Photo of the Day #84: Cryolophosaurus

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When I was a kid nearly every dinosaur book and documentary had at least one common phrase that was uttered over and over again; "Dinosaurs have been found on every continent, except Antarctica." By 1986, though, this could not longer be stated as the ankylosaur Antarctopelta oliveroi was discovered, with the large theropod Cryolophosaurus ellioti being uncovered in 1991 (subsequently named in 1994). While its phylogenetic position is still undergoing scrutiny (at present it appears to be the oldest known tetanuran theropod), Cryolophosaurus is impressive as it was a very large (about 20-26 feet long) Early Jurassic predatory dinosaur in a climate that would have been much more temperate than other areas at the time. The site in which Cryolophosaurus was found has also yielded remains of other dinosaurs and fossil plant material at the site, much of it still undergoing study. Not long ago the sauropodmorph Glacialisaurus hammeri was announced in the literature, and there may even be the remains of a larger sauropod dinosaur as well. In just a few short years it seems that we've gone from having no polar dinosaurs to having an abundance (so much so as to start reconstructing the paleoecology of some sites), and I'm sure there's much more to be discovered concerning polar dinosaurs. (The above image was taken at the Maryland Science Museum.)

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Hey guys - thought I could shed a little light on this specimen for you.

This particular skull is 100% reconstructed. The only reconstructed skull which contains cast from the actual fossil is on the Auckland Museum mount in New Zealand.. all others are casts of a 100% original sculpt based on reference.

The cryo skeletons are based on the fossil that was prepared from the original find with the remainder being made up from casts of Albertosaurus. More material has been recovered from subsequent expeditions and might be included in future mounts - this is speculation only however.

I'm sure some will want my credentials... I'm the guy who molded the original skull block as well as a large portion of the remaining fossil. I also did the worlds first cranial reconstruction and appeared with it on The Learning Channel in the documentary "at the ends of the earth" in the series narrated by Jeff Goldblum.

Of all the dinosaurs Ive worked on over the last decade... Cryolophosaurus remains my favourite... Im glad to see people still talking about it.

Cheers!!

Some items of note:

The front end of the skull as shown here is almost entirely reconstructed.

Also, Nathan Smith et al.'s masterful study strongly support Cryolophosaurus as a member of a clade of basal theropods containing Dilophosaurus, Dracovenator, and "Dilophosaurus" sinensis. This clade is basal to the Ceratosauria-Tetanurae split, but crownward to the Coelophysoidea-everybody else split. Although Smith et al. did not assign a name to this clade, "Dilophosauridae" is already available and quite reasonable for this group, so that's what I am calling them.

My lecture notes for that topic are here.

Happy New Year!

That's an excellent photo. I love the contrast between the blues of the background and the yellow-brown of the skull itself. And I find the shape of the crest really fascinating - more like a ceratopsian crest than a theropod's (although I am not of course implying any shared ancestry there!).

Cryolophosaurus came to Anchorage a few years back. Both the original skull and a reconstructed skull + skeleton arrived. The skeleton was obviously from Allosaurus, which deeply saddened me.

Now I've been sucked into Dr. Holtz's lecture notes...

I've been adding taxa and characters to Smith et al.'s Cryolophosaurus analysis. Dilophosaurids definitely seem to be coelophysoids, as Smith et al. left out a lot of coelophysoid characters from Tykoski's thesis which support this. The support for placing Cryolophosaurus and "Dilophosaurus" sinensis in Dilophosauridae seems weak though, and the two taxa often emerge as basal tetanurines instead. This is probably what led to Smith et al. placing Cryolophosaurus there in their earlier SVP abstract.