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Post by Infinity Blade on Dec 31, 2014 21:38:39 GMT 5
I have a question regarding the dentition of Daemonosaurus chauliodus.  ^Above is a reconstruction of Daemonosaurus's skull with the commonly believed proportionately large, protruding teeth.  © @ Qilong (Jaime A. Headden)qilong.wordpress.com/2013/05/16/a-skull-reconstruction-for-daemonosaurus/^Then there's a skull reconstruction by Jaime A. Headden with reasonably-sized teeth and an explanation as to why he thinks this is the case (he suspects the teeth came out of their sockets). Which do you guys believe is more likely? |
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Post by Godzillasaurus on Jan 2, 2015 0:26:19 GMT 5
Wow. That think does not look dinosaurian at all...
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Post by theropod on Jan 2, 2015 0:49:05 GMT 5
This thing’s definitely an oddball taxon. That extremely short skull and large orbit looks like paedomorphism.
I’d say the shorter teeth are compelling, but I also think it’s a little premature to automatically consider every theropod tooth that looks extremely long-crowned to have just slipped out of its socket, as there may well be real theropod teeth that are that long proportionately. If anything, only detailed study of the fossil will give us clarity.
Also it’s a bit strange Headden routinely assumes long teeth to simply have slipped out of their sockets and restores them as shorter, but in his Dilophosaurus he intentionally left parts of the roots exposed.
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Post by Godzillasaurus on Jan 2, 2015 3:06:26 GMT 5
It seems vaguely similar to dilophosaurus to be honest, albeit unrelated
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Post by theropod on Jan 2, 2015 4:10:13 GMT 5
Well, that’s where it gets interesting:
Daemonosaurus indeed has a non-carinated premaxillary (and anterior dentary) dentition, and a diastema in the upper toothrow, just like Tawa and Coelophysoidea.
Sues et al. 2011 found it to be a basal theropod less derived than neotheropoda but more derived than Tawa, Eoraptor and Herrerasauridae. T. hallae itself was originally (Nesbitt et al. 2009) found to be a non-neotheropod and coelophysoidea to be non-monophyletic, but Martínez et al. 2011 recovered it within a monophyletic coelophysoidea (albeit with weak support), and Sues et al.’s analysis didn’t include Eodromaeus because they had no access to the specimen. So it’s possible that with this important taxon included, Daemonosaurus would actually turn out as a coelophysoid, just like Tawa.
References:
Martínez, Ricardo N.; Sereno, Paul C.; Alcober, Oscar A.; Colombi, Carina E.; Renne, Paul R.; Montañez, Isabel P.; Currie, Brian S.: A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea. Science, Vol. 331 (2011); 6014; pp. 206-110
Nesbitt, Sterling J.; Smith, Nathan D.; Irmis, Randall B.; Turner, Alan H.; Downs, Alex; Norell, Mark A.: A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs. Science, Vol. 326 (2009); 5959; pp. 1530-1533
Sues, Hans-Dieter; Nesbitt, Sterling J.; Berman, David S.; Henrici, Amy C.: A late-surviving basal theropod dinosaur from the latest Triassic of North America. Proceedings of the Royal Society B, Vol. 278 (2011); pp. 3459-3464
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