Department of Integrative Biology

Paleorhodococcus dominicanus n. gen., n sp. (Actinobacteria) is described from a faecal droplet of Triatoma dominicana (Hemiptera: Reduviidae: Triatominae) in Dominican amber. The fossil can be distinguished from the species of the closely related extant genus Rhodococcus Zopf 1891 by its spherical-ellipsoidal cocci forming substrate filaments with elementary branching, the clustering of coccoidal elements, the short filaments bearing reduced side branches and its occurrence in a faecal droplet of the extinct triatomine bug, P. dominicanus. This is the first fossil record of an Actinobacter, which shows that these organisms formed symbiotic associations with insects by the mid-Tertiary.