genus Psilophyton
— Navneord
– Engelsk
~ type genus of the Psilophytaceae: genus of small wiry herbaceous Paleozoic plants with underground rhizomes and apical sporangia
genus Psilotum
— Navneord
– Engelsk
~ type genus of the Psilotaceae
genus Psithyrus
— Navneord
– Engelsk
~ a large bee that resembles the bumblebee but lacks pollen-collecting apparatus and a worker caste
genus Psittacosaurus
— Navneord
– Engelsk
~ most primitive genus of horned dinosaurs; early Cretaceous