Halbred's Paleo-News Thread

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Halbred:
Looks more like Carnotaurus!

But yeah, I love it! :-D

Halbred:
You can go ahead and prune two names off the pachycephalosaur family tree--it turns out that Dracorex hogwartsia and Stygimoloch spinfer represent the juvenile and subadult (respectively) of Pachycephalosaurus wyomingensis.

Horner and Goodwin came to this conclusion after realizing that all three genera had horns in the same places, and that the bone histeology of Dracorex conforms to that of a juvenile animal, while Styigmoloch is more or less a "teenager." Taken together with the fact that all three are known from the same formation and time (Hell Creek), and you've got a growth series!

So the short version: What were once three genera have been shrunk down to ONE.

That has implications for dinosaur diversity at the end of the Cretaceous in the Hell Creek formation. Nanotyrannus is probably a juvenile Tyrannosaurus, too, and at SVP this year, one presenter suggested that Torosaurus represents an old growth stage of Triceratops. If all this is true, then dinosaur diversity plummeted at the end of the Cretaceous in North America, well before the comet hit.

But more interestingly, it shows that pachycephalosaur skulls were extensively remodeled during growth, just like ceratopsians. As the two groups are usually united in a monophyletic Marginocephalia, this kind of transformative growth could be a synapomorphy of that group.

It's a brave new world. Download the paper FREE from here:

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007626

that Baby guy:
What about the feathers?

Halbred:
...What about the feathers?

that Baby guy:
I dunno. Feathers seemed like a cheap maneuver to reinvigorate the general public's interest in dinosaurs. They didn't realize that dinosaurs don't need feathers to be cool, and instead, it just makes them look like they're at a Shakespearean costume ball.

So far, feathers haven't been mentioned, so I'm trying to make sure this dinosaur is awesome and not some kind of nancy-boy dinosaur for widespread disinterest.

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