The Paleozoic Era was a major chapter in Earth’s history when marine ecosystems expanded, plants spread across continents, forests developed, and vertebrates gradually moved onto land. It began with the Cambrian Period and ended with the Permian Period, covering more...
Ceratopsia was a diverse group of herbivorous dinosaurs known for their strong beaks, unusual skulls, and, in some members, large horns and bony frills. The group included small early forms such as Psittacosaurus as well as famous later dinosaurs such as Triceratops...
Amniota is a major group of land vertebrates that includes reptiles, birds, and mammals. Amniotes are distinguished by an evolutionary development called the amniotic egg, which allowed embryos to develop with greater protection from drying and other environmental...
Monotremes are a small and unusual group of mammals that lay eggs instead of giving birth to live young. The living monotremes are the platypus and echidnas, which are found naturally in Australia and New Guinea. Although they reproduce differently from most other...
Sarcopterygii is a major group of vertebrates commonly known as the lobe-finned fishes. Their fins contain fleshy, muscular bases supported by internal bones, making them different from the thin, ray-supported fins of most ray-finned fishes. The group includes living...
Chordate Phylum includes a diverse group of animals that share a distinctive set of features during at least one stage of their development. These features include the notochord, dorsal hollow nerve cord, pharyngeal slits, endostyle or thyroid-related structure, and...
