A phylogenetic reconstruction of North American goniopholidid crocodyliforms

Goniopholidids are distant relatives of crocodiles and alligators from the Jurassic and Cretaceous (201- 66 mya) of North America and Europe. They are the first in this lineage with a body plan and, presumably, ecological role superficially resembling those of modern crocodylians. The flat, triangular skull and conical teeth typical of goniopholidids resemble those of most living crocodylians and are thought to typify the configuration of a generalized semiaquatic ambush predator with a broad prey base. This generalized morphology has caused them to receive little scientific attention historically. Unfortunately, this caused Goniopholididae to be treated as a wastebasket taxon, with any crocodylian relative during the age of the dinosaurs with generalized morphology liable to be referred to the group. Although European goniopholidid systematics have drawn substantial attention in the past two decades, considerably less effort has been directed toward the North American record of the group. This project revises the species-level taxonomy of North American goniopholidids, including a review of existing species and the description of new species. Also, phylogenetic analyses were conducted to help resolve the evolutionary relationships of goniopholidids and their closest relatives. The results of this study reveal novel evolutionary relationships that challenge long-held assumptions about the status and distribution of Goniopholididae, which had a more restrictive Jurassic and expansive Cretaceous distribution in North America than previously believed. Moreover, these results highlight the presence of a faunal exchange across North America and Europe within the group during the late Jurassic and early Cretaceous.