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Re: questions about the Odontochelys study



I forgot to mention that deBraga & Rieppel don't mean the crown-group by 
"Testudines", but the apomorphy-based clade that is now mostly called 
Testudinata.

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

Here goes:

unambiguous:
19(0): Preorbital and postorbital parts of skull have equal length "when the 
ratios are taken between snout tip and posterior limit of occiput" -- whether 
the rostral or the caudal margin of the orbit, both, or the middle of the orbit 
are taken is not mentioned, however. Also found everywhere else except in the 
rest of Diapsida (with Rhynchosauria as the exception from the exception), in 
Lanthanosuchidae, and in (Ophiacodontidae + Cynodontia) (it's a reversal).
20(1): Prefrontal-palatine contact. Also found in Rhynchosauria and what the 
authors call "Parareptilia".
51(3): Lateral temporal fenestra ventrally open. Also found in *Claudiosaurus* 
and Prolacertiformes, and reversed in the turtles. More recent research (with 
better taxon sampling) has shown that this is in fact an autapomorphy of a 
clade almost as large as Diapsida, and reversed several times, for example in 
Archosauriformes.
89(1): Lateral exposure of angular reduced to narrow sliver. Also found in 
Rhynchosauria.
133(1): Thyroid fenestra. Also found in Therapsida and some members of 
Prolacertiformes. (I have to check the turtles.)
146(1): Perforating artery of pes passes between tibia and fibula (rather than 
between astragalus and calcaneum). Also found in Therapsida and Rhynchosauria.
152(1): Loss of distal tarsal I. Also found in some members of 
"Archisauriformes" and Prolacertiformes; reversed in some rhynchocephalians and 
in the turtles (though, strangely, this is not listed as a turtle autapomorphy).

ambiguous:
11(1): Tall rostrodorsal process which effectively doubles the height of the 
maxilla. Either an autapomorphy of Lepidosauromorpha and (Rhynchosauria + 
*Trilophosaurus* + "Archisauriformes"), or one of the diapsid crown-group that 
was reversed in Choristodera and part of Prolacertiformes. Also found in 
Ankyramorpha ( = "parareptiles" except Millerettidae), Caseidae, and 
(Sphenacodontia + Cynodontia).
29(1): Postfrontal participates in upper temporal fenestra. Either an 
autapomorphy of Lepidosauromorpha and Younginiformes, or a synapomorphy of 
these with a reversal in Archosauromorpha.
42(3): Loss of the quadratojugal. Either an autapomorphy of Lepidosauromorpha 
with reversals in Rhynchocephalia, some members of "Eosauropterygia" and the 
turtles, or... they don't say what the other possibility is, but from 
eyeballing the tree it must be four independent losses in Kuehneosauridae, 
Squamata, *Placodus* and the other members of "Eosauropterygia" -- four steps 
either way. However, *Placodus* does too have a quadratojugal, and a mighty 
huge one that makes up almost the entire (upper) temporal bar (Pinna 1993 
finally found the suture to the squamosal which is already known in several 
other placodonts).
49(2): Pineal foramen in the rostral half of the parietals. Either an 
autapomorphy of Lepidosauromorpha with reversals in Squamata, some 
rhynchocephalians, and some "eosauropterygians" and loss of the pineal foramen 
(state 3 of the same character) in turtles and some squamates, or an 
autapomorphy of "Lepidosauriformes" and "Sauropterygia" ( = Euryapsida) -- in 
which case the _presence_ of the foramen is a reversal in the abovementioned 
two clades and its absence an autapomorphy of the diapsid crown-group. 
Furthermore also found in Caseidae, Cynodontia, and all "parareptiles" except 
Millerettidae and (by means of reversal) part of Lanthanosuchidae.
65(1): Tubera on the ventral surface of the basioccipital present. Either an 
autapomorphy of Lepidosauria, *Trilophosaurus*, Prolacertiformes, and 
(Owenettidae + Procolophonidae), or an autapomorphy of the latter clade and of 
the diapsid crown-group with reversals in Rhynchosauria and Choristodera.
76(1): Palatal process of the pterygoid does not reach rostral margin of 
palatine. Apart from a confusing distribution among "parareptiles" that I'll 
spare us, and a presence in *Paleothyris* and in (Edaphosauridae + Therapsida), 
this is either an autapomorphy of Lepidosauromorpha, Choristodera, and 
"Archisauriformes" or one of the diapsid crown-group with reversals in 
Prolacertiformes, Rhynchosauria and *Trilophosaurus* (the latter two probably 
come out as sister-groups in some trees).
78(2): Loss of teeth on the "T-flange" [transverse flange?] of the pterygoid. 
Either an autapomorphy of Lepidosauria and (Rhynchosauria + *Trilophosaurus*), 
or one of the diapsid crown-group with reversals in Choristodera and within 
"Archisauriformes" and Prolacertiformes; in either case also an autapomorphy of 
Therapsida and of (Procolophonidae + Owenettidae).
107(1): Loss of dorsal intercentra. Either an autapomorphy of Lepidosauromorpha 
and Choristodera, or an autapomorphy of the diapsid crown-group with a reversal 
in what the authors call "Archosauromorpha" ( = Archosauromorpha without 
Choristodera). BTW, the nomenclature in this paper is an unmitigated disaster, 
and I don't mean the extremely frequent misspellings.

Any more questions? :-)
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