Laurasian “opossum-like” marsupialiforms (Peradectidae and Herpetotheriidae), represented at Messel by partial skeletons, are extinct taxa mostly known from isolated tribosphenic molars. Their blurred evolutionary histories are marked by subtle and often homoplastic morphological character state transformations. However, disentangling such phylogenetic affinities is essential for a comprehensive understanding of metatherian evolution. Here, we introduce a novel matrix of selected dental characters, with taxon sampling focused on the crucial periods preceding and following the Cretaceous/Paleogene boundary, to unravel the phylogenetic positions of peradectids and herpetotheriids within Metatheria, and the intrafamilial relationships of peradectids. Parsimony and Bayesian analyses reveal that all the studied Cenozoic metatherians newly assemble into a clade, thereby confirming that metatherians were heavily impacted by the K–Pg mass extinction. Two enigmatic early Paleocene genera have crucial positions allowing us to identify the rapid Paleocene North American divergence of peradectids and herpetotheriids. For the first time, a monophyletic Peradectidae, with all (more than 20) the North American and European species allocated to this family, is recovered in a broad spatiotemporal and taxonomic context. Reconstructing the sequence of appearance of dental features within Peradectidae leads us to characterize each phase of their morphological evolution and refine their complex systematics. All known European peradectid species form a distinct clade, suggesting that peradectids likely dispersed only once from North America to Europe, just after the Paleocene-Eocene Thermal Maximum. In light of the new phylogenetic framework providing the synapomorphies of unequivocal peradectids, our revision of all specimens previously ascribed to Peradectidae from South America, Africa, and Asia shows that this family was most likely endemic to North America and Europe throughout its evolutionary history. Consequently, the paleobiogeographic history inferred for Laurasian metatherians turns out to be simpler than expected by past studies, and less puzzling than the biogeography of the Southern Hemisphere metatherians as understood based on fossil evidence. These results emphasize the pivotal role of compared dental anatomy in understanding the evolution and ultimately the paleobiogeography of metatherians, especially for taxa with apparently conservative morphology.
- A comprehensive evolutionary history of Peradectidae (Metatheria) revealed by a new phylogenetic framework based on dental morphology
- Killian Gernelle - Université de Montpellier, ISEM - Institut des Sciences de l'Evolution - MontpellierSandrine Ladevèze - Centre de recherche en paléontologie - ParisRodolphe Tabuce - Université de Montpellier, ISEM - Institut des Sciences de l'Evolution - Montpellier
- The World at the Time of Messel. Back to the Future? International Senckenberg Conference. 8th - 13th December 2025 Frankfurt am Main. Conference volume (Frankfurt am Main: Senckenberg Gesellschaft für Naturforschung, Germany, 08/12/2025–13/12/2025)
- French Ministry of Higher Education, Research, and Innovation
- 99239808109311
- ISEM - Institut des Sciences de l'Evolution - Montpellier
- English
- Conference poster
- hal-05597365