title: Penis worm dragged itself round by its teeth!
mesh_terms: D000818:Animals; D005580:Fossils / Q000033:anatomy & histology*; D049690:History, Ancient; D007448:Invertebrates / Q000033:anatomy & histology*; D008124:Locomotion; D014070:Tooth / Q000033:anatomy & histology* / Q000502:physiology