THE EVOLUTIONARY HISTORY AND PHYLOGENETIC RELATIONSHIPS OF THE SUPERFAMILY PLATANISTOIDEA - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 462

rims are round rather than being transversely flattened. Its presence in a marine deposit
indicates that Platanistinae were probably previously more widely distributed in oceans.
Figure 11. Cranium of the only living member of the superfamily Platanistoidea, a highly derived
member of the family Platanistidae, subfamily Platanistinae, Platanista gangetica (Roxburgh, 1801), an
adult female individual, CAS 16340, from Sind, Pakistan; A, dorsal view; B, left lateral view; C,
ventral view; scale bar equals 10 cm. The rostral curvature is not natural, and is the result of unequal
drying of the bone. Platanista is the type genus of the subfamily Platanistinae, the family Platanistidae,
and the superfamily Platanistoidea.
Platanista Wagler, 1830, is the only named genus that is now included in the subfamily
Platanistinae. Its recent species include the freshwater susus of south Asia. Usually one
species is recognized, Platanista gangetica (Roxburgh, 1801), and the subspecies name,
Platanista gangetica gangetica (Roxburgh, 1801), is applied to the Ganges River Dolphin of
the rivers of India, Bangladesh, Nepal, and the name Platanista gangetica minor Owen, 1853,
is given to the Indus Dolphin of Pakistan. These are among the most highly derived
odontocetes ever to have lived. Among their derived characters are: small size, enlarged and
anteriorly extended zygomatic process of the squamosal, atrophied eye, extreme left-skew
asymmetry of the cranial vertex, reduced nasal bones, greatly enlarged supraorbital crests
(formed by maxillary bones and pneumaticized by extensions from the middle ear air sinus
system), extremely narrow supraoccipital-nuchal crest region, reduced lambdoidal crests,
secondarily inflated zygomatic process of the jugal, transversely flattened rostrum and