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RE: Phorusrhacos “wrinkle bearer (jaw)”:

A more recent abstract also suggested a Late Cretaceous evolution of Cariamae:
Bourdon, E. & J. Cracraft, 2011.  *Gastornis* is a terror bird: New insights 
into the evolution of the Cariamae (Aves, Neornithes).  Journal of Vertebrate 
Paleontology 31: 75A.

> Date: Wed, 27 Jun 2012 14:41:44 +1000
> From: tijawi@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Phorusrhacos “wrinkle bearer (jaw)”: Etymology and Meaning
> Ben Creisler <bcreisler@gmail.com> wrote:
> > The article in La Nature theorized that the giant birds may have
> > coexisted with the last of the dinosaurs in South America during the
> > Cretaceous and actively preyed on them, likely contributing to their
> > extinction!
> The idea isn't as off-the-wall as it first sounds. There is a report
> of a possible phorusrhacoid from the Late Cretaceous of Antarctica.
> Or at least some form of cursorial bird, based on an isolated femur
> from the Lopez de Bertodano Formation (although not from the same
> level that yielded _Vegavis_ and _Polarornis_). The femur *might* be
> from a cariamaform (even a phorusrhacoid, see below), and the Lopez de
> Bertodano Formation has been dated to the end of the Cretaceous (I
> don't know how confidently - see Dyke & van Tuinen, 2004).
> In any case... large, cursorial, predatory neornithean birds such as
> phorusrhacoids might well have been around at the end of the
> Cretaceous, up to (and beyond) the end-K catastrophe. If so, these
> birds could have preyed upon small non-avian dinosaurs in the
> aftermath of the impact, and therefore helped hasten the extinction of
> the survivors. You never know.
> Case J., Reguero M., Martin J., and Cordes-Person, A. (2006). A
> cursorial bird from the Maastrictian of Antarctica. Journal of
> Vertebrate Paleontology 26 (3): 48A.
> "A left femur from the early Maastrichtian, Cape Lamb Member of the
> Lopez de Bertodano
> Fm. on Vega Island, Antarctic Peninsula, shows striking similarities
> to modern cursorial
> predatory birds of South America (Seriemas, Cariamidae) and of Africa
> (Secretarybirds,
> Sagittariidae). The size of the Antarctic femur is nearly identical to
> those of both modern
> bird families and thus the Antarctic specimen would be about the same
> size, at around a
> meter in height. The crucial features in demonstrating the habit of
> this Maastrichtian bird
> are: the enlarged and posteriorly prominent tibiofibular crista; the
> laterally expansive lateral
> epicondyle; and the highly planar and vertically oriented fibular
> trochlea. These apomorphic
> features are present in the modern yet unrelated cursorial birds and are 
> equally
> developed in the Antarctic specimen. Considering the proximal femoral
> features, the biogeographical
> location and the presence of phororhacoids in the Eocene of Antarctica, then
> this specimen may represent a taxon which may be ancestral to both cariamids 
> and
> phororhacoids or it is the basal cariamid which is then ancestral to
> the phororhacoids, rather
> than being their descendant."