Culebrasuchus was first described and named by Alexander K. Hastings, Jonathan I. Bloch, Carlos A. Jaramillo, Aldo F. Rincona and Bruce J. Macfadden in
Caimaninae, meaning that it represents the earliest radiation of caimans in the Americas. The ancestor of Culebrasuchus likely lived farther north, perhaps in what is now southern Mexico, because before the Miocene most of Panama was underwater. The movement of Culebrasuchus into the Panama Canal Zone was an early part of the Great American Interchange in which animals dispersed between North and South America across the newly formed Isthmus of Panama (although during the Early Miocene it had not yet formed, with 20 km of ocean still separating the continents). However, Culebrasuchus was not the earliest caimanine; Orthogenysuchus and Tsoabichi are known from the Eocene of North America and Eocaiman is known from the Eocene of South America, indicating that caimanines were dispersing between the continents across large expanses of ocean long before the isthmus formed.[1]
Description
Like many living caimans, Culebrasuchus was small in size. Other caimans that lived during the same time in South America (including those in the genera
plesiomorphic ("primitive") for alligatorids. Culebrasuchus also has a straighter lower jaw than most other alligatorids, it lacks the ridges on the frontal bone between the eye sockets that are common among crocodylians, and the fourth tooth of the maxilla (rather than third, as in almost all other alligatorids) is the largest in the upper jaw.[1]
Classification
The 2013 study describing and naming Culebrasuchus placed it as the most
Caimanine,[1] and was confirmed by later studies.[2][3]
The below cladogram is from the initial 2013 study:[1]
Alternatively, a 2018 study by Bona et al. noted that Culebrasuchus was enigmatic and difficult to interpret, and instead proposed it to be a member of
Chinese Alligator, as shown in the cladogram below:[4]
