The oldest record of Lophoranina (Decapoda: Raninidae) from the late Cretaceous of Chiapas, southeastern Mexico

Abstract

The description of Lophoranina precocious new species from the Late Cretaceous (early Maastrichtian) Ocozocuautla Formation, Chiapas, Mexico, represents the first occurrence of Lophoranina in pre-Eocene strata. The discovery provides documentation that the evolutionary development of terraced lines in the genus trended from relatively few, undivided, symmetrical terraces to more numerous, divided, asymmetrical terraces, and that the overall carapace surface developed a lower relief and became more uniform through time. Terraced lines that appear to be nodose, in most cases, were probably spinose. The morphology of the dorsal carapace seems to support affinities of the Raninidae with the Homolidae.