Re: questions about the Odontochelys study

[David Marjanovic <david.marjanovic@gmx.at>]

> Was wondering which species the authors used when they say that  turtle 
> blood tests link them with 'diapsids'?

Several. Also, not just any diapsids: either as the sister-group of 
Archosauria or as the sister-group of Crocodylia.

And a phylogenetic analysis of sequence data is not a "blood test".

> Was wondering which species Rieppel used when he linked turtles to 
> lepidosaurs or squamates and sauropterygians?

Mostly *Proganochelys*, IIRC.

(Which, incidentally, is not trivial to interpret. Kordikova 2002 claims to 
have discovered postparietals and tabulars in the skull, both never seen 
before and both supposed to be absent.)

> How many millions of years link turtles to their closest known sister 
> taxa?

Depends on what those are, obviously. Euryapsids appear sometime around the 
Early-Middle Triassic boundary, lepidosaurs in the Middle Triassic, 
crown-group archosaurs around the Early-Middle Triassic boundary (probably 
earlier), procolophonoids in I think the Late Permian, and pareiasaurs in 
the Middle Permian.