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Re: questions about the Odontochelys study



> I repeat: > Which species on the non-turtle side of the equation?
> 
> +++++++++++++++
> 
> Still wondering: which _species_? (¡primo importante!)

Here's the complete tree of deBraga & Rieppel 1997:

--+--Seymouriadae [double argh!]
  `--+--Diadectomorpha
     `--+--+--Caseidae
        |  `--+--Ophiacodontidae
        |     `--+--Edaphosauridae
        |        `--+--Gorganopsia [argh!]
        |           `--Cynodontia
        `--+--+--Millerettidae
           |  `--+--+--Lanthanosuchidae
           |     |  `--*Acleistorhinus*
           |     `--+--*Macroleter*
           |        `--+--+--Procolophonidae
           |           | `--Owenettidae
           |           `--+--*Bradysaurus*
           |              `--+--*Scutosaurus*
           |                 `--*Anthodon*
           `--+--Captorhinidae
              `--+--*Paleothyris*
                 `--+--Araeoscelidia
                    `--+--*Claudiosaurus*
                       `--+--Younginiformes
                          `--+--+--Choristodera
                              |  `--+--Prolacertiformes
                              |     |--Archisauriformes [argh!]
                              |     `--+--Rhynchosauria
                              |        `--*Trilophosaurus*
                              `--+--+--Kuehneosauridae
                                 |  `--+--Rhynchocephalia
                                 |     `--Squamata
                                 `--+--Testudines
                                    `--+--Eosauropterygia
                                       `--*Placodus*

Synapomorphies for Testudines, Eosauropterygia (which of course is what other 
people call Sauropterygia) and *Placodus*:

unambiguous:
8(1): Choana curving caudomedially so that the long axis would form an angle of 
about 45° with the medial surface of the maxilla. Also found in Pareiasauria, 
Gorgonopsia, and Rhynchosauria.
64(1): Parasphenoid compressed into a nearly square element where its length is 
never more than 20 % of its narrowest transverse width. Also found in 
(*Scutosaurus* + *Anthodon*), *Claudiosaurus*, "Archisauriformes" [argh!], and 
Therapsida.
80(1): Transverse flange [of the pterygoid, most likely] directed rostrally at 
an angle of less than 45° to the "parasagittal axis" [sagittal plane, that is], 
and lateral and rostral portions of the transverse flange merging smoothly, 
forming a curved rostrolateral margin. Also found in Pareiasauria, 
Choristodera, *Trilophosaurus*, and Squamata.
116(0): Mineralized sternum absent. Also found everywhere else except in the 
rest of Diapsida and in Therapsida (it's a reversal).
121(1): Scapula participating in border of coracoid foramen. No comment given, 
so it's apparently unique in the whole data matrix.
123(1): Humeri twisted by 20° or less. Also found in *Anthodon*, Cynodontia, 
and Squamata.
143(1): Distal condyles of femur reduced = almost indistinguishable from the 
distal end of the femur. Also found in *Claudiosaurus*, Choristodera, and 
Cynodontia.
162(0): Width of distal end of humerus > 1/3 total length of the entire bone. 
Also found everywhere else except in the rest of (*Paleothyris* + Diapsida) 
(with *Claudiosaurus* as the exception from the exception), *Macroleter*, 
*Owenetta*, and Cynodontia (it's a reversal).
163(0): Total length of carpus or [!] tarsus > 60 % of the 4th digit [including 
the metapodial]. Also found everywhere else except in Millerettidae, 
Cynodontia, and (*Paleothyris* + Diapsida) (it's a reversal).

ambiguous:
158(2): Loss of "both" centralia in the tarsus (apparently centralia 1 and 2 
are meant, with 4 being part of the astragalus and 3 having been lost earlier 
or having fused to distal tarsal 4). This may either be an autapomorphy of 
Procolophonia and Lepidosauromorpha with a reversal to state 1 in 
Kuehneosauridae, or an autapomorphy of Procolophonia, (Testudines + 
Sauropterygia), and Lepidosauria (both cases require three steps). DeBraga & 
Rieppel use the name Procolophonia for (Pareiasauria + (Procolophonidae + 
Owenettidae)).

If nothing else, this list gives an idea of how much homoplasy we have to deal 
with!

You'll notice that the next node to the left of the above is Lepidosauromorpha. 
I'll post its autapomorphies next.
-- 
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