Tuesday, August 26, 2008


Dinosauriforms like Silesaurus and Eucoelophysis and that...you know...hopping one (lower left, above) don't form a coherent group, right? They're the rhamphorhynchoids of the dinosaurs, yes? That is, they form a paraphyletic grade of stepwise forms leading from...something...to Dinosauria, correct? Have there been any large-scale studies of "dinosauriforms" as a whole?


Nick Gardner said...

I think you've confused "dinosauriform" with "non-dinosaurian dinosauriforms". Expect our understanding of these forms to improve in the next few years as more specimens are published from the Triassic.

Zachary said...

Yeah, I meant "non-dinosaurian dinosauriforms." It's so awkward. It's like placing "non-avian" in front of "theropod" to talk about any theropod that's NOT a bird. There should really be some informal terminology to deal with these broad categories.

Brad said...

Yes, there have been several comprehensive phylogenetic studies of basal dinosauriforms, and yes, they always turn out to be paraphyletic. Here is one such study published in Geodiversitas ("A review of the systematic position of the dinosauriform archosaur Eucoelophysis baldwini", link opens as free PDF). The journal Historical Biology recently published a special issue (vol. 19, no. 1) on the 1st Symposium on Early Dinosaur Evolution, which contains mostly relevant articles. The Journal of Systematic Palaeontology has also featured dinosauriforms lately (see Langer & Benton in vol. 4, no. 4).