Reptile & Amphibian Forums

Curious as to the current status of E. beniensis. Has it been officially accepted as a valid species. Thanks,

Kelly

>>Curious as to the current status of E. beniensis. Has it been officially accepted as a valid species. Thanks,

There is no such thing as "official" acceptance - there is no "official" body that judges these things, and even though some checklists, such as the EMBL database and the "Snake Species of the World" book series, give the impression of being in some way "official", they are not.

Workers who have occasion to deal with a new species after its description have to decide whether they find the evidence presented to show that the new species really is a distinct biological entity convincing. If they do, they will accept the new species and include it in their work, if not, then they won't. Thus, a consensus is gradually built up, until the next revision of the group.

In the case of Eunectes beniensis, there is evidence from a number of characters, recorded as part of the first major revision of the anacondas for 50 or so years, that suggests that it is a distinct anaconda, so personally, I would have no problem accepting it.

Cheers,

Wolfgang
-----
WW Home

Wolfgang,
Thanks for the comments. The term “official” was a poor choice of words on my part. You are correct however, in that I assumed Snake Species of the World was the accepted standard due to it’s reference in CITES nomenclature issues. Thanks for the clarification. Is the major Eunectes revision you are referring to that of Dirksen’s 2002 publication, and if so, is it available in an English translation. Thanks again,

Kelly

Hi Kelly,

>>Wolfgang,
>>Thanks for the comments. The term “official” was a poor choice of words on my part. You are correct however, in that I assumed Snake Species of the World was the accepted standard due to it’s reference in CITES nomenclature issues.

That means that CITES has decided to adopt this book as the basis for ITS species lists. However, that does not confer on that book any kind of authority inde ciding whether a name is valid or not.

>>Thanks for the clarification. Is the major Eunectes revision you are referring to that of Dirksen’s 2002 publication, and if so, is it available in an English translation. Thanks again,

Yes, it is Dirksen's book. I am not aware of an English language edition. It was published by a germanpublisher whose specialty if the publication of German PhD dissertations. I don't think any of them have been translated, although I could certainly see a market for English versions of some of them.

Cheers,

Wolfgang
-----
WW Home

Wolfgang,
Thanks again for your help.

Kelly

WW wrote:
"In the case of Eunectes beniensis, there is evidence from a number of characters, recorded as part of the first major revision of the anacondas for 50 or so years, that suggests that it is a distinct anaconda, so personally, I would have no problem accepting it."

WW is apparently employing typology here, since he is recognizing "E. beniensis" as a distinct species on the basis it has a different morphotype.

Please elaborate on your disagreement with WW's interpretation. Thanks,

Kelly

Let me quote Herndon Dowling, who criticized Collins' proposal to use the so-called evolutionary species concept to elevate many subspecies to new species. WW's methodology is quite similar so Dowling's comments applies to him as well.

"In summary, Collins’s methodology is reminiscent of, and perhaps an attempt to return to, 'Taylor Taxonomy.' E. H. Taylor was a very active and long-lived herpetologist (in Collins’s same institution at Kansas) whom I admired in many respects. His working method, however, led to a plethora of species descriptions--many of which were later shown to be invalid. I was able to observe this methodology a number of times. Taylor would set out a number of museum specimens for study, and would methodically observe, measure, and record the various morphological features of each specimen. If he came upon one that appeared different or otherwise interesting, he would consult the original descriptions of appropriate, presumably similar taxa, and compare those descriptions with the specimen in hand. If the specimen differed (or was distinguishable) from the characteristics described by the previous authors, it was obviously a different taxon, and so he described it as new. Collins’s method is similar, but without the close examination of specimens."

Unlike Collins, WW do examine museum specimens. Like Collins, WW is trying to return to "Taylor taxonomy." For example, WW described "Drymarchon melanurus" as a new species (distinct from Drymarchon corais, because "D. melanurus" is morphologically different from D. corais. Like Edward Taylor, many of the species WW and his comrades (who subscribe to typological species concepts) recognize will almost certainly be shown to be invalid by later workers who re-examine the same material.

>>Unlike Collins, WW do examine museum specimens. Like Collins, WW is trying to return to "Taylor taxonomy." For example, WW described "Drymarchon melanurus" as a new species (distinct from Drymarchon corais, because "D. melanurus" is morphologically different from D. corais. Like Edward Taylor, many of the species WW and his comrades (who subscribe to typological species concepts) recognize will almost certainly be shown to be invalid by later workers who re-examine the same material.

For the record:

(i) Had you taken the trouble to actually read the paper you purport to criticise, and if you had even the faintest glimmer of knowledge of the genus Drymarchon, then you would know that I did not describe D. melanurus as a new species but raised it to species level from subspecies level (at which it had been recognised for many decades), and that I instead described a different species as new. The link to a web site dealing with the matter, and from where you can download the paper, is given below.

(ii) Documenting sympatry between morphologically distinct species is about the most common way of inferring that they are distinct species, irrespective of whether you adhere to BSC, ESC, PSC or whatever. For about 90% of all species recognised today, that is ALL the evidence we have, and I suspect that for a lot of them, the evidence is a heck of a lot less strong than for Drymarchon. Are you saying that we should de-recognise 90% of the world's biodiversity because the original description did not adhere to your high standards of evidence? Standards of evidence documented by your numerous publications which anyone can find with a simple search....... oh, hang on, what did you say your name was?

Get a life.

Cheers,

WW
Indigo Snake Systematics Page

-----
WW Home

Dowling writes:
"If Taylor came upon one [specimen] that appeared different or otherwise interesting, he would consult the original descriptions of appropriate, presumably similar taxa, and compare those descriptions with the specimen in hand. If the specimen differed (or was distinguishable) from the characteristics described by the previous authors, it was obviously a different taxon, and so he described it as new."

WW writes:
"The study was initiated as a result of finding a freshly road-killed specimen of Drymarchon during fieldwork in the state of Falcón, NW Venezuela. The specimen could not be assigned to one of the previously known taxa of Drymarchon found in Venezuela, which are Drymarchon corais corais and D. c. melanurus. This prompted the authors to initiate a study of the systematics of the South American representatives of the genus.... The results (see below) show the existence of three highly distinct taxa of Drymarchon in mainland South America: the populations conventionally assigned to Drymarchon corais corais, those conventionally assigned to D.c. melanurus, and those representing the species of the mysterious road-killed specimen."

The similarities between what Dowling wrote and what WW wrote are hauntingly similar. In both cases, a new specimen that is unusual or otherwise interesting was found. That helps launch a study, which compares the unusual specimen to the old taxa morphologically. When morphological differences are found, then new taxa are named.

In fact, WW even openly admits that he agree with Collins' (1991) taxonomic proposal, which Dowling criticized as "Taylor taxonomy." Clearly Collins and WW are both practicing "Taylor taxonomy" since they are in agreement on the taxonomic status of "Drymarchon couperi." But like many of Taylor's taxa, WW's and Collins' taxa will undoubtedly be shown to be conspecific with existing taxa by subsequent workers.

>>WW wrote:
>>"In the case of Eunectes beniensis, there is evidence from a number of characters, recorded as part of the first major revision of the anacondas for 50 or so years, that suggests that it is a distinct anaconda, so personally, I would have no problem accepting it."
>>
>>WW is apparently employing typology here, since he is recognizing "E. beniensis" as a distinct species on the basis it has a different morphotype.
>>

Perhaps you would care to provide a reference (from Mayr or Kardong, your usual deities - or the only people whose papers you have read?) for the percentage of species described today for which any other data, particularly on reproductive isolation, is available?

You will probably find that if we use that criterion, the world's biodiversity comes down from an estimated 10-30 million species to approx. 2000, almost all vertebrates and/or medically and economically species. Biodiversity crisis? What biodiversity? What crisis?

Cheers,

Wolfgang
-----
WW Home

WW wrote:
"You will probably find that if we use that criterion, the world's biodiversity comes down from an estimated 10-30 million species to approx. 2000, almost all vertebrates and/or medically and economically species. Biodiversity crisis? What biodiversity? What crisis?"

That is not true at all. According to Ernst Mayr, an application of the biological species concept in the late 1800 to early 20th century resulted in just 300 species of birds in North America being reclassified as subspecies. The number of species of birds world wide currently recognized under the BSC exceeds 9,700.

`There is no such thing as "official" acceptance - there is no "official" body that judges these things.'

I thought that's what the ICZN was for...

Patrick Alexander

>>`There is no such thing as "official" acceptance - there is no "official" body that judges these things.'
>>
>>I thought that's what the ICZN was for...

The ICZN is not there to give the seal of approval (or not) to every taxonomic act. It does not adjudicate on scientific quality, it merely establishes procedures which govern whether *names* are available (which is, for instance, why Hoser's many names, or at least most of them, are available - he has followed the bureaucratic rules of the Code - whether the species he has attached the names to are valid biological entities is another question).

The ICZN is responsible for publishing the Code of Zoological Nomenclature, which lays down the rules whether or not a name is available. These are rules that govern factes such as medium of publication, requirement for types and diagnoses, and rules such as priority etc.

The ICZN also has the power to make rulings where a strict interpretations of the Code would go against the interest of stability and universality of the nomenclature. For instance, if you suddenly discover an older, largely forgotten name (which would take precedence under a strict interpretation of the rules) for a well-know taxon that has long been known under a more recent name, then the ICZN can set the provisions of the Code aside to preserve the stability of the nomenclature.

Think of the ICZN as a road trafic tribunal: you don't have to call the judge every time you want to make a left turn, but if someone screws up, the tribunal will sort it out.

Cheers,

Wolfgang
-----
WW Home

WW wrote:
"The ICZN also has the power to make rulings where a strict interpretations of the Code would go against the interest of stability and universality of the nomenclature. For instance, if you suddenly discover an older, largely forgotten name (which would take precedence under a strict interpretation of the rules) for a well-know taxon that has long been known under a more recent name, then the ICZN can set the provisions of the Code aside to preserve the stability of the nomenclature. "

The ICZN can also be called upon to preserve an established name that contains grammatical errors. The ICZN promotes taxonomic stability. The cladists are trying to destroy it. Some radical cladists are trying to do away with the Code altogether. You can find discussions by some to abandon the Code and replace it with the "Phylocode" in sci.bio.paleontology.

I am pleased to see folks discussing E. beniensis. I'd like to add my 2 cents to the discussion. I am a biogeographer who specializes in the Llanos de Moxos savannas of the Beni Department of Bolivia, home of E. beniensis. The Beni Department has records of E. beniensis, E. murinus, and E. notaeus.

There are reasonable ecological and biogeographic grounds for presuming the validity of E. beniensis. First, E. beniensis is restricted to seasonally inundated savannas while E. murinus is restricted to forested riverine environments (in the Beni at least). E. notaeus is a Pantanal and Humid Chaco species that enters the Beni via the upper Iténez/Guaporé connections to the Pantanal (upper Paraguay) basin. The Moxos savannas are isolated from the other major savannas of South America and contain a few known endemic vertebrates such as the blue-throated macaw (Ara glaucogularis); thus E. beniensis would not be an anomaly in region without other examples of local speciation.

Greetings from the southern edge of Amazonia,

Robert Langstroth
Llanos de Moxos