the first group of animals to live on land was the
Evolutionary history of life Ediacara biota appear during the Ediacaran period,[37] while vertebrates, along with most other modern phyla originated about 525 Ma during the Cambrian explosion.[38] During the Permian period, synapsids, including the ancestors of mammals, dominated the land,[39] but most of this group became extinct in the Permian–Triassic extinction event 252 Ma.[40] During the recovery from this catastrophe, archosaurs became the most abundant land vertebrates;[41] one archosaur group, the dinosaurs, dominated the Jurassic and Cretaceous periods.[42] After the Cretaceous–Paleogene extinction event 66 Ma killed off the non-avian dinosaurs,[43] mammals increased rapidly in size and diversity.[44] Such mass extinctions may have accelerated evolution by providing opportunities for new groups of organisms to diversify.[45]
Zoo The predecessor of the zoological garden is the menagerie, which has a long history from the ancient world to modern times. The oldest known zoological collection was revealed during excavations at Hierakonpolis, Egypt in 2009, of a ca. 3500 BCE menagerie. The exotic animals included hippopotami, hartebeest, elephants, baboons and wildcats.[9] King Ashur-bel-kala of the Middle Assyrian Empire created zoological and botanical gardens in the 11th century BCE. In the 2nd century BCE, the Chinese Empress Tanki had a "house of deer" built, and King Wen of Zhou kept a 1,500-acre (6.1Â km2) zoo called Ling-Yu, or the Garden of Intelligence. Other well-known collectors of animals included King Solomon of the Kingdom of Israel and Judah, queen Semiramis and King Ashurbanipal of Assyria, and King Nebuchadnezzar of Babylonia.[2] By the 4th century BCE, zoos existed in most of the Greek city states; Alexander the Great is known to have sent animals that he found on his military expeditions back to Greece. The Roman emperors kept private collections of animals for study or for use in the arena,[2] the latter faring notoriously poorly. The 19th-century historian W. E. H. Lecky wrote of the Roman games, first held in 366 BCE: