Wednesday, August 6, 2014

Hand Transition

There is a group of researchers and academics (eg. Feduccia et al) that makes a very strong case that birds did not evolve from dinosaurs.

One important aspect of their argument is the discrepancy in digits (fingers) between dinosaurs and modern birds. The evidence indicates that birds have digits II-III-IV while dinosaurs have I-II-III.

I agree with the researchers and academics that birds did not evolve from dinosaurs.
I go a step further and suggest that the ancestors were pterosaurs.
Pterosaur hands and basal paraves hands are such that a very straightforward transition is possible.

Note that David Peters make an interesting case for the idea that the Yi qi "styliform element" is a displaced radius and ulna.

Dinosaur hand transition reference:,d.aWw

Also see the July 30 post.
New studies by Larsson and Wager, and by Feduccia and Nowicki of the embryogenesis of birds undisputedly show Anlagen for five fingers. This has important implications. First, the early presence of digit I, and its later disappearance, indicate that the evolutionary reduction of digits occurred via developmental arrest followed by degeneration. Second, it shows that the digits in the wings of birds develop from Anlagen II–IV. This suggests that the hypothesized descent of birds from theropods might be problematic, because theropods are assumed to have digits I–III.

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