V. brevirostris is known from the holotype FMNH UC 644, a three-dimensionally preserved nearly complete and articulated skeleton including a nearly complete skull and mandibles. It was collected in the Indian Creek, 35 site (=Cacops Bonebed), from the Arroyo Formation of the Clear Fork Group, Baylor County of Texas, dating to the early Kungurianstage of the Cisuralian Epoch, about 279.5-272.5 million years ago. Many well preserved specimens from the same locality and horizon of the type specimen, including FMNH UR 2423, nearly complete skull and mandibles, MCZ 1926, complete skull and mandibles and FMNH P 12841, partial skeleton, are referred to V. brevirostris. One articulated skeleton with bite marks was found in southwest of Abilene (Arroyo Formation), Taylor County of Texas. Specimens