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20 BULLETIN CARNEGIE MUSEUM OF NATURAL HISTORY NO. 32
This ridge bears a posterior projection in Crotaphy-
tus that overlaps the strong vertical crest of the
transverse process. The ridge does not bear a strong
posterior projection in Ga~rzbelia, instead being
straight or nearly so. Presence or absence of a pos-
terior projection of this ridge are coded as separate
character states. However, there is much variation
in the outgroups and this character could not be
polarized.
The ectopterygoid also bears a strong posterolat-
eral process that is sutured to a similar process of
the jugal. Together they form the tubercle that pro-
jects posterolaterally just beyond the termination of
the maxillary tooth row (see description of jugal
above).
Parabasisphenoid (Character 22; Fig. 1 1 ).-Pro-
jecting anteriorly from the basisphenoid is the long,
blade-like parasphenoid process. Although this is a
separate osseous element, it is fused with the basi-
sphenoid in postembryonic crotaphytids and, fol-
lowing Jollie (1 960:fig. 3), they are here treated as
a single element, the parabasisphenoid.
The posterior suture of the parabasisphenoid with
the basioccipital differs between Gambelia and Cro-
taphyrus. In Gambelia, the parabasisphenoid bears
long posterolateral processes that extend to the
sphenoccipital tubercles. These processes are absent
or extend only slightly beyond the transverse plane
of the parabasisphenoid-basioccipital suture in most
Croraphytus examined (Fig. 1 l), although they may
occasionally reach the base of the lateral process of
the basioccipital. The posterolateral processes never
were observed to reach the sphenoccipital tubercles,
although they nearly reached the tubercle in two of
29 C. collaris (LLG 62, REE 2948).
The majority of the outgoup taxa have long pos-
terolateral processes of the parabasisphenoid that
reach or nearly reach the sphenoccipital tubercles.
Exceptions occur within the families Phrynosoma-
tidae, Chamaeleonidae, Tropiduridae, and Poly-
chrotidae. In Phrynosomatidae, short processes are
present in Petrosaurus. Uta, Urosaurtcs graciosus,
and Sator grandaerus (but not Sceloportcs, at least
those examined here; Appendix l), while in Phg7-
nosoma and the sand lizards they are long. There-
fore, short processes may be an additional syna-
pomorphy for Petrosaurus plus the Sceloporus group,
with a reversal in Sceloporus.
Within Chamaeleonidae, short processes are pres-
ent in Leiolepis belliana, but not Uromastyx or the
basal agamines Physignathus lesueurii and Hydro-
saurus amboiensis. Within chamaeleonines, Broo-
kesia stump$? has short processes, while all of the
remaining chamaeleonines examined (Appendix 1)
except Chamaeleo kersrenii have long processes. In
C. kersrenii, the basioccipital is displaced forward
by the exoccipitals such that it does not form the
ventral portion of the occipital condyle. As a result,
the basioccipital tubercles are found on the exoc-
cipitals rather than the basioccipital. Thus, the ho-
mology of the posterolateral processes (or lack there-
of) of this species is questionable.
In tropidurids, the processes are short in Cten-
oblepharys, Liolaemus, and some Lciocephahcs (short
in L. barahonensis, L. carinatus, L. lunatus, L. tna-
cropus, and L. psammodromus; long in L. green-
tvayi, L. melanochlorus, L. personatus, L. schrei-
bersi. L. sricrigasrer. and L. vinculum), but long in
all of the Stenocercini and Tropidurini examined
(Appendix 1) except T. spinulosus and T. tnelano-
pleurus, which are nonbasal taxa (Frost, 1992).
Within polychrotids, the processes are short in
Pristidacrylus, Diplolaemus, Leiosaurus, the anoles,
the para-anoles (intraspecifically variable in Uros-
trophus vautieri), and some Polychrus acutirostris
(but not P. marmorarus), but long in Enyalius.
Long posterolateral processes represent the an-
cestral condition in Hoplocercidae, Opluridae, Cor-
ytophanidae, Iguanidae, and Chamaeleonidae, and
the polarity of this character is equivocal for Phry-
nosomatidae and Tropiduridae (but long processes
may be ancestral for Tropiduridae). It is most par-
simonious to assume that short posterolateral pro-
cesses were present in the common ancestor of Po-
lychrotidae. Thus, the presence of short posterolat-
eral processes are treated as the derived state within
Crotaphytidae.
Additional intergeneric variation was also ob-
served in the parabasisphenoid. At the anterodorsal
end of the basisphenoid is a depression, the sella
turcica, that houses the pituitary gland. In adult Cro-
taphytus, the sella turcica usually is elevated such
that in lateral view, it is visible above the quadrate
process of the pterygoid. In Gambelia, the sella tur-
cica is more depressed and is rarely visible above
the quadrate process. However, continuous varia-
tion exists in this characteristic and it was omitted
from the phylogenetic study.
MANDIBLE
Denrary (Fig. 13, 14). -In many iguanian lizards,
the dentary is tubular anterior to the splenial and