Portugalosuchus Explained

Portugalosuchus (meaning "crocodile from Portugal") is an extinct genus of eusuchian crocodyliform that was possibly a basal crocodylian – if so then it would be the oldest known crocodylian to date. The type species is P. azenhae, described in 2018,^[1] and it is known from the Late Cretaceous (Cenomanian)-aged Tentugal Formation in Portugal.^[2] A 2021 morphological study recovered Portugalosuchus within Crocodylia as a member of Gavialidae closely related to similar "thoracosaurs" (e.g. Thoracosaurus), while also noting that it might also possibly be outside of Crocodylia completely. A 2022 tip dating analysis incorporating both morphological and DNA data placed Portugalosuchus outside of Crocodylia, as the sister taxon of the family Allodaposuchidae. A cladogram simplified after that analysis is shown below:^[3]

The morphology-based phylogenetic analyses based on the new neuroanatomical data obtained from its skull using micro-CT scans suggested that this taxon is a crown group crocodilian and a member of the 'thoracosaurs', recovered as a sister taxon of Thoracosaurus within Gavialoidea,^[4] though it is uncertain whether 'thoracosaurs' were true gavialoids.^[5]

Notes and References

1. Octávio Mateus . Eduardo Puértolas-Pascual . Pedro M. Callapez . 2018 . A new eusuchian crocodylomorph from the Cenomanian (Late Cretaceous) of Portugal reveals novel implications on the origin of Crocodylia . Zoological Journal of the Linnean Society . 186 . 2 . 501–528 . 10.1093/zoolinnean/zly064 .
2. Web site: Portugalosuchus. Fossilworks. 17 December 2021.
3. Darlim . G. . Lee . M. S. Y. . Walter . J. . Rabi . M. . The impact of molecular data on the phylogenetic position of the putative oldest crown crocodilian and the age of the clade . Biology Letters . 2022 . 18 . 2 . 20210603 . 10.1098/rsbl.2021.0603. 35135314 . 8825999 .
4. Puértolas‐Pascual . Eduardo . Kuzmin . Ivan T. . Serrano‐Martínez . Alejandro . Mateus . Octávio . 2023-02-02 . Neuroanatomy of the crocodylomorph Portugalosuchus azenhae from the late cretaceous of Portugal . Journal of Anatomy . en . joa.13836 . 10.1111/joa.13836 . 0021-8782. free .
5. Hekkala . E. . Gatesy . J. . Narechania . A. . Meredith . R. . Russello . M. . Aardema . M. L. . Jensen . E. . Montanari . S. . Brochu . C. . Norell . M. . Amato . G. . 2021-04-27 . Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus . Communications Biology . en . 4 . 1 . 505 . 10.1038/s42003-021-02017-0 . 33907305 . 8079395 . 2399-3642 . free.