Geosaurus (sensu Young & Andrade, 2009)

Young, Mark T., Brusatte, Stephen L., Ruta, Marcello & Andrade, Marco Brandalise De, 2010, The evolution of Metriorhynchoidea (mesoeucrocodylia, thalattosuchia): an integrated approach using geometric morphometrics, analysis of disparity, and biomechanics, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 158 (4), pp. 801-859 : 856

GEOSAURUS CUVIER, 1824

Halimnosaurus Ritgen, 1826

Brachytaenius von Meyer, 1842

Ltliminosaurus [sic] Romer, 1966 Type species: Geosaurus giganteus (von Sömmerring, 1816) Cuvier, 1824 sensu von Quenstedt, 1852 .

Valid species: Geosaurus carpenteri (Wilkinson et al., 2008) Young & Andrade, 2009 ; G. giganteus (von Sömmerring, 1816) Cuvier, 1824 sensu von Quenstedt, 1852 ; Geosaurus grandis (Wagner, 1858) von Zittel, 1887 –1890; Geosaurus lapparenti (Debelmas & Strannoloubsky, 1957) Young & Andrade, 2009 .

Etymology: ‘Earth lizard’. Ge - is the Ancient Greek for ‘earth’ (in the sense of ground), as the holotype was found within the limestones of Germany.

Geological range: Lower Oxfordian (cordatum ammonite zone; NHM 36336 and NHM 36339)– upper Valanginian (peregrinus ammonite zone; G. lapparenti ) .

Geographical range: European endemic ( England, France, Germany, Italy, and Switzerland).

Diagnosis: Metriorhynchid thalattosuchian with strongly lateromedially compressed teeth, and with a keeled denticulate carinae; the premaxillary, maxillary, and dentary teeth are tri-faceted upon their labial surface; there is a notch at the premaxilla– maxilla contact that an enlarged dentary tooth fits into; 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.