Many marine animals became extinct during the Permian, but there was at the same time an evolution to more modern types, a marked change in the insects, and a notable increase in numbers and varieties of reptiles mainly because of the continental changes. Among plants, Lepidodendron and Sigillaria became rare, but ferns and conifers persisted. The widely distributed "seed fern," Glossopteris, which was apparently successful in resisting glacial conditions, was the most conspicuous development in the Permian flora. The presence of Glossopteris in South America, Antarctica, Australia, and S Africa is a strong argument favoring the interconnection of these land masses in a large supercontinent during Permian time. The end of the Permian is marked in the fossil record by the most devastating mass extinction known.