The dinosaurs originated from diapside reptiles which survived the mass-extinction at the end of the Permian as swimming archosaurs. From those emerged bipedal archosaurs, among others two groups of bipedal herbivores, the short-necked ancestors of the ornitischian dinosaurs, and long-necked ancestors of the saurischian sauropods. Later emerged the short-necked meat-eaters, ancestors of the carnosaur dinosaurs. From a lineage of small bipedal, tree-mounting bird-ancestors the various groups of bird-like, coelurosaurs branched off. The dinosaurs disappeared as …showed first 75 words of 4656 total…

…showed last 75 words of 4656 total…sea decreased which upset the ecological balance of the sea too: The algae were food for other sea-organisms, which were food for fishes and other see-animals, which also decreased, why the lope-finned fishes and the see-reptiles, ichthyosaurs, plesiosaurs, mesosaurs ect. consequently disappeared. These factors, and surely many others, brought the world of the dinosaurs to an end, leaving a world covered with foliated forests, and the possibility for the small, warm-blooded mammals to evolve.