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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
> You'll notice that the next node to the left of the above is
> Lepidosauromorpha. I'll post its autapomorphies next.
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
89(1): Lateral exposure of angular reduced to narrow sliver. Also found in
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).
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
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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