Suidae Transition at the Miocene-Pliocene Boundary: a Reassessment of the Taxonomy and Chronology of Propotamochoerus provincialis

Abstract

The Miocene-Pliocene (Turolian-Ruscinian) transition represents a fundamental interval in the evolution of Euro-Mediterranean paleocommunities. In fact, the paleoenvironmental changes connected with the end of the Messinian salinity crisis are reflected by a major renewal in mammal faunal assemblages. An important bioevent among terrestrial large mammals is the dispersal of the genus Sus, which replaced all other suid species during the Pliocene. Despite its possible paleoecological and biochronological relevance, correlations based on this bioevent are undermined by the supposed persistence of the late surviving late Miocene Propotamochoerus provincialis. However, a recent revision of the type material of this species revealed an admixture with remains of Sus strozzii, an early Pleistocene (Middle Villafranchian to Epivillafranchian) suid, questioning both the diagnosis and chronological range of P. provincialis. Here we review the late Miocene Suidae sample recovered from the Casino Basin (Tuscany, central Italy), whose taxonomic attribution has been controversial over the nearly 150 years since its discovery. Following a comparison with other Miocene, Pliocene, and Pleistocene Eurasian species, the Casino Suidae are assigned to P. provincialis and the species diagnosis is emended. Moreover, it is recognized that all the late Miocene (Turolian) European Propotamochoerus material belongs to P. provincialis and that there is no compelling evidence of the occurrence of this species beyond the Turolian-Ruscinian transition (MN13-MN14).

What Does the “Elephant-Equus” Event Mean Today? Reflections on Mammal Dispersal Events around the Pliocene-Pleistocene Boundary and the Flexible Ambiguity of Biochronology

“…For instance, some suids remains have been referred to as Listriodon von Meyer, 1846 [157], and cf. "Microstonyx" major (Kaup, 1833) [158][159][160], the latter species being more commonly placed in Hippopotamodon Lydekker, 1877 [161], in the recent literature [162]. For completeness, it is worth mentioning that another notable alleged earliest European occurrence based on the material from Vialette, that of Canis Linnaeus, 1758 [51], which played a significant role in the decline of the use of Azzaroli's "Wolf event" [28,29], has also been recently questioned by Böhme et al [90], who regarded it as Eucyon Tedford & Qiu, 1996 [163].…”

Earliest Vallesian suid remains from Creu de Conill 20 (Vallès-Penedès Basin, NE Iberian Peninsula)

“…Nevertheless, noted that P. hysudricus differs from P. palaeochoerus in the generally simpler (even if large) third lobe of the m3 and the size of particular tooth loci. Other species of Propotamochoerus recognized in Europe are P. provincialis and P. aegaeus from eastern Europe and Turkey (Geraads et al 2008;Pickford 2013;Lazaridis 2015;Iannucci et al 2021;Kostopoulos and Sylvestrou 2022;Lazaridis et al 2022), both recorded during the Turolian and whose distinction has been disputed (Iannucci et al 2021), whereas P. hyotherioides is recorded in the latest Miocene of China (Van der Made and Han 1994;Hou et al 2019).…”

Suidae (Mammalia, Artiodactyla) from the late Miocene hominoid locality of Alsótelekes (Hungary)

“…provincialis, and Pr. wui (Hünermann, 1968;Schmidt-Kittler, 1971;Pickford, 1988Pickford, , 2013Van der Made and Moyà-Solà, 1989;Van der Made and Han, 1994;Fortelius et al, 1996a;Van der Made et al, 1999;Geraads et al, 2008;Sein et al, 2009;Hou et al, 2019;Iannucci et al, 2021). Isolated teeth of these species are of similar morphology and partly overlap in size, and hence they are often difficult to identify.…”

“…(Van der Made, 1999;Geraads et al, 2008) and then to Pr. provincialis (Iannucci et al, 2021). Once excluded the putative late records, the chronological distribution of Pr.…”

“…palaeochoerus as well as the folivore listriodonts went extinct during the second half of the Vallesian (MN 10). After that, probably taking advantage of the concurrent environmental changes, Suinae became dominant and new species of Propotamochoerus and Hippopotamodon charac-terized Turolian (MN 11-MN 13; $8.9-5.3 Ma) assemblages of Europe (Fortelius et al, 1996a;Iannucci et al, 2021).…”