Dental remains of 'Parachleuastochoerus' valentini (Suidae: Tetraconodontinae) from the early Late Miocene of Sant Quirze (Valles-Penedes Basin, NE Iberian Peninsula): taxonomic and phylogenetic implications

The distinctiveness and genus allocation of 'Parachleuastochoerus' valentini (Suidae: Tetraconodontinae), from the Miocene of Europe, has been controversial, being alternatively considered a junior synonym of Conohyus simorrensis. Recently described material from the Valles-Penedes Basin (NE Iberian Peninsula) supported its distinct species status but did not discount an alternative ascription to Conohyus, largely because the lower male canine remained unknown. Here we describe all the tetraconodontine dentognathic material from the earliest Late Miocene sites of Trinxera del Ferrocarril-Sant Quirze (similar to 11.6-11.2 Ma, MN7+8), as well as Can Feliu 2 and Poble Nou de Sant Quirze (<= 11.2 Ma, MN9), comprising 134 specimens. The former locality played an important role in the resurrection of 'Pa.' valentini but similar to 70% of the available material remained unpublished. Based on metrical and qualitative comparisons with published material of this species and similarly sized tetraconodontines from Europe, we attribute the whole studied sample to 'Pa.' valentini. Previous reports of Parachleuastochoerus huenermanni from the site are erroneous (owing to specimen mislabeling). Our results reinforce the distinctiveness of 'Pa.' valentini, while its lower male canine morphology (first described herein) does not support its transfer to Conohyus. However, a cladistic analysis favors closer phylogenetic relationships with Retroporcus matritensis (a potential junior synonym of C. simorrensis) and even Versoporcus steinheimensis than with Parachleuastochoerus crusafonti (the type species of the genus). Our results thus indicate that Parachleuastochoerus, as currently conceived, is polyphyletic, although pending an in-depth revision of other European tetraconodontines we refrain from providing a new combination for 'Pa.' valentini.