The Fossil Members of the Ant Tribe Leptomyrmecini (Hymenoptera: Formicidae)

In 1980 Baroni Urbani described Leptomyrmex neotropicus from 9 rather poorly preserved specimens clustered in a single piece of Dominican amber and hence presumed to be of Miocene age (the date estimated in Baroni Urbani and Saunders, 1982).The finding is of potential biogeographic importance because Leptomyrmex, and hence the very distinctive dolichoderine tribe Leptomyrmecini, is today limited to the Old World, in particular eastern Australia, New Caledonia, New Guinea, the Aru Islands, and the Moluccas.A second genus, Leptomyrmula, had previously been described from the Miocene amber of Sicily (Emery, 1891, 1912).It thus appears that an entire tribe was once almost worldwide but has since retreated not only from Europe but the entire Western Hemisphere.Wilson (1985a) doubted Baroni Urbani's tribal placement of the Dominican amber specimens.He found a worker in Dominican amber that superficially resembles Leptomyrmex, sharing the same distinctively elongated body form, mesothoracic constriction, peti- ole, tapered neck, and bulging eyes located toward the rear of the head, but actually belongs to the Camponotus branneri group.He suggested that Leptomyrmex neotropicus might be the same species.In the meantime, Schlee (1984) published a color photograph of another Dominican amber piece containing four presumed Leptomyrmex workers.This example is now preserved in the collection of