DinoData

Once again I would like to sing the praises of Dinodata. It's been a while since I've visited the site but I'm glad that I did. Apparently an oviraptor called Ingenia (one who's photo has long eluded me)has been shown to gave numerous impressions of blood vessels on the inside of its brain case, indicating that at least in that group, the brain was snuggly fitting within the skull, much like modern birds and mammals. As for what this evidence indicates in terms of phylogeny its pretty inconclusive if you ask me. The camp that says that oviraptors are within the crown group birds would argue that they inherited their larger brains from their birdy ancestors, where as the group that puts oviraptors in an outgroup relation to birds would argue that birds and oviraptors inherited the larger brain from a common ancestor. I personally like the idea that an ancestor with either a much lower body mass or a dramatic change in bite mechanics (reduces shock transmission to the brain) facilitated the transition to a more closely fitting brain. Still this hypothesis could go either way in terms of phylogeny.