[1] The genus currently contains six species, all of which are known from the early Miocene Burdigalian[2] stage Dominican amber deposits on the island of Hispaniola.

[1] O. eickworti is known from the holotype only, a single 7.6 millimetres (0.30 in) long female currently in the private collection owned by Ettore Morone of Turin, Italy as number "684".

[4] The single 7.2 millimetres (0.28 in) long bee specimen is deposited in the American Museum of Natural History Department of Entomology as number "DR-14-839".

[5] The species, named in honor of Jerome G. Rozen, Jr. of the American Museum of Natural History, is distinguishable from other members of the genus by the lack of and acarinarium on the upper side of the metasoma.

[5] The first species to be described from more than one individual bee was O. marquettorum, which was described from both a holotype and a paratype, both females, preserved in a single amber specimen.

[6] Published in the May/June 2000 issue of the journal Apidologie, the amber containing the two bees is in the American Museum of Natural History as number "DR-14-1484".

[2] This name refers to the species' distinct rugulose gena which along with the pronotal angle, the partially and sculpturing of the face, mesosoma, and metasomal terga are unique.