摘要: The aardwolf Proteles cristatus is the only known hyaenid, living or extinct, to exhibit
an extremely reduced dentition related to its termite-specializing diet. The fossil record of extant
aardwolves extends to 2 to 4 million years ago, but records that inform its evolutionary origins
are essentially nonexistent. Such circumstance renders it difficult to place this unusual hyena in
the broader evolutionary context of small-bodied hyaenid species in Eurasian Neogene deposits.
Here we describe a new genus and species of a small-bodied hyaenid, Gansuyaena megalotis,
representing the closest morphological link to aardwolves to date. This new fossil hyena is based
on a skull with associated mandible, a rostrum preserving several teeth, and several referred
specimens. The new specimens were discovered in Neogene deposits in Linxia Basin, Gansu
Province, China. Phylogenetic analysis indicates that among early hyaenids, G. megalotis is most
closely related, but unlikely ancestral, to the living aardwolf. Also recognized in this new species
are the fossils previously referred to “Protictitherium” aff. P. gaillardi from Pasalar, Turkey.
Additionally, “Plioviverrops” guerini from Los Mansuetos, Spain is interpreted to represent a
second Gansuyaena species. In addition to the living aardwolf, Proteles cristatus, our analyses
suggest that the proteline lineage includes the extinct genera Gansuyaena, Mesoviverrops, and
Plioviverrops. Although the precise timing and geographic location of evolutionary divergence
between the aardwolf and Gansuyaena remain elusive, critical new morphological information
provided by Gansuyaena specimens reinforce findings from recent genomic analyses that the
aardwolf lineage has an ancient origin from small-bodied stem hyaenids prior to the appearance of
large and robust bone-cracking hyaenines.