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Boisserie JR, Souron A, Mackaye HT, Likius A, Vignaud P, Brunet M.
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PLoS One. 2014 Aug 27;9(8):e103221. doi: 10.1371/journal.pone.0103221. 2014.
Abstract
During the latest Miocene and the early Pliocene, tetraconodontine suids were the
most predominant large omnivorous mammals in Africa. Yet, new species were often
identified on the grounds of limited evidence, a situation impacting their value for
biochronological correlations as well as for environmental and biogeographical
reconstructions. The description of the most abundant known collection of
craniodental remains attributed to the tetraconodontine Nyanzachoerus helps to
improve this situation. These specimens were collected in the upper Miocene deposits
at Toros-Ménalla, northern Chad, central Africa, by the Mission Paléoanthropologique
Franco-Tchadienne. We compared them with Nyanzachoerus from eastern and southern
Africa, using extant species as a reference for patterns of morphological variation.
Thanks to a large sample of observations, our work focused as much on
craniomandibular morphology as on dental morphology and metrics (improved by an
index scoring for the complexity of distal third molars and a detailed investigation
of premolar-molar ratios). We recognized two taxa at Toros-Ménalla: Nyanzachoerus
khinzir nov. sp. and Ny. cf. australis. We also revised the taxonomic status for
other species, including: the restriction of Ny. syrticus to its holotype specimen
from Sahabi (Libya), the resurrection of the nomen Ny. tulotos, and the synonymy of
Ny. kuseralensis with Ny. waylandi. At Toros-Ménalla, Ny. khinzir was the only suid
coexisting with the anthracotheriid Libycosaurus and the hominid Sahelanthropus,
whereas Ny. cf. australis was associated with a different, probably younger faunal
context. Nyanzachoerus. khinzir, which probably had a diversified diet, supports a
latest Miocene biogeographical distinction between central Africa and eastern
Africa.
Keywords: .
Link/DOI: 10.1371/journal.pone.0103221