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

Abstract

Although the suid assemblages from the Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula) are reasonably well known, taxonomic studies devoted to them have lagged behind during the last decades. We describe the unpublished suid dentognathic remains from the earliest Vallesian (MN9) of Creu de Conill 20 (CCN20; 11.18 Ma), which represents the First Appearance Datum of hipparionin equids in western Europe. The sample includes 118 specimens, mostly isolated teeth, and a few maxillary and mandibular fragments. More than three-quarters of the specimens are assigned to the suine Propotamochoerus palaeochoerus, which is characteristic of MN9, albeit the described remains are slightly larger than average for the species. The rest of the sample belongs to a large tetraconodontine that is assigned to Parachleuastochoerus valentini, recorded elsewhere from MN7+8 to MN9, except for two specimens attributed to the small suid cf. Albanohyus sp. Our results support a synchronous dispersal of Hippotherium and P. palaeochoerus into Western Europe at ~11.2 Ma, suggesting that the latter is a suitable biochronological marker of the Vallesian. In turn, the remains of Pa. valentini refine our knowledge on the dental morphology of this species and strengthen the view that this species (unlike Conohyus doati and Conohyus melendezi) is not a junior synonym of Conohyus simorrensis. The lack of Listriodon splendens and Versoporcus sp. from CCN20, together with the scarcity of Albanohyus, contrasts with their abundance in the roughly coeval site of Castell de Barberà, hinting at local paleoenvironmental differences.