The Chordata is the animal phylum with which everyone is most intimately familiar, since it includes humans and other vertebrates. However, not all chordates are vertebrates. Any animal that has a spinal cord is a chordate. This group covers most of the creatures you see at home or in zoos, and most of the meat and sh that you might eat, and it includes you, too. All chordates produce eggs which turn into babies. These are some types of chordates: Fish, Amphibians (frogs), Reptiles (lizards, snakes, dinosaurs), Mammals (rats, dogs, cows, monkeys, gira es, people), Birds. The evolutionary relationships between the chordate groups and between chordates as a whole and their closest deuterostome relatives have been debated since 1890. Studies based on anatomical, embryological, and paleontological data have produced di erent "family trees". Combining such
analyses with data from a small set of ribosome RNA genes eliminated some older ideas, but opened up the
possibility that tunicates (urochordates) are "basal deuterostomes", surviving members of the group from which echinoderms, hemichordates and chordates evolved.