Cricosaurus, WAGNER, 1858

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 : 851-852

CRICOSAURUS WAGNER, 1858

Neustosaurus Raspail, 1842 (nomen dubium) Enaliosuchus Koken, 1883

Crikosaurus Kotsakis & Nicosia, 1980 [sic] Type species: Cricosaurus elegans (Wagner, 1852) Wagner, 1858 .

Valid species: Cricosaurus araucanensis (Gasparini & Dellapé, 1976) Young & Andrade, 2009 ; C. elegans (Wagner, 1852) Wagner, 1858 ; Cricosaurus gracilis (Philips, 1871) Young & Andrade, 2009 ; Cricosaurus macrospondylus (Koken, 1883) Young & Andrade, 2009 ; C. saltillense (Buchy et al., 2006) Young & Andrade, 2009 ; Cricosaurus schroederi (Kuhn, 1936) Young & Andrade, 2009 ; Cricosaurus suevicus (Fraas, 1901) Young & Andrade, 2009 ; Cricosaurus vignaudi (Frey et al., 2002) Young & Andrade, 2009 .

Potentially valid species: The revaluation of Plesiosaurus (Polyptychodon) mexicanus Wieland, 1910 as a metriorhynchid, and not a sauropterygian, suggests that there is possibly another species of Cricosaurus in Mexico (see Buchy, 2008b). The dental and rostral morphology is consistent with Cricosaurus (procumbent, uncarinated, uncompressed crowns, with fine longitudinal ridges running from base to apex; tubular snout with the dentary and maxilla in parallel), and herein is provisionally referred to as? Cricosaurus mexicanus .

Etymology: ‘Ring lizard’. Cricos - is Ancient Greek for ‘ring’, referring to the large sclerotic rings preserved in the orbits of the holotype.

Geological range: Middle Oxfordian ( Cricosaurus sp. ; Gasparini & Iturralde-Vinent, 2001) to upper Valanginian ( C. macrospondylus holotype; Koken, 1883; Karl et al., 2006).

Geographical range: Cosmopolitan ( Argentina, Chile, Cuba, England, France, Germany, Mexico, Russia, and Switzerland).

Diagnosis: Metriorhynchid thalattosuchian with procumbent teeth, with little to no lateromedial compression; cranial bones smooth, and lacking conspicuous ornamentation; an acute angle is formed by the lateral and medial processes of the frontal; the dorsal margin of the supratemporal arcade is lower than the medial process of the frontal; the eyes are as large as the supratemporal fenestra; the surangular and angular are well-developed, extending rostrally beyond the orbits; the symphysial part of the mandible is low, only about 15-mm high; the lateral margin of the prefrontals is rounded; the external nares are bifurcated by the premaxillary septum and terminate at the end of the second maxillary alveoli; the humerus deltopectoral crest is absent; the calcaneum tuber is either absent or vestigial; the proximal end of metatarsal I is greatly enlarged.