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Re: New papers



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