Re: New papers

[Jon Barber <augray@sympatico.ca>]

At 12:06 PM 10/13/2005 -0500, Tim Williams wrote:

> First up, a salvo against the BANDits...  However, Feduccia &c appear now 
> to be arguing that birds and maniraptorans are indeed closely related, but 
> that they are NOT theropods or dinosaurs.  This is a load of codswallop, 
> of course, but it may require a new tactic in refuting their arguments 
> (e.g., demonstrating that you cannot remove Maniraptora from the 
> Theropoda, any more than you can take Aves out of Maniraptora).
>
> Chiappe, L.M. (2004). The closest relatives of birds.  Ornitologia 
> Neotropical. 15(Suppl. S): 101-116
>
> ABSTRACT: "The origin of birds, the clade originating from the common 
> ancestor of the Late Jurassic _Archaeopteryx_ and extant birds, has been 
> at the center of a heated debate throughout the history of evolutionary 
> biology. Although many disparate hypotheses of bird origins have been 
> proposed in the last two centuries, an overwhelming consensus exists in 
> support of the idea that birds evolved from maniraptoran theropod 
> dinosaurs. Osteological support for this hypothesis is plentiful. The 
> skeletons of such maniraptoran dinosaurs as dromaeosaurids, troodontids, 
> and oviraptorids, share a great deal of similarity with those of birds. In 
> addition, a series of spectacular discoveries in the last decade has 
> provided new lines of evidence that supplement the already overwhelming 
> osteological data. This recent evidence is derived primarily from the 
> study of egg morphology and integumentary anatomy but also includes 
> behavioral inferences based on a handful of rare fossils. These 
> discoveries have documented the presence of feathers, brooding behavior, 
> autochronous ovideposition, and other avian attributes among basal 
> maniraptoran dinosaurs. The available evidence strongly supports the 
> classification of birds within theropods and indicates that many avian 
> attributes previously thought to be unique to birds (from brooding 
> behavior to flight) first evolved among maniraptoran dinosaurs. Although 
> dissenters of the Maniraptoran hypothesis of bird origins have countered 
> by highlighting temporal and developmental limitations, these criticisms 
> are clearly spurious. The most frequently voiced arguments, the so called 
> "temporal paradox" and the homology of the digits of the avian hand, are 
> tainted by logical inconsistencies. Perhaps the most important is the fact 
> that these dissenters have been unable to produce alternative phylogenetic 
> hypotheses that could explain, within the methodological framework of 
> cladistic parsimony, the vast amount of similarity between non-avian 
> theropods and birds."

Available on-line at http://www.radio-luma.net/pdf/2004Chiappe2.PDF