THE EVOLUTIONARY HISTORY AND PHYLOGENETIC RELATIONSHIPS OF THE SUPERFAMILY PLATANISTOIDEA - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 474

XXXI, Figure 4; and Figure 11A herein), and was described by Barnes (2006:41,
character 57).
58. Relationship of falciform process of squamosal bone to petrosal: anterior process
of petrosal has little contact with the falciform process [0]; or falciform process of
squamosal bone is enlarged and extends ventrally to have a wide contact with the
dorsal side of the anterior process of the petrosal [1]. The falciform process descends
from the ventral surface of the squamosal (Rommel, 1990: Figure 3; see Barnes,
2006:41, character 58). The plesiomorphic character state is present in many species
of the superfamily Delphinoidea, for example in the phocoenid Neophocaena
phocaenoides (Fraser & Purves, 1960: pl. 28). The derived character state is present
in Platanista gangetica (Fraser & Purves, 1960:pl. 17; and Figure 11C herein).
59. Supraorbital process of the frontal bone not fenestrated by extensions of the
pterygoid sinus [0]; or fenestration exists to some extent, spreading from the ventral
surface of the supraorbital process of the frontal via the area of the infraorbital
foramen system [1]. This occurs because of expansion of a lobe of the pterygoid air
sinus from the postorbital area dorsally into the ventral surface of the supraorbital
process of the frontal. In the derived character state, which exists in Platanista
gangetica, multiple branches of the pterygoid sinus extend dorsally toward the
infraorbital foramina and spread via the anterior maxillary foramina onto the dorsal
surface of the supraorbital process and into the medial side of the maxillary crest (see
Van Beneden & Gervais, 1868-1880:pl. XXX, Figures 19a, 19b; Kellogg, 1924: pl.
6; Fraser & Purves, 1960:91, Figure 17a, pls. 17-18; and Figure 11 herein).
(Character described by Barnes, 2006:41, character 59.)
60. Size of the orbit of normal proportions [0]; or eye much atrophied [1]. Defined by
Barnes (2006:41, character 60), the derived character state is present in Platanista
gangetica (see illustrations in Van Beneden & Gervais, 1868-1880: pl. XXXI,
Figures 2, 9; Kellogg, 1924: pl. 5; and Fraser & Purves, 1960:pls. 17-18; and Figure
11 herein). (Character defined by Barnes, 2006:41, character 60.)
61. Zygomatic process of the jugal narrow, thin, and rod-like in shape, as is the
condition in most odontocetes [0]; or zygomatic process of jugal secondarily
thickened and shortened anteroposteriorly [1]. This modification, defined by Barnes
(2006:41, character 61) is correlated with reduction of the size of the orbit, and the
derived character state is present in Platanista gangetica (see illustration of this
species by Van Beneden & Gervais, 1868-1880:pl. XXXI, figs. 2, 6, 9; and Fraser &
Purves, 1960:pl. 18, and Figures 11B and 11C herein).
62. Secondary heterodonty: crowns of teeth are similar in shape throughout the tooth
row, and are simple and conical [0]; or crowns of the posterior teeth are short and
widened transversely, in contrast to the crowns of the anterior teeth, which are
greatly elongated apically [1]. Defined by Barnes (2006:41-42, character 62), the
derived character state is present in Platanista gangetica (see Van Beneden &
Gervais, 1868-1880: pl. XXX, Figure 1; and pl. XXXI, Figures 1, 2, 2b, 9; and
Figures 10D and 11 herein).
63. Lambdoidal crest on the lateral side of the braincase present along the squamosal-
exoccipital suture on the surface of the lateral side of the braincase, dorsal to the
zygomatic process of the squamosal, the lambdoidal crest is elevated and discernible
[0]; or the lambdoidal crest in this area is reduced in size and is barely protruding