Taxinomic revisions of Plio-Pleistocene suids from northern Africa: implications for biochronology and paleobiogeography.

Plio-Pleistocene suids from northern Africa are frequently discussed as evidence for biochronological correlations of hominid-bearing sites and dispersals of fauna from Africa to Eurasia. Here we use classic comparative anatomy and morphometrics of craniomandibular and dental remains, supplemented with investigations of internal structures using CT scan, to revise suid material from northern Africa. Main results are summarized here. 1) Three different lines of evidence (craniomandibular, petrosal, and dental morphology) strongly align the abundant material from Ahl al Oughlam, Morocco, with the genus Metridiochoerus rather than Kolpochoerus. 2) The type material of Omochoerus maroccanus, an upper fourth premolar and an upper third molar from unknown stratigraphic context in Morocco, also shares dental similarities with the suid from Ahl al Oughlam and therefore aligns with the genus Metridiochoerus. Other possible occurrences of O. maroccanus in northern Africa either represent K. limnetes (Mansourah, Algeria) or K. majus (Thomas Quarry, Morocco). 3) A single unworn upper third molar from Thomas Quarry, level L, was previously attributed to Kolpochoerus cf. maroccanus. Internal and external dental morphology and metrics are similar to that of specimens of K. majus from eastern African sites dated to ca. 1 Ma (Daka Member, Bouri Formation, Ethiopia; Buia, Eritrea), suggesting a paleobiogeographic connection between the two regions some time before 1 Ma. Other fossils from northern Africa could belong to this species (e.g., Erg Tihodaine, Algeria). 4) Abundant warthog (Phacochoerus) fossils from Allobroges (Algeria) reveal a combination of craniomandibular and dental characters that is unknown in other African sites, potentially representing a different, new species. This list of taxinomic revisions highlights the crucial contribution of taxinomy to document paleobiodiversity and investigate broader evolutive and paleoenvironmental research questions.