New fossil belonged to the 31st known species of a group of reptiles that lived in South America between 23 million and 5 million years ago Jonas Pereira De Souza-Filho & Edson Guilherme “We suspect that the horns of the Acresuchus were a feature that distinguished males from females and were used during mating rituals,” says paleontologist Giovanne Cidade, a PhD student being supervised by Hsiou and coauthor of the article. Gerry Zambonini / Wikimedia Commons The cuban crocodile which moves its head so as to show the protrusions of its skull during mating ritualsGerry Zambonini / Wikimedia Commons An analysis of 187 anatomical features of 93 live and extinct crocodilian species indicates that Acresuchus is the closest relative of the extinct Purussaurus was a transitionary species between the smaller and larger crocodilians Diverse species and forms The official description of Acresuchus brings to 31 the number of species of these predators that lived in South America in the Miocene period between 23 million and 5.3 million years ago Only one—the broad-snouted caiman (Caiman latirostris)—has survived to this day Five other more recent species of these reptiles also live in Brazil today “Fossil records show that crocodilians were at the height of their diversity during the Miocene geological period,” says Cidade In a review article published in the Journal of South American Earth Sciences in December 2018 before the Acresuchus was officially described Cidade identified 30 crocodilian species that lived in South America in the Miocene It was a super-wetland roughly the size of Europe In a review article published in the journal Earth-Science Reviews in 2010 Cozzuol and Argentine geologist Edgardo Latrubesse listed 224 genera of land and water animals—not including fish—that lived in South America at the end of the Miocene Two of the most diverse groups were the armadillos and sloths Hsiou and her team have described three new species of Miocene rodents since 2012 such a large variety of crocodilians would only be possible with a combination of the right environmental conditions and high diversity among other animals “To put it simply,” says Cozzuol “there was plenty of food available at the time © Revista Pesquisa FAPESP - All rights reserved.