Lacerta gigantea, Young & Andrade, 2009

Young, Mark Thomas & Andrade, Marco Brandalise De, 2009, What is Geosaurus? Redescription of Geosaurus giganteus (Thalattosuchia: Metriorhynchidae) from the Upper Jurassic of Bayern, Germany, Zoological Journal of the Linnean Society 157 (3), pp. 551-585 : 559

GEOSAURUS GIGANTEUS ( VON SÖMMERRING, 1816) CUVIER, 1824 SENSU VON QUENSTEDT, 1852

1816 Lacerta gigantea sp. nov.; Von Sömmerring.

1824 Lacerta (Geosaurus) gigantea subgen. nov.; Cuvier.

1826 Halilimnosaurus crocodiloides gen. et sp. nov.; Ritgen.

1829 Mosasaurus Bavaricus epithet nov.; Holl.

1831 Geosaurus Sömmerringii epithet nov.; Von Meyer.

1842 Brachytaenius perennis gen. et sp. nov.; Von Meyer.

1852 Geosaurus giganteus just. emend.; Von Quenstedt.

1859 Geosaurus Sömmerringi just. emend.; Von Meyer.

1869 Mosasaurus giganteus comb. nov.; Cope.

Holotype: NHM R.1229: middle portion of cranium and mandible, badly deformed.

Type locality and horizon: Daiting, near Monheim, Bayern, Germany. Mörnsheim Formation, early Tithonian–uppermost hybonotum Tethys ammonite zone.

Referred specimens: NHM R.1230, four slabs of lithographic limestone: (1) lateral mid-portion of cranium consisting of lateral portion of the prefrontal, and frontal and postorbital portions of the beginning of the supratemporal arch; (2) anterior dorsals in ventral view with associated ribs; (3) mid-dorsals in ventral view with associated ribs; and (4) both sacrals in ventral view with gastralia, two pubis, incomplete femora proximal heads, isolated ribs, part of ischium, and illac blade (Daiting, Mörnsheim Formation). NHM 37016: tooth crown lacking apex, base, and root (Solnhofen, Solnhofen Formation). NHM 37020: skull and mandible embedded within lithographic limestone, only visible in left lateral view (Solnhofen, Solnhofen Formation) .

Emended diagnosis: Metriorhynchid thalattosuchian with strongly lateromedially compressed teeth, with a brevirostrine snout, keeled denticulate carinae; premaxillary, maxillary, and dentary teeth tri-faceted upon their labial surface; notch at the premaxilla– maxilla contact, which an enlarged dentary tooth fits into; dentary tooth opposite to premaxillary-maxillary suture enlarged; upper and lower jaw dentition arranged as opposing blades; cranial bones smooth, lacking conspicuous ornamentation; acute angle formed by the lateral and medial processes of the frontal; surangular poorly developed, terminating caudal to the anterior margin of the orbit; mandibular symphysis terminating prior to the antorbital fossa; robust and well-developed sclerotic ring encompassing the entire orbit.