The protocone and the
metaconule are oppressed to form a contiguous proto-metaconule complex.
M1 subtriangular, with well-developed
metaconule united to the protocone, lingual part with a tendency to reduction.
The
metaconule is present posterior to the protocone.
1 (basalmost artiodactyls [paraphyletic]: diacodexid, primitive [unassigned, some dichobunine] dichobunid dichobunoids): Ml-3 (Ms) bunodont, triangular;
metaconule unenlarged; no hypocone (Old World [OW] origin).
(SDSM 82103)--Wang's (5) diagnosis for the subfamily is based on cranial characters and dental characters of P4, M1, and m1 which cannot be used to determine the identification of the tooth and "the subfamily is mainly defined by its lack of synapomorphics for the other two subfamilies." The lack of the paraconule and
metaconule suggest a primitive morphology and support the assignment to the Hesperocyoninae.
Bailit 1980 The
metaconule: a morphological and familial analysis of a molar cusp in humans.
The
metaconule is pyramidal in shape with a moderately developed preme tacrista that is mesiolingually directed to join the slight lingual cingulum between protocone and
metaconule.
There is no clear cut demarcation between the
metaconule and the protocone.
The metacone is partially broken, and connected to the
metaconule by a narrow crest.
The tooth can be described as follows: ectoloph is typically W-shaped; hypocone is absent but a postprotocrista extends posteriad from the
metaconule as a curved sloping ridge with a small talon formed by its base.