THE EVOLUTIONARY HISTORY AND PHYLOGENETIC RELATIONSHIPS OF THE SUPERFAMILY PLATANISTOIDEA - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 472

present on the holotype of Prepomatodelphis korneuburgensis (see Barnes, 2002b:
Figure 2b; 2006:40, character 43, and Figure 5).
44. Nuchal crest relatively low, and not elevated significantly above the adjacent bones
of the posterior part of the facial region [0]; or thickened dorsoventrally and elevated
above the adjacent maxillary and frontal bones [1]. The derived character state is
present on a referred specimen of Zarhachis flagellator (see Kellogg, 1926:pls. 1-4;
Barnes, 2006:40, character 44; and Figure 9 herein).
45. Crowns of teeth relatively broad and wide anteroposteriorly at the base, the width at
the base of the crown being at least one-half of the crown height [0]; or tooth crowns
dorsoventrally elongate, slender, with pointed apices, the width at the base of the
crown being less than one-third of the crown height [1]. The derived character state
is exemplified by a referred specimen of Zarhachis flagellator (see Kellogg, 1924:
pls, 1-3; and Figure 9B herein) (character defined by Barnes, 2006:40, character 45).
An exception to this is the acquisition of secondary heterodonty by Recent Platanista
gangetica (see explanation of character 62 following; see specimens illustrated by
Van Beneden & Gervais, 1868-1880:pl. XXXI, Figure 1; Figures. 10D and 11
herein).
46. Roots of teeth conical, elongate, and implanted nearly straight into the rostrum and
the dentary [0]; or apices of the roots of teeth expanded anteroposteriorly, and in
some taxa curved posteriorly [1]. The derived character state was described by
Barnes (2006:40, character 46) and is present in Recent Platanista gangetica (see
Van Beneden & Gervais, 1868-1880:pl. XXXI, Figure 1; and see Figure 11 herein).
47. Posterior end of premaxilla relatively narrow and not significantly expanded
transversely [0]; or posterior end of premaxilla much expanded transversely [1]. The
derived character state was described by Barnes (2006:40, character 47), and is
exemplified by the holotype of Prepomatodelphis korneuburgensis (see Barnes,
2006: Figure 4) and by a referred specimen of Zarhachis flagellator (see Kellogg,
1926:pl. 2; and see Figure 9 herein).
48. Nasal bones, whether elongate or shortened, of typical width [0]; or nasal bones
much narrowed transversely [1]. The derived character state was described by
Barnes, 2006:40-41, character 48), and is present on the holotype of Allodelphis
pratti (specimen illustrated as Figure 1A herein; by Wilson, 1935: Figure 1; and by
Barnes, 2006: Figure 1).
49. Supraorbital maxillary crest not developed on dorsal surface of supraorbital
process [0]; or supraorbital crest (approximately anteroposteriorly aligned) present
on dorsal surface of the maxilla on the supraorbital process [1]. The derived character
state was described by Barnes, 2006:40, character 49, and is illustrated by Van
Beneden & Gervais, 1868-1880:pl. XXX, Figure 1; pl. XXXI, Figures 2, 2a, 9, 9a; by
Kellogg, 1926: pl. 2; and in Figures 9 and 11 herein).
50. Rostrum cross section not dorsoventrally flattened [0]; or rostrum dorsoventrally
flattened so that for at least the proximal two-thirds of its length its transverse width
is greater than its dorsoventral height [1]. The derived character state is present in
such pomatodelphinine platanistids as the species of Prepomatodelphis, Zarhachis,
and Pomatodelphis (see Barnes, 2006: 41, character 50, Figure 8; Figure 8 herein).
51. Mandible cross section not dorsoventrally flattened [0]; or symphyseal portion of
the mandible flattened dorsoventrally so that so that in at least its middle one-half the