Nanotyrannus Nomore!?

Nanotyrannus is everyone’s favorite tyrannosaur, as long as it’s right behind the big guy, Tyrannosaurus, itself. It’s been lovingly depicted and aggressively championed by such notable figures as Robert Bakker, and supported less enthusiastically but no less masterfully by Philip Currie. Nanotyrannus was the name given to Gorgosaurus lancensis (Gilmore, 1946) by Bakker, Williams and Currie in 1988 for an elongated, narrow-snouted skull (CMNH 7541). 40 years later, the peculiar morphology of the skull, with its broad boxy posterior end and the thin snout, slender and narrow blade-like teeth, and greater numbers of them, implied that it might be very distinguishable from Gorgosaurus, and in fact from Tyrannosaurus to which it was compared favorably, resulting in the “tiny tyrant,” Nanotyrannus being given to replace Gorgosaurus, thus Nanotyrannus lancensis.

Notable News for Nanotyrannus

Enjoy this allusory introduction to a forthcoming post. While the news is out about this paper, and it’s “available,” the paper is unpublished and the version “available” is a proofed manuscript (containing various revision marks and formatting structure that I will not hold it as the “final” version — but is available from the Witmer Lab for free nonetheless, here).

Update: I was unaware that the final (as in identical to “print”) version of the online copy was available for free from Informaworld, and is here. (Like the link above, this is the actual pdf link, so click at your own peril — it may take time to load.) I’m still curious about waiting for the print copy (the “formal” version of the paper) to be published, although I suspect this is also the case.

Why Don’t Tyrannosaurs Have All Bananas For Teeth?

Shortly after my last post, a little discussion ensues, and I realize there is a little more I should say here on the subject.

In a message sent to the Dinosaur Mailing List (the original of which can be found here [when the link is available!]), I wrote:

Tyrannosaurs Don’t All Have Bananas for Teeth

One of the things that I’ve been itching to do is generate a database of variation in dental series across a variety of taxa, virtually most if not all variations of archosaurs and beyond. This is to assess the quality of jaw shape with tooth shape, tooth function, jaw function (not always overlapping), and diet. Fun stuff … for me. It would be incredibly repetitive, boring, and time-consuming research, and probably something that would take me years of world-hopping to achieve (although I can work from casts just as well as real specimens).

Why?

The Aussie Tyrant – or Is It?

I spent some time a little bit ago rehashing an old premise of mine, that of the growing “primitive” tyrannosauroids and the grades they make. Of these, there are “true” tyrannosauroids (tyrants, roughly corresponding to Tyrannosauridae), “middle” tyrannosauroids (despots, mid-sized to small Tyrannosauroidea), and the precursor forms which seem to stem from very small, gracile, and compsognathid-like coelurosaurs (peons, which may or may not fall into Tyrannosauroidea). It should be noted that under the currently accepted forms for the usage of the term, Tyrannosauroidea contains all theropods that are closer to Tyrannosaurus rex than to, say, a bird, a dromaeosaurid, a troodontid, an allosaur, etc. The explicit definition is flexible, but it basically means if its on the lineage toward a tyrannosaurid like T. rex, then it IS a tyrannosauroid.

Tyrants, Despots and Peons

The origin and evolution of Tyrannosauroidea [1] is one of the interesting puzzles in theropod phylogeny (the only one more fascination (with all due apologies to Tom Holtz) [2]. Inclusion of tyrannosaurids is a no-brainer, but the origin of tyrannosaurs has found itself in strange company, including rooted close to the origin of Maniraptora (oviraptorosaurs, dromaeosaurs, birds, and troodontids, and a few other odds and ends) [3], as the sister taxa to ornithomosaurs [4], or as the most basal lineage of Coelurosauria [2], to name just a few.