The Cuban Crocodile, Crocodylus rhombifer, from late Quaternary fossil deposits on Grand Cayman
Caribbean Journal of Science
1993
Journal Article
29
3-4
153-164
Cyclura nubila
Fossil remains of crocodiles have been recovered from six sites on Grand Cayman, a small island in the northwestern Caribbean Sea about 250 km south of Cuba. The three most productive fossil faunas (Chisholm Cow Well, Crocodile Canal, and Furtherland Farms Cow Well) were deposited in aquatic depositional environments, based on the presence of dark organic sediments and the predominance of freshwater and estuarine vertebrates. Radiocarbon dates of 860 ± 50 yBP and 375 ± 60 yBP obtained on peat samples from the Crocodile Canal site confirm that crocodiles inhabited Grand Cayman until the late Holocene, although they are no longer found there. The Grand Cayman fossil sample contains four nearly complete skulls that closely resemble modern specimens of the Cuban crocodile, Crocodylus rhombifer Cuvier. The diagnostic cranial features they share include: comparatively short, broad, and deep rostrum; large orbits; strongly concave cranial roof and interorbital region; prominent ridges on dorsal margin of orbits and lateral edge of postorbital and squamosals, terminating in a rounded protuberance on posterolateral corner of squamosals; premaxillary/maxillary suture on palate transverse at level of first maxillary tooth; and 13 maxillary teeth. Most of the fossils in the extensive sample of C. rhombifer from Grand Cayman represent juvenile and subadult individuals. The name of the Cayman Islands is probably derived from the abundance of crocodiles prior to their local extinction during the last century.