Download Full Document - Mountain Boomer Music!

26 BULLETIN CARNEGIE MUSEUM OF NATURAL HISTORY NO. 32
anoles except Chamaeleolis). Because Frost and
Etheridge (1989) found Polychncs to be the sister
taxon of the anoles, the presence of palatine teeth
is considered as the ancestral state for Polychroti-
dae. Therefore, if palatine teeth are to be considered
apomorphic for Crotaphytidae, it must be assumed
that Crotaphytidae and Polychrotidae are not sister
taxa. Such a relationship was not supported in the
analysis of Frost and Etheridge (1989) as depicted
in their 12 equally parsimonious unrooted trees.
Therefore, palatine teeth are tentatively considered
to be apomorphic for Crotaphytidae.
All crotaphytids possess pterygoid teeth on the
posteromedial border of the palatine process (Fig.
11). These teeth may form a single row or, late in
ontogeny, exist as a patch. During ontogeny, the
number of pterygoid teeth clearly increases, al-
though there is not a perfect correlation between
number of teeth and SVL and some very large in-
dividuals have relatively few teeth. Additional teeth
are usually added to the posterior portion of the
patch, and in larger individuals, the majority of the
teeth are found posteriorly. In some juvenile and
most adult Crotaphytus, the posterior aspect of the
pterygoid tooth row curves laterally away from the
interpterygoid vacuity (Fig. 1 I), while in Gambelia
the tooth row follows the margin of the vacuity.
Polarization of this character is complicated by the
absence of pterygoid teeth in the families Phryno-
somatidae and Chamaeleonidae and in some Phy-
marurus and Leiocephalus. Furthermore, pterygoid
teeth are often intraspecifically variable and limited
sample sizes for certain outgroup species probably
did not allow them to be coded adequately for this
character. However, in the remaining outgroup taxa
examined, the pterygoid tooth patch was observed
to curve posterolaterally only in Uranoscodon su-
perciliosus, Corylophanes percarinatus, some C.
cristatus, some Laemancttrs serratus. Brachylophus
fasciaius, and Pristidactylus casuhatiensis (see de
Queiroz, 1987, for additional iguanid taxa with pos-
terolaterally curved pterygoid tooth patches). There-
fore, the posterolateral curving of the pterygoid tooth
patch was considered to be the derived state within
Crotaphytidae.
Scleral Ossicles. -The scleral ossicles are thin,
overlapping platelets of bone that form a supportive
ring within the anterior portion of the sclera of the
eye. De Queiroz (1982) found that most iguanian
taxa are characterized by a standard pattern con-
sisting of 14 ossicles, with numbers one, six, and
eight positive (overlapping both of the iyijacent os-
sicles), numbers four, seven, and ten negative (over-
lapped by both of the adjacent ossicles), and the
remaining ossicles imbricating (overlapping one of
the adjacent ossicles, but itself overlapped by the
other). He noted that this pattern is present in Cro-
taphyrus collaris, C. vestigiutn, and Gambelia wis-
lizenii. I have verified his observations for these
species, and report further that the remaining cro-
taphytid taxa are also characterized by this appar-
ently ancestral iguanian condition. A list of speci-
mens for which the scleral ossicles have been ex-
amined is provided in Appendix 7.
Hyoid Appararits (Characters 34-36; Fig. 16). -A
number of differences in the morphology of the hy-
oid apparatus exist between Crotaphytus and Gam-
belia. In Crotaphyrus, the ceratohyals may be greatly
expanded proximally, such that a large hook or pro-
cess is present (processes absent in one of four C.
antiquus). Their development is subject to ontoge-
netic variation and subadults did not have the hook;
therefore, the character was scored only from adults.
In Gatnbelia, the proximal portion of the ceratohyal
may be somewhat compressed; however, well-de-
veloped hooks are absent. This character varies ex-
tensively in the outgroups and was therefore left
unpolarized.
In Gatnbelia, the second ceratobranchials are
short, extending posteriorly for about half the length
of the ceratohyals and first ceratobranchials, while
in Crotaphytus they are longer, extending more than
two-thirds the length of the ceratohyals and first
ceratobranchials (Robison and Tanner, 1962; Fig.
16). The second ceratobranchials of C. dickersonae
are often particularly long and in adult males usually
extend as far posteriorly as do the ceratohyals and
first ceratobranchials. However, this was not treated
as a separate character state because of continuous
variation between the extreme C. dickersonae con-
dition and that present in other Crotaphytus, par-
ticularly in C. collaris. The longer second cerato-
branchials of Croraphytus may function in the de-
pression of their more strongly developed gular
pouch. The outgroups vary continuously in the length
of the second ceratobranchials ran&ng in relative
length from very short in Phymarurus to extremely
elongate in Polychrus, the anoles, and Brachylophus.
Therefore, this character was left unpolarized.
In Crotaphytus. the second ceratobranchials are
in closecontact, although they are not actually fused,
whereas in Gambelia, they may be widely separated