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Post by eriorguez on Feb 20, 2011 20:43:08 GMT
Not to mention, that Eotriceratops has characters in between Triceratops and other chasmosaurines, if I recall correctly. If it was to be lumped into Triceratops, Torosaurus and Nedoceratops would go first, as, even when not counted as ontogenic stages of Triceratops, are closer relatives of it that Eotriceratops. And it doesn't look like a giant Triceratops because it is roughly the same size; just like Torosaurus and Titanoceratops. And the skulls, particullary the frills, of most of these guys were badly crushed, and restored in museums. Titanoceratops was reconstructed to look like a Pentaceratops, as it was though to be one. upload.wikimedia.org/wikipedia/commons/9/97/Phylogenetic_relationships_of_Utahceratops_gettyi_and_Kosmoceratops_richardsoni_within_Ceratopsidae.jpgFrom the descriptions of Utahceratops and Kosmoceratops; Eotrike is basal to Toro+Trike, even if separate. Then we have "Torosaurus" utahensis, that quite likely is not even Torosaurus, and Nedoceratops, which was a quite sick individual and hard to get diagnosic things from. |
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Post by simon on Feb 20, 2011 21:41:50 GMT
" Triceratops" isn't a species, it's a genus that is currently thought to contain two species ( T. horridus and T. prorsus). If Eotriceratops were ever to be lumped into Triceratops, it would presumably become T. xerinsularis. Thank you. My ignorance of the operative terms shows itself yet again  I guess the point I was groping for was that Eotriceratops skull is presumably from a very old and large adult, and with the typical solid frill - hence - evidence to cast more doubt on the Torosaurs=Triceratops theory .... |
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Post by eriorguez on Feb 20, 2011 22:29:43 GMT
But Eotriceratops is just as closely related to Torosaurus as to Triceratops. And the skull was broken. And we don't know its ontogenic stage.
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Post by Griffin on Feb 20, 2011 22:30:55 GMT
There would need to be a Toro skull found amongst some Triceratops To be testable this hypothesis requires the assumption that this animal lived in groups, when actually it's likely Trike was a mainly solitary species. There's also evidence form other dinosaurs that the ones that did live in groups, only did it when they were "teenagers", so actually we wouldn't necessarily expect adult skulls to be mixed with subadults. To be scientifically valid, any idea needs to have a way to prove it wrong. The Toroceratops can be proved wrong if a juvenile Torosaurus skull is found that clearly differs from Triceratops. Or if a fully mature Triceratops skull (that is, cranial sutures fully fused) is found that clearly differs from Torosaurus. The alternate, the idea that Triceratops is NOT Toro, can be proved wrong if... well I can't think of anything. If nobody can, it's not scientific. That means the burden of proof is on the traditionalists right now. All this nonsense about size that people throw around online has no bearing on the question. Individual or population variation is too big a factor to make a difference. The question needs to be answered by anatomy. I personally don't think it's been answered. Neither side has not yet made a compelling case. But I also know that Horner's side has enough data to keep publishing papers for the next five years, and talking with Denver fowler etc., it seems like they really haven't even begun to present their case yet. The current paper is only an outline. Which, in hindsight, was probably a bad idea. They should have waited for study to be complete, and published a huge monograph all at once, to avoid these kind of debates where people (on both sides) don't have all the facts to begin with. I still don't think there is enough evidence to really make this a compelling argument. The ratio of triceratops to torosaurus remains on the fossil record is to steep for me to think that they were really the same species. We'll see. Maybe when more of these papers you mentioned come out I'll be swayed. But for now they are just too different for me to buy it. |
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Post by simon on Feb 21, 2011 19:06:23 GMT
To piggyback on something SBell alluded to - If the hypothesis proves correct, it will simply mean the elimination of Torosaurus and the expansion of Triceratops.
Once you think of it that way its not really threatening to the sensibilities ...
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Post by eriorguez on Feb 21, 2011 19:36:52 GMT
Nah, it is just making old Triceratops have a longer frill.
Plus, I don't think that, if it was the opposite, people would stop using Triceratops; in fact, who uses Agathaumas, which is the older, poorly diagnosed name? Yeah, Torosaurus has diagnosic features, but, in case it was older, I can see petitions being made.
Just like with flies and Drosophila; the ammount of papers that use Drosophila melanogaster is far wider that the ones that use any other species of the genus. D.melanogaster is very distant from the type and closer to other genera, so it may be prone to splitting. Geneticists are pretty much giving an applause to taxonomists so they don't feel bad, then continuing to use D.melanogaster.
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Post by Griffin on Feb 21, 2011 21:58:05 GMT
To piggyback on something SBell alluded to - If the hypothesis proves correct, it will simply mean the elimination of Torosaurus and the expansion of Triceratops. Once you think of it that way its not really threatening to the sensibilities ... Its not that I'm threatened by it at all. Whatever it is it is. I just don't think the theory is strong enough yet. Its not like most nondinofreak people would really notice. Show them a picture of a torosaurus and they will call it a triceratops anyway. |
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