Gobicyon is an extinct genus of large-sized carnivoran mammals, belonging to the Amphicyonidae ("bear dogs"), that was discovered in China, Mongolia, and Serbia, and lived during the Middle Miocene epoch.
Despite only being known from rather fragmentary remains, recent discoveries showcase that it was an aberrant member of the subfamily Haplocyoninae, with adaptions towards bone-crushing similar to those of a hyaena.
[1] Gobicyon was described by Edwin Harris Colbert in 1939, on the basis of the anterior part of a mandible (AMNH FM2659) discovered in the Inner Mongolian Tunggur Formation, who considered it to be a relative of borophagine canids such as Aelurodon and Tomarctus.
[5] It should however be noted, that Gobicyon is only known from cranial and dental remains, which may lead to an overestimation of their mass, as some amphicyonids possess disproportionately large heads in comparison to their body size.
[6] The characteristic traits of Gobicyon are a short snout, deep mandibular ramus, an extremely broad and robust symphysis, giving it a hyaena-like appearance, and large premolars.
While the Zx/Zy values obtained for G. macrognathus are smaller than those of the temnocyonines, they still showcase their ability to resist the torsional stresses caused by struggling prey during the canine bite, as in large felids.
Due to this, some foot bones from the Halamagai Formation have been tentatively assigned to Gobicyon, which support the presence of cursorial adaptions in this genus.
[9] The protocone of its p4 is rather small, and the posterior molars are greatly reduced, whereas the premolars are robust and distinct posterolingual convexities are developed on P2 and P3.
G. serbiae is very similar to G. macrognathus, and differs from that species by the lack of anterior accessory cusps on p3 and p4, and by the lower margin of the enamel on its p4 and m1, which are nearly straight.
[1][7] The Halamagai Formation, where Gobicyon zhegalloi was discovered, preserves a diverse assemblage of amphicyonids, which also includes the large Amphicyon ulungurensis and several species of the genus Cynelos.
[13] Several smaller taxons known from the formation are also associated with arid and open habitats, most notably the ground squirrel Atlantoxerus[14] and the ochotonid Alloptox.
[16] These include Amphicyon and Cynelos,[7] bats, browsing proboscideans,[16] the beaver Steneofiber,[17] the cervid Stephanocemas, the moschid Micromeryx[18] and, most notably, the primate Pliopithecus.
[18][19] Other genera found at the site include the mustelid Tungurictis,[20] the small hyaenid Protictitherium, a nimravid, the browsing horse Anchitherium, the anthracothere Elomeryx[21] and the lagomerycid Stephanocemas.
All this indicated that the Tunggur Formation was deposited in a mixed environment of forests and open grasslands, with shallow rivers meandering through the landscape.
Other large predators of this locality include the sabertoothed-cat Metailurus and the barbourofelid Albanosmilus,[23] the possibly hyaenid Percrocuta and the wolf-sized Amphicyon tairumensis.
The herbivore assemblage includes a large variety of deer, the suids Listriodon and Kubanochoerus, the proboscidean Platybelodon, the bovid Turoceros, the equid Anchitherium, two species of rhinoceros and Chalicotherium.