Sunday, June 27, 2010

Building upon the ideas of others

I have built upon the ideas of such people as Gregory Paul and Stephen Czerkas. For example, Paul, over 20 years ago, proposed some of the ideas I have been expressing:
From Gregory Paul:
"Paul proposed that some of the bird-like feathered theropods were winged fliers, and that others were secondarily flightless, an idea supported by some fossils from China."

I am hypothesizing that the bird-like feathered creatures are the winged fliers that Paul hypothesized.

I am also saying that pterosaurs were the ancestors of the primitive winged fliers (Dromaeosauridae and Enantiornithes etc). Paul did not go that far, but the following is VERY interesting:
"I've noted that the pterosaur-like tails of dromaeosaurs are probably pterosaur-like (with hyperelongated distal prezygapophyses and chevrons) because the tails evolved in fliers. The tail form is, after all, not present in any unambiguous nonfliers. A prediction of this hypothesis is that there should be avepods more derived than Archaeopteryx with long, dromaeosaur-like tails. Cryptovolans [a Dromaeosauridae] fits this bill to a tee. In Nature the description of the new basal bird Jeholornis states that its tail has "unexpected elongated prezygopophyses and chevrons, resembling that of dromaeosaurids." Unexpected only if one is locked into the conventional hypothesis. Yet again a prediction of the neoflightless hypothesis is fulfilled. Birds did experience a flight stage in which the tail functioned in the same manner as long tailed pterosaurs." (G. Paul)

From Stephen Czerkas:
-->"Czerkas also believed that Cryptovolans [a Dromaeosauridae] may have been able to fly better than Archaeopteryx, the animal usually referred to as the earliest known bird. He cited the fused sternum and asymmetrical feathers, and argued that Cryptovolans has modern bird features that make it more derived than Archaeopteryx. Czerkas cited the fact that this possibly volant animal is also very clearly a dromaeosaurid to suggest that the Dromaeosauridae might actually be a basal bird group, and that later, larger, species such as Deinonychus [another Dromaeosauridae] were secondarily flightless (Czerkas, 2002)."
"Others, such as Stephen Czerkas and Larry Martin have concluded that Caudipteryx [an Oviraptor] is not a theropod dinosaur at all.[16] They believe that Caudipteryx, like all maniraptorans, is a flightless bird, and that birds evolved from non-dinosaurian archosaurs [eg. pterosaurs].[17]"

And of course the work of Larry Martin, John Ruben and Alan Feduccia has been immensely helpful.

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