modularis" was the first known pterosaur to display features of both long-tailed ('rhamphorhynchoid') and short-tailed (pterodactyloid) pterosaurs, and was described as a transitional fossil between the two groups.Two additional species, "D. linglongtaensis" and "D. robustodens", were described from the same fossil beds in December 2010 and June 2011, respectively.