Biology Reference
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that it is impossible to distinguish them from apparently isodont specimens of
these forms
…
.” Similarly, Rossman (1961) noted that
T. sauritus
(eastern ribbon
snake) and
T. proximus
(western ribbon snake) had the greatest number of maxil-
lary teeth among the genus. He also reported that these taxa exhibit maxillary teeth
that increase in size only slightly posteriorly, but the posteriormost two or three teeth
abruptly increase in size. Fry et al. (2008) described the maxillary teeth of
T. elegans
as smooth (without grooves).
Gross examination of the maxillary teeth of eight live specimens of
T. sirtalis sirtalis
and three live specimens each of
T. proximus
and
T. marcianus
(checkered garter snake or
Marcy's garter snake) suggested nearly imperceptible differences in maxillary tooth size
among the specimens examined (SAW, personal observations). Close examination of a
T. sirtalis
skull showed no size differences among the maxillary dentition. The maxillary
teeth are recurved, equal in size, and ungrooved (
Plate 4.54B
). The maxillary dentition
appears very similar to that of a typical non-front-fanged colubroid without any special-
ized dentition [e.g., Taiwan beauty snake,
Orthriophis
(
Elaphe taeniura friesi
Tiedemann
and Grillitsch, 1999)
taeniurus
Cope, 1861; see
Plate 4.54C
; in addition, this species
lacks a Duvernoy's gland]. Two young adult live specimens of
T. e. vagrans
exhibited
two or three slightly but perceptibly enlarged posteriormost maxillary teeth (SAW, per-
sonal observations). These observations were concordant with those from examination of
the maxilla of a
T. e. vagrans
specimen (
Plates 4.54B and 4.77
). The posteriormost max-
illary teeth are slightly enlarged, smooth, and without perceptible grooves (
Plates 4.54B
and 4.77
).
(B)
(C)
Plate 4.54
(B) Comparison of maxillae of
Thamnophis sirtalis sirtalis
and
Thamnophis
elegans vagrans
. The posterior maxillary teeth of
T. s. sirtalis
have no gross enlargement
or grooves (main panel), while several of the most posterior maxillary teeth of
T. e. vagrans
(inset panel) are slightly enlarged but also lack grooves.
(C) Skull and maxilla of the Taiwan beauty snake (
Orthriophis taeniurus
).
Formerly
synonymized with the genus
Elaphe
(rat snakes), these colubrine snakes lack any significantly
specialized dentition as well as Duvernoy's glands. Several subspecies of
O. taeniurus
are
popular in private collections.
Plate 4.54B
,
T. sirtalis sirtalis
, AMNH #70096;
T. e. vagrans
,
AMNH #R148051, photos copyright to Arie Lev;
Plate 4.54C
, photo copyright to Javier José
Carrasco Araújo.
