendant of a species of Old World Elaphe. Subsequently Lampropeltis, Pituophis, Arizona, Stilosoma, Cemophora et al. evolved from this immigrant. Classifying New World Elaphe in a different genus would render Old World Elaphe paraphyletic.'

I suggest you read Utiger et al's paper revising Elaphe. The results of their study include:

Elaphe as traditionally defined is paraphyletic (this's been obvious for a while, and is implied by what you write above, but also clearly refutes the claim that the split of Pantherophis from Elaphe renders Elaphe paraphyletic).

Pantherophis is not basal among the New World lampropeltinines studied, which included Pituophis, Lampropeltis, Senticolis, and Arizona.

` That is certainly a good excuse to send Old World Elaphe to the chopping block. But since New World Elaphe is itself paraphyletic, it means New World Elaphe itself may have to be splintered into two or more genera.'

They did send the Old World Elaphe to the chopping block, and New World `Elaphe', already splintered in the past by the segregation of Bogertophis and Senticolis, was further split by the creation of Pseudelaphe, which contains the old `Elaphe flavirufa'.

`That gives the taxonomists and those who keep track of taxonomic changes a hobby, but it really does not do the scientific community at large any good.'

I disagree. The taxonomical situation created by Utiger et al results in more morphologically and ecologically comprehensible taxa that better represent what is known about the history of the group. This paper's pretty much a best-case scenario as far as generic revisions in snakes go, IMO.

Patrick Alexander

You wrote:
I suggest you read Utiger et al's paper revising Elaphe. The results of their study include:

Elaphe as traditionally defined is paraphyletic (this's been obvious for a while, and is implied by
what you write above, but also clearly refutes the claim that the split of Pantherophis from Elaphe
renders Elaphe paraphyletic).

My response:
You are quite correct that whether or not Pantherophis is recognized, Elaphe is paraphyletic. However, there are some systematists who claim that Elaphe is polyphyletic. One would hope that practicing systematists should be able to distinguish between polyphyletic and paraphyletic but that is sadly not the case. More than once I have heard them explicitly claim that Elaphe is polyphyletic.

You wrote:
Pantherophis is not basal among the New World lampropeltinines studied, which included Pituophis, Lampropeltis, Senticolis, and Arizona.

My response:
That depends on how one defines "lampropeltinines." Long ago it was demonstrated that New World Elaphe and genera such as Lampropeltis, Pituophis and Arizona share the synapomorphy of an interpulmonary bronchus. This character is not present in Old World Elaphe. This fact has prompted some systematists to propose classifying New World Elaphe in a different genus than Old World Elaphe but no formal proposal has been made to effect such a change. Senticolis does not have the interpulmonary bronchus. Hence it is not a member of the Lampropeltini. I am not surprised that a study concludes that Old World Elaphe is not basal to Lampropeltini and Senticolis since Senticolis is one of those taxa that is more like a racer than a ratsnake. That is why I support Dowling's decision to remove it from Elaphe and place it in a genus of its own some years ago. Senticolis, being closer to the racers, is probably basal to Old World Elaphe and New World Elaphe.

Your wrote:
They did send the Old World Elaphe to the chopping block, and New World `Elaphe', already
splintered in the past by the segregation of Bogertophis and Senticolis, was further split by the
creation of Pseudelaphe, which contains the old `Elaphe flavirufa'.

My response:
I support the recognition of Bogertophis and Senticolis. As I predicted, Old World Elaphe is being splintered because of some systematists' ideological intolerance of paraphyletic taxa. Since many systematists, especially those who are the most knowledgeable and experienced, do not share this ideology, they would most likely not follow the new arrangement.

You wrote:
The taxonomical situation created by Utiger et al results in more morphologically and
ecologically comprehensible taxa that better represent what is known about the history of the group.

My response:
That does not seem to follow because Utiger et al. employ mtDNA data, which reveals nothing new about the morphology or ecology of this group. Further, those who only tolerate strictly "monophyletic" (sensu Hennig) taxa do not and cannot take morphology into account in their delimitation of taxa. They are obligated by their own ideology to classify all descendants of a common ancestor into a single taxon regardless of morphological disparity. An alternative to this excessive lumping is to split taxa into a large number of taxa, each of which is often indistinguishable morphologically from other taxa. Those who are ideologically intolerant of paraphyletic taxa are therefore faced with the unpleasant alternatives of either excessive splitting or excessive lumping. Kluge often takes the excessive lumping approach as he has lumped Calabaria, Lichanura and Charina into a single genus and also Morelia and Chondropython into another genus, while ignoring morphological differences among them. Utiger et al. are taking the opposite approach: excessive splitting. Instead of invalidating taxa such as Lampropeltis, Pituophis, Arizona, Cemophora and Stilosoma and bringing all of these species back into Elaphe, he is splintering Old World Elaphe. Under the old arrangement, one can be certain that all of the species within Elaphe are close relatives and that New World Elaphe is a migrant from the Old World. Under the new proposal, such information about the evolutionary history of New World Elaphe is lost. The new arrangement obscures relationships, although it does provide gratification for those who are on a crusade to destroy paraphyletic taxa.

`You are quite correct that whether or not Pantherophis is recognized, Elaphe is paraphyletic. However, there are some systematists who claim that Elaphe is polyphyletic. One would hope that practicing systematists should be able to distinguish between polyphyletic and paraphyletic but that is sadly not the case. More than once I have heard them explicitly claim that Elaphe is polyphyletic.'

And, even worse, some people forget which word they ought to use in online discussions. Utiger et al. demonstrate that Elaphe is polyphyletic. Sorry about the mistake.

`That depends on how one defines "lampropeltinines." Long ago it was demonstrated that New World Elaphe and genera such as Lampropeltis, Pituophis and Arizona share the synapomorphy of an interpulmonary bronchus. This character is not present in Old World Elaphe. This fact has prompted some systematists to propose classifying New World Elaphe in a different genus than Old World Elaphe but no formal proposal has been made to effect such a change.'

I disagree. The change was made by Utiger et al.

`Senticolis does not have the interpulmonary bronchus. Hence it is not a member of the Lampropeltini.'

Though the point was not addressed by Utiger et al, it is addressed by Rodriguez-Robles (`Molecular Systematics of New World lampropeltinine snakes (Colubridae): implications for biogeography and evolution of food habits' Biological Journal of the Linnean Society, v. 68)--Senticolis is a lampropeltinine if Lampropeltini is defined based on phylogeny rather than morphology.

`I am not surprised that a study concludes that Old World Elaphe is not basal to Lampropeltini and Senticolis since Senticolis is one of those taxa that is more like a racer than a ratsnake.'

The inclusion of Senticolis is not responsible for the derived status of Pantherophis (was Elaphe) within the lampropeltinines. Arizona, Bogertophis, Lampropeltis, and Pseudelaphe (was Elaphe) were also all basal compared to Pantherophis in the Utiger et al.'s phylogeny.

`That is why I support Dowling's decision to remove it from Elaphe and place it in a genus of its own some years ago. Senticolis, being closer to the racers, is probably basal to Old World Elaphe and New World Elaphe.'

As it would happen, according to Utiger et al.'s phylogeny Senticolis is not basal to Elaphe sensu lato, though it is basal to the rest of the Lampropeltinines.

No offense, but you really should read Utiger et al's paper before you decide that you disagree with them.

Patrick Alexander

You wrote:
And, even worse, some people forget which word they ought to use in online discussions. Utiger et al. demonstrate that Elaphe is polyphyletic. Sorry about the mistake.

My response:
That is a big mistake indeed. You must be reading a different paper than I do. Utiger et al. show that Elaphe is not polyphyletic. The Lampropeltini is nested within Elaphe. By excluding the species of the Lampropeltini, Elaphe is paraphyletic. It could be polyphyletic if Elaphe obsoleta, E. vulpina and E. guttata are only convergently similar to Elaphe. That is not likely considering that the species bracketing these species are all classified in Elaphe by other systematists before Utiger et al. apply the machete to this genus.

Your wrote:
Arizona, Bogertophis, Lampropeltis, and Pseudelaphe (was Elaphe) were also all basal compared to Pantherophis in the Utiger et al.'s phylogeny.

My response:
In their phylogeny, Elaphe sauromates is basal to Arizona, Lampropeltis and Elaphe obsoleta. That means the ancestor of Arizona, Lampropeltis and E. obsoleta is itself closely related to Elaphe sauromates. Alternatively, this ancestral species is nothing like Elaphe but somehow E. obsoleta, E. vulpina, and E. guttata and E. flavirufa re-evolved their Elaphe-like morphology from this derived ancestor by undergoing evolutionary reversal. The reversal hypothesis, though possible, is less parsimonious and unproven. Hence I submit that the ancestor of Arizona, Lampropeltis and Elaphe obsoleta is itself a species of Elaphe. That means New World Elaphe is also descended from a species of Old World Elaphe, making Elaphe paraphyletic. Of course, paraphyly does not bother me one iota. It does bother the cladists though, enough that they would use the red herring of polyphyly to justify splintering it.

You wrote:
As it would happen, according to Utiger et al.'s phylogeny Senticolis is not basal to Elaphe sensu lato, though it is basal to the rest of the Lampropeltinines.

My response:
This part of the tree is poorly supported.

You wrote:
No offense, but you really should read Utiger et al's paper before you decide that you disagree with them.
Patrick Alexander

My response:
None taken. I suggest that you practice what you preach because there is no evidence that Elaphe is polyphyletic from that paper, your assertion to the contrary not withstanding.

`That is a big mistake indeed.'

The distinction between paraphyly and polyphyly simply wasn't relevant to the point I was making, so I didn't pay as much attention as perhaps I should have. *shrug*

`In their phylogeny, Elaphe sauromates is basal to Arizona, Lampropeltis and Elaphe obsoleta.'

I would be interested to know how you came to that conclusion. Figures 3, 4, and 5 all show Elaphe sensu stricto and Lampropeltini (in the sense of Rodriguez-Robles and De Jesus-Escobar) as sister taxa.

Any analysis of the rest of this argument awaits validification of this point.

You said:
` Senticolis, being closer to the racers, is probably basal to Old World Elaphe and New World Elaphe.'

I said:
`As it would happen, according to Utiger et al.'s phylogeny Senticolis is not basal to Elaphe sensu lato, though it is basal to the rest of the Lampropeltinines.'

You said:
`This part of the tree is poorly supported.'

Under Utiger et al.'s phylogeny, rejection of Senticolis from Elaphe sensu lato would require rejection of Lampropeltini from Elaphe sensu lato and unequivocal polyphyly for Elaphe sensu lato. Though I don't think your prospects are good on either front, I think you'll have to choose your battle on this one.

Patrick Alexander

I wouldn't call Elaphe "grossly artificial." It is true that some of the species originally classified in this genus are closer to the racers than to the ratsnakes but most if not all of these species have been removed from Elaphe. The racers are the sister group to Elaphe, so it is no surprise that some forms seem to be intermediate between these two groups. These intermediate species may have been erroneously classified as Elaphe in the past. After these problematic species have been removed, the remaining species of Elaphe should form a natural assemblage. If there is any evidence that the ratsnakes are only similar to each other because of convergent evolution, then please let me know what that evidence is. The unsubstantiated claim that Old World Elaphe is polyphyletic sounds to me more like propaganda than science.

It is true that genera such as Lampropeltis, Arizona and Pituophis evolved from a New World Elaphe, but this species of Elaphe is almost certainly a migrant from the Old World that made it to the New World in the Miocene. It matters not one iota that the type species of Elaphe is an Old World species, since New World Elaphe is part of the Old World Elaphe clade. DNA evidence corroborates it. Without the New World Elaphe species and genera such as Lampropeltis, Arizona and Pituophis, Old World Elaphe would not be monophyletic sensu Hennig. Renaming the North American species of Elaphe Pantherophis only renders Old World Elaphe paraphyletic. I have no idea why any cladist would support that change. In terms of morphology, New World Elaphe differs from Old World Elaphe in having the interpulmonary bronchus, but is this character reason enough for the name change? I submit it is not.

For the sake of taxonomic stability, I surmise that most knowledgeable herpetologists would probably ignore the proposal to transfer the North American species of Elaphe to Pantherophis. Personally I am going to ignore it since it really does not do anything except to create more taxonomic chaos.

I have heard talk of the Pantheropis name change but have yet to find anything published on it much less reviewed and made official. Not saying they wont change it but unless I am seeing false info the name Elaphe was the 1st described which according to taxonomic rules means it's the good one. Unless of course they determine it to be incorrect. Still one taxonomist changing a name does not make it official until it is reviewed and passed by others.

I would be very interested in seeing whatever has been written on this so far and by whom.

Phil

Hi Phil

Actually, it has been published in a peer-reviewed journal (in contrast to the tripe coming out regarding certain other lineages).

The ref is

Utiger, R et al 'Molecular systematics and phylogeny of old and new world ratsnakes, Elaphe auct., and related genera.' Russian Journal of herpetology. 9(2):105-124

Send me an email and I'll send you a PDF copy.

Cheers
BGF
Venom & Toxin Database

>>I have heard talk of the Pantheropis name change but have yet to find anything published on it much less reviewed and made official. Not saying they wont change it but unless I am seeing false info the name Elaphe was the 1st described which according to taxonomic rules means it's the good one. Unless of course they determine it to be incorrect. Still one taxonomist changing a name does not make it official until it is reviewed and passed by others.

Priority is not the main issue here. Elaphe was described first. However, every genus has a type species. If the genus is split, then the name of the genus goes with the type species and its closest relatives. For the remainder of what used to be the large genus, replacement or new names have to be found.

In the case of Elaphe, the type species is Elaphe sauromates, a European rat snake. Consequently, the name Elaphe "belongs" in the first instance to this species and its relatives. A number of studies have shown that N. American "Elaphe" are more closely related to Lampropeltis and Pituophis than to E. sauromates. Consequently, they cannot be placed in the genus Elaphe. The oldest available generic name applicable to the N. American rat snakes is Pantherophis, hence this name is the one to use.

A whole bunch of other rat snakes in the Old World are also changing genus. The Aesculapian snake, for instance, is now Zamenis longissimus, Elaphe radiata is Coelognathus radiatus, etc.

Finally, there is no such thing as an "official" classification, there is only consensus among scientists, which is based on a shared feeling that the evidence used to generate a proposal for change is in fact adequate to support it. The fact that Elaphe in the old sense was an artificicial group was no state secret, but there was no clear alterantive view. Utiger and colleagues have now replaced the previous uncertainty with a new framework for classifying these creatures. That's why the changes they proposed are being accepted, whereas other changes or new genera are not being accepted until additional research confirms their validity.

Cheers,

Wolfgang
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Wolfgang wrote:
"A number of studies have shown that N. American "Elaphe" are more closely related to Lampropeltis and Pituophis than to E. sauromates. Consequently, they cannot be placed in the genus Elaphe. The oldest available generic name applicable to the N. American rat snakes is Pantherophis, hence this name is the one to use."

My response:
A number of studies in fact show that North American Elaphe is ancestral to Lampropeltis, Pituophis and Arizona, among other genera. There are also studies that show Old World Elaphe is ancestral to North American Elaphe. For example, Lopez and Maxson's (1995) mtDNA tree shows three Old World Elaphe species, namely Elaphe carinata, E. quatuorlineata and E. scalaris, forming a clade with N. American Elaphe, Lampropeltis, Cemophora and Pituophis. Since all members of a clade are equally closely related to one another, it is therefore incorrect to say that N. American Elaphe is closer to Lampropeltis than to Old World Elaphe. It is also incorrect to suggest that North American Elaphe cannot be placed in Elaphe. Even Utiger et al. (2002), who sent Elaphe to the chopping block, found that Elaphe sauromates, E. carinata and E. quatuorlineata are still classifiable in Elaphe. Since N. American Elaphe forms a clade with the E. sauromates clade, the name Elaphe can be retained for N. American Elaphe.

Wolfgang wrote:
"A whole bunch of other rat snakes in the Old World are also changing genus. The Aesculapian snake, for instance, is now Zamenis longissimus, Elaphe radiata is Coelognathus radiatus, etc. "

My response:
That is indeed Utiger et al.'s proposal. It is just a proposal. Their consensus tree is little more than one big unresolved polytomy. Their analysis largely failed to resolved phylogenetic relationships among the genera they recognize. Better resolution of relationships will undoubtedly lead to future taxonomic changes. Therefore it is premature to adopt their nomenclature. Retaining the name Elaphe and rejecting all of the new and resurrected genera is the better alternative since it is both consistent with their tree and it is less taxonomically destructive.

Wolfgang wrote:
"Finally, there is no such thing as an 'official' classification, there is only consensus among scientists, which is based on a shared feeling that the evidence used to generate a proposal for change is in fact adequate to support it. The fact that Elaphe in the old sense was an artificicial group was no state secret, but there was no clear alterantive view. Utiger and colleagues have now replaced the previous uncertainty with a new framework for classifying these creatures. That's why the changes they proposed are being accepted, whereas other changes or new genera are not being accepted until additional research confirms their validity.

My response:
Elaphe is not an artificial group, although some scientists "assume" that it is. Both Lopez and Maxson and Utiger et al. have shown that N. American Elaphe forms a clade with Old World Elaphe, with the racers as the sister group to the ratsnakes. Nevertheless Utiger et al. wanted to make a large number of taxonomic changes despite the fact that these changes are unnecessary. Scientists should scrutinize their data and decide for themselves whether a study that fails to resolve phylogenetic relationships should be the basis for wholesale taxonomic changes. Their proposal is being "accepted" by people who will accept any changes that are proposed. I expect most experienced herpetologists, especially those who are not cladists, to reject the Utiger et al.'s proposal.