Character Details
torpedo-shaped body
torpedo-shaped body (convergent with sharks, tuna, etc.) for fast swimming
front flippers
addition of many small bones in hands, forming large front flippers for steering during swimming
very large orbit
very large orbit (eye socket), along with many other skull modifications
+-Deuterostomata
+-Echinodermata
+-Hemichordata
+-Chordata
+-Urochordata
+-Cephalochordata
+-Craniata
+-Mixinoidea
+-Vertebrata
| +-Hyperoartia
| +-Jawless Fishes
+-Gnathostomata
+-Placodermi
+-Chondrichthyes
+-Teleostomi
+-Acanthodii
+-Osteichthyes
+-Actinopterygii
+-Sarcopterygii
| +-Coelacanthimorpha
| +-Dipnoi
+-Tetrapoda
+-Amphibia
+-Amniota
+-Synapsida
| +-Primitive Synapsids
| +-Mammalia
| +-Monotremata
| +-Marsupialia
| +-Eutheria
| +-Edentata
| +-Glires
| +-Archonta
| +-Insectivora
| +-Carnivora
| +-Ungulata
+-Reptilia
| +-Testudines
+-Diapsida
+-Primitive Diapsids
+-Sauria
+-ICHTHYOSAURIA <<<<< Taxon for this page
+-Sauropterygia
+-Lepidosauromorpha
+-Archosauromorpha
+-Crocodylomorpha
+-Pterosauria
+-Dinosauria
