The university says Marina and Celina Suarez found the bones of a bird-like raptor in 2004 during a research expedition in Utah.
Now, the species will go by the name of Geminiraptor suarezarum.
The 29-year-old twins are from San Antonio. They were pursuing master's degrees at Temple University when they made the discovery.
Celina Suarez completed her doctorate in geology at the University of Kansas in spring 2010. Her sister completed her doctorate degree in fall 2009.
Marina Suarez is completing postdoctoral work at Johns Hopkins University's earth and planetary sciences department. Her sister begins as a postdoctoral researcher at Boise State University in Idaho this month.