Paleosuchus

Paleosuchus is a South American genus of reptiles in the subfamily Caimaninae of the family Alligatoridae. They are the smallest members of the order Crocodilia in the Americas.^[2]

Paleosuchus Temporal range: Late Pleistocene - Recent, 0.1–0 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Paleosuchus palpebrosus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauromorpha
Clade:	Archosauriformes
Order:	Crocodilia
Family:	Alligatoridae
Subfamily:	Caimaninae
Genus:	Paleosuchus Gray, 1862
Species
Paleosuchus palpebrosus Paleosuchus trigonatus

Classification

The genus name Paleosuchus is derived from the Greek palaios meaning "ancient" and soukhos meaning "crocodile god Sobek". This refers to the belief that this crocodile comes from an ancient lineage that diverged from other species of caimans some 30 million years ago.^[3]

At present, Paleosuchus contains only two members: the smooth-fronted or Schneider's dwarf caiman (Paleosuchus trigonatus) and Cuvier's dwarf caiman (Paleosuchus palpebrosus), both from South America.

Paleosuchus is distinguished from other caimans in the subfamily Caimaninae by the absence of an interorbital ridge and the presence of four teeth in the premaxilla region of the jaw, where other species of caimans have five.^[3] The relationships of extant (living) caimans can be shown in the cladogram below, based on molecular DNA-based phylogenetic studies:^[4]

Alligatoridae	Caimaninae Paleosuchus palpebrosus Cuvier's dwarf caiman Paleosuchus trigonatus Schneider's dwarf caiman Jacarea Caiman crocodilus Spectacled caiman Caiman yacare Yacare caiman Caiman latirostris Broad-snouted caiman Melanosuchus niger Black caiman Alligatorinae Alligator sinensis Chinese alligator Alligator mississippiensis American alligator

Species

The genus contains the following two extant species^[5] and a yet unnamed fossil species.^[6]

Image	Scientific name	Common name	Distribution
	P. palpebrosus	Cuvier's dwarf caiman	Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad, and Venezuela
	P. trigonatus	Smooth-fronted caiman	Amazon and Orinoco Basins

References

1. Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
2. Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey (2014). The Animal Diversity Web (online). Accessed at http://animaldiversity.org.
3. Britton, Adam (2009-01-01). "Paleosuchus palpebrosus (Cuvier, 1807)". Crocodilian species list. Retrieved 2013-10-28.
4. Bittencourt, Pedro Senna; Campos, Zilca; Muniz, Fabio de Lima; Marioni, Boris; Souza, Bruno Campos; Da Silveira, Ronis; de Thoisy, Benoit; Hrbek, Tomas; Farias, Izeni Pires (22 March 2019). "Evidence of cryptic lineages within a small South American crocodilian: the Schneider's dwarf caiman Paleosuchus trigonatus (Alligatoridae: Caimaninae)". PeerJ. 7: e6580. doi:10.7717/peerj.6580. PMC 6433001. PMID 30931177.
5. Alderton, D. (1991). Crocodiles and Alligators of the World. New York: Facts on File Publications.
6. Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Wesselingh, Frank P.; Antoine, Pierre-Olivier (2015-04-07). "A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands". Proceedings of the Royal Society B: Biological Sciences. 282 (1804): 20142490. doi:10.1098/rspb.2014.2490. PMC 4375856. PMID 25716785.

External links

Media related to Paleosuchus at Wikimedia Commons