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Re: New paper on fish fingers

Allen Hazen wrote:

> Comment: maybe we shouldn't be too surprised at that. 
> There seems to be an analogous situation at the bottom of the mammal 
> tree: Trithelodonts are more mammalesque in some features, Tritylodonts > in 
> others, and then there's Brazilodon... (Key word: "mosaic 
> evolution".)  My impression is that dinosaur workers are finding 
> something similar at the bottom of birds.
> Maybe it is to be expected that new clades with major
> morphological novelties will arise from "bushes" in which there
> has been extensive "experimentation."

Indeed.  As another example... how else can you explain the situation in early 
turtle evolution?  You have two Late Triassic forms (_Odontochelys_ and 
_Chinlechelys_) which show strikingly different morphologies of the dorsal 
carapace, with both interpreted as incipient.