New ant species S<i>chismiscapus exstinctum</i> 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. <i>Schismiscapus exstinctum</i> 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 <i>S. exstinctum</i> among dolichoderine ant genera. A close relationship with the genus <i>Leptomyrmex</i> 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 <i>S. exstinctum</i> in Miocene tropics of southern Mexico provides new insights into the evolutionary history of the Leptomyrmecini clade that has a probable Neotropical origin.