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.
Large reptiles were beginning to be replaced by mammals as the dominant large land animals. Among the mammals, there were a few archaic egg-layers like the ancestors of the platypus and echidna. There were larger numbers of pouched opossum-like mammals . The few placental mammals that existed at that time mainly consisted of the Insectivore ancestors of primates.