[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Mesozoic roots of parrots and passerine birds

My 0.02 € on the "Cretaceous parrot jaw"... anyone designing a phylogenetic analysis will have to keep in mind that "loriid" and "oviraptorosaur" aren't the only two possibilities. There are many Cretaceous clades of toothless birds, and their fossil record is bad enough that we hardly know anything about their distribution in space and time or, therefore, their morphological diversity. Off the top of my head, imaginable candidates for close relatives are the confuciusornithids (in particular *Changchengornis* with its slightly hooked beak), so far known _exclusively_ from Konservat-Lagerstätten, *Gobipteryx*, likewise only known from one site, and *Samrukia*, which may be closely related to the much smaller *Patagopteryx* (...no, I don't mean *Patagonykus* this time ;-) ).

 The problem is exacerbated by the dating issue. "Eufalconimorphae"
 are not entirely unreasonable, but Cretaceous? What about
 Close enough to a "missing link" somewhere near the base of
 Eufalconimorphae, but alive and kicking after 50 Ma including a
 mega-extinction and near-complete ecological turnover (and
 carnivorous to boot?) and still very much *looking* like the misssing
 link you'd expect? It works too well in some aspects, and it
 completely sucks in others. Those parts of the tree we *have*
 resolved for good fit together more or less awkwardly, but overall in
 a satisfying way.

IMNSHO, the "dating" is bunk; fortunately, it's tacked on to the end of the study, not an integral part of it, so it can be disregarded without casting doubt on the other results.

Indeed, as I've already mentioned, I think the phylogenetic tree they got is itself evidence for much younger dates. That huge unresolved Neoaves radiation which shows evidence of incomplete lineage sorting (contradictory distributions of retroposons)? That looks like it happend very, very quickly. The only time at which I can imagine such a thing happening is in the empty world after the K-Pg boundary mass extinction.

Thanks a lot for the links. Evidently, somebody has now persuaded the university library of Vienna to use some of its nonexistent funds to buy the 2nd-ranked journal in paleontology (impact factor of 2010: 3.844 -- the JVP had 2.241 and is the 8th-ranked journal in paleontology). Excuse me while I go on a downloading spree that will probably take all week. <bliss>