Definition of float in the AudioEnglish.org Dictionary. Meaning of float. What does float mean? Proper usage and pronunciation (in phonetic transcription) of the word float. Information about float in the AudioEnglish.org dictionary, synonyms and antonyms.
Mammals evolved from a group of mammal-like reptiles called the Synapsids, specifically the Therapsids, in the Triassic period, around 250 million years ago.
By the time the first mammals evolved 200 million years ago, however, dinosaurs were the dominant vertebrates. Mammals diversified in the shadow of the great archosaurs, and they remained fairly small and secretive until the non-avian dinosaurs were wiped out by a mass extinction 65 million years ago.