New ant species Schismiscapus exstinctum gen. et sp. nov. (Formicidae: Dolichoderinae) from Miocene Mexican amber

A new species of ant (Formicidae: Dolichoderinae) in Miocene Mexican amber is diagnosed and described. Schismiscapus exstinctum gen. et sp. nov. is recognised by having the base of scape flattened and notched; mesosoma long, narrow, and sinuous; hypostomal bridge forming a U-shaped notch without any denticule; anteromedial mesosternum convex; compound eyes positioned anteriorly on head; long post peduncle that joints with the gaster and a long spur on the hind tibiae. A phylogenetic analysis was performed to identify the position of S. exstinctum among dolichoderine ant genera. A close relationship with the genus Leptomyrmex Mayr, 1862 was revealed with both ant genera sharing a hypostomal bridge forming a U-shaped notch without any denticule. Thus, the fossil record of S. exstinctum in Miocene tropics of southern Mexico provides new insights into the evolutionary history of the Leptomyrmecini clade that has a probable Neotropical origin.