Caimans are alligatoridcrocodylians within Caimaninae. The group is one of two primary lineages within Alligatoridae, the other being alligators. Caimans inhabit Central and South America. They are relatively small crocodylians, with most species reaching lengths of only a few metres, with the smallest being the Cuvier's dwarf caiman (Paleosuchus palpebrosus), which grows to 1 metre (3 feet) long and the largest being the black caiman (Melanosuchus niger), which can grow to 4 metres (13 ft) or more. Several extinct forms are known, including Purussaurus, a giant Miocene genus that grew to 12 metres (39 ft) and the equally large Mourasuchus, which had a wide duck-like snout.
^Brochu, C. A. (1999). "Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea". Society of Vertebrate Paleontology Memoir6: 9–100. doi:10.2307/3889340. JSTOR3889340.
^Brochu, C. A. (2011). "Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines". Zoological Journal of the Linnean Society163: S228–S256. doi:10.1111/j.1096-3642.2011.00716.x.edit
^Hastings, A. K.; Bloch, J. I.; Jaramillo, C. A.; Rincon, A. F.; MacFadden, B. J. (2013). "Systematics and biogeography of crocodylians from the Miocene of Panama". Journal of Vertebrate Paleontology33 (2): 239. doi:10.1080/02724634.2012.713814.edit