The Vallparadís composite section includes the paleontological sites of Cal Guardiola and Vallparadís Estació, respectively located in the western and eastern bank of the Torrent de Vallparadís (Terrassa, Catalonia, NE Spain). The Vallparadís section spans from before the Jaramillo subchron to the early Middle Pleistocene (ca. 1.2–0.6 Ma). It includes more than ten layers from which about 30,000 well-preserved large mammal remains have been recovered.
In this study, we describe the suid record from Vallparadís Section. This sample, although relatively small when compared with those of other large mammals from the same site (e.g., hippo or deer), includes a nearly complete skull, several teeth, and postcranial elements, and stands out as the richest European suid collection from the late Early Pleistocene. Suid remains have been discovered from both Cal Guardiola and Vallparadís Estació layers, whose age spans from the Jaramillo subchron (ca. 1.07–0.99 Ma; layer EVT12) to post-Jaramillo time (ca. 0.99–0.78 Ma; layers CGRD7 and EVT7).
Several cranial morphological features of the studied sample support an attribution to Sus strozzii Forsyth Major, 1881, although the Vallparadís Section suid falls in the lower dimensional range of Early Pleistocene S. strozzii. These morphological features include a low and very deep preorbital fossa, a narrow nuchal crest, a well-developed longitudinal swelling in the mid of the mandibular corpus, the presence of styles/stylids in the upper/lower premolars, and especially the “verrucosic” morphology of the lower canine (labial and lingual sides of the tooth with similar length, and longer than the distal side). The attribution to S. strozzii is also supported by phylogenetic data.
These results open new interesting questions on the chronological occurrence of Quaternary suids. Sus strozzii is relatively common in Europe during the middle and early late Villafranchian (ca. 2.5–1.8 Ma), while it almost completely disappears during the latest Villafranchian (ca. 1.8–1.2 Ma) (only few isolated undeterminable suid teeth are available from Sima del Elefante in this time span). During and slightly after the Epivillafranchian (ca. 1.2–0.9 Ma), S. strozzii reappears in Europe although with relatively small samples, at Vallparadís Section and several other sites, whose record is reviewed in this study. These sites include Untermassfeld (Germany; ca. 1.0 Ma), Le Vallonnet (France; ca. 1.2–1.1 Ma), Taman Peninsula (Russia; ca. 1.1–0.8 Ma), Arda River (Italy; ca. 0.99 Ma),
and probably Slivia (Italy; ca. 0.8 Ma).
Consequently, in contrast to what has been believed so far, we think that (1) S. strozzii survived in Europe (or returned there with a second dispersal event from Asia during the Epivillafranchian) at least until the end of the Early Pleistocene and (2) therefore the arrival of the wild boar Sus scrofa in our continent is not earlier than the Early-Middle Pleistocene boundary
