D. 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 .
It is the first known pterosaur to display features of both long-tailed ( rhamphorhynchoid ) and short-tailed ( pterodactyloid ) pterosaurs .