Kansajsuchus, EFIMOV, 1975

KANSAJSUCHUS EFIMOV, 1975

Type species: Kansajsuchus extensus Efimov, 1975 .

Synonymy: Turanosuchus Efimov, 1988 . Revised distribution: Late Cretaceous (Santonian– Campanian) of Kazakhstan and Tadzhikistan.

Revised diagnosis: Member of Paralligatoridae characterized by the following combination of characters (autapomorphies in the context of paralligatorids marked with an asterisk): premaxillary notch for the reception of the enlarged fourth dentary tooth (*); posterodorsal process of the premaxilla anteroposteriorly elongated (twice as long as the external narial fenestra) and lateromedially constricted (the process width at the level just posterior to the premaxillary tooth row is half the narial width); enlarged neurovascular foramen on the ventral surface of the premaxilla (ventral subnarial foramen); ornamentation absent on the anterior and lateral (alveolar) margins of the premaxilla; nasals separated from the posterior narial border dorsally by continuous contact between premaxillae posterior to the narial opening; fourth and fifth maxillary alveoli are the largest in the anterior part of the maxillary tooth row; ornamentation absent on the alveolar margins of the maxilla and the dentary; lacrimal longer than the prefrontal; sagittal frontal and transverse interorbital crests present on the interorbital region; dorsal groove (sulcus) present on the transverse interorbital crest; prefrontal forms most of the medial orbital margin with the frontal making up only a small posteromedial corner of the orbit (in adults) (*); frontals participating in the anterior border of the supratemporal fenestrae; longitudinal ridge on the lateral surface of the jugal; anterior process of the jugal dorsoventrally deep and mediolaterally flattened; enlarged subcircular supratemporal fenestrae (the maximum mediolateral width of the supratemporal fenestra is twice as large as the postorbital-squamosal bar width at the same level) (*); lateral lamina of the anterior squamosal process covering most of the lateral surface of the postorbital; dorsally flared lobule of the posterolateral squamosal process present; pronounced and elongated crests (crest A, crest A’, crest B) on the ventral surface of the quadrate; cranioquadrate passage laterally open; quadrate not participating in the formation of the cranioquadrate passage; elongated dentary symphysis, extending posteriorly up to the level of the seventh or eighth dentary alveolus in dorsal view (*); amphicoelous cervical and dorsal vertebrae; dorsal paravertebral osteoderms arranged in more than two longitudinal rows; dorsal keels on the paravertebral osteoderms high and restricted to the posterior margins of the plates; ventral polygonal and ovate osteoderms present.

Remarks on the diagnosis: The structure of the mandibular symphysis of the type species K. extensus from the type locality is as yet unknown. The available material from the Kansai locality indicates pronounced elongation of the rostrum of K. extensus (suggested by the presence of elongated and constricted posterodorsal processes of the premaxillae). This feature corresponds to the presence of an elongated mandibular symphysis, which is known for closely related forms from the Dzharakuduk and the Shakh Shakh localities.