Pliopithecus is a genus of early primates comparable in body and dental size to that of the lesser apes.  Represented by four species, P. antiquus; P. piveteaui; P. platyodon; P. zhanxiangi, Pliopithecus is believed to be an ancestor of modern gibbons and siamangs (Fuentes).  Tall and narrow incisors, long and narrow lower molars, and broad, short upper post-canine teeth are a suite of primitive dental characteristics shared by the genus (Hartwig).

Pliopithecus piveteaui

Pliopithecus piveteaui
• Hurzeler, 1954
• Right mandibular fragment with M2 – M3 and alveoli for the roots of P4 and M1
• 17 – 16 MYA
• Loire Valley of France
A suite of dental characteristics displayed by the type specimen are all that distinguishes P. piveteaui from the other members of the genus. This mandibular fragment exhibits a distinct molar morphotype containing a very small and tapered M3 when compared to the distally narrowing M2 (Hartwig). The teeth are very small, but in the range of P. antiquus. Two upper teeth are known from the species, a P4 and M3. When the P4 is compared to an isolated P4 from Poland of either P. antiquus or P. platyodon, it is unconfirmed as to which species the isolated P4 belongs to, that of P. piveteaui is much smaller and broader (Hartwig).

Pliopithecus zhanxiangi

Pliopithecus zhanxiangi
• Harrison, et al., 1991
• BPV-1021, Female Cranium
• 16 MYA
• China
P. zhanxiangi is the largest member of the genus. According to Hartwig, “the lower molars increase drastically from M1 – M3 and the mandible is very robust. The upper canines are very thick and the post-canines are extremely broad. P. zhanxiangi had a short face, with a narrow and oval shaped nasal aperture, and broad orbits.”

Pliopithecus antiquus

Pliopithecus antiquus
• Gervais, 1849
• Mandible
• 15 MYA
• Sanson and Lo Grive, France
Only a small number of dental characteristics separate this species from the remainder of the genus: M2 displays a buccal cingulum, P4 has a small buccal surface, and the lower molars from M1 – M3 increase in size at a lower ratio than the others (Hartwig). Dental size of P. antiquus is among the smallest of the genus.

Pliopithecus platyodon

Pliopithecus platyodon
• Biederman, 1863
• Female maxilla
• 15 MYA
• Gorrach, Austria
This species differs from P. antiquus by means of greater dental size. The P3 is broader and the lower molars are longer and more rectangular with a greater increase in size ratio from M1 – M3 in P. platyodon (Hartwig). Some researchers believe that samples of both P. antiquus and P. platyodon are of the same species.