In contrast , Dolichosaurus longicollis , the only species of Dolichosaurus , is known from postcranial skeletons with only very fragmentary skulls and no teeth .
Both known species of Coniasaurus , C. gracilodens and C. crassidens , are known from disarticulated skulls with isolated vertebral elements .
Dolichosaurus longicollis , the only species of Dolichosaurus , is known from postcranial skeletons with only very fragmentary skulls and no teeth .
Both known species of Coniasaurus , C. gracilodens and C. crassidens , are known from disarticulated skulls with isolated vertebral elements .