rekiny-i-płaszczki: Chordate

Evidence: 55 • authority: 72

Vertebrates (), also called craniates, are animals with a vertebral column and a cranium. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata ( VUR-tə-BRAY-tə) with some 65,000 species, by far the largest ranked grouping in the phylum Chordata. The vertebrates include mammals, birds, amphibians, and various classes of fishes and reptiles. The two major living vertebrate subgroups are the jawless Cyclostomi (including hagfish and lampreys), and the jawed Gnathostomata. The jawed fish include both the cartilaginous fish and the bony fish. Bony fish include the lobe-finned fish, which gave rise to t…

Evidence: 55 • authority: 72

Evidence: 41 • authority: 72

Evidence: 41 • authority: 88

Evidence: 41 • authority: 92

Evidence: 41 • authority: 72

Evidence: 41 • authority: 72

Animals are multicellular, eukaryotic organisms belonging to the biological kingdom Animalia (). Animals consume organic material, breathe oxygen, have muscle cells, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. With few exceptions, animals are able to move. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.…