Please do not plagiarize.
If you would like to use this information in a print or electronic publication, please ask me for permission first and cite this page as:
Classes of the Subphylum Vertebrata (Vertebrates)
Please note: Many authors arrange classifications differently, especially with extinct taxa.
For example, since birds are considered by many to be descended from the dinosaurs, which were reptiles, the dinosaurs would be more closely related to the birds than to other reptiles. Therefore either Aves would have to placed under Reptilia, or Reptilia would have to split into several classes. By this scheme, the birds, dinosaurs and crocodilians are grouped into the taxon Archosauria, and the archosaurs and remaining reptiles make up the taxon Diapsida.
Likewise some authors place the order Enantiornithiformes under the superorder Odontognathae instead of the subclass Enantiornithes. Others would place Hesperornithiformes and Ichthyornithiformes in their own superorder or subclass rather than under Odontognathae.
Eutheria is sometimes considered an infraclass under the subclass Theria.
Agnatha, Chondrichthyes and Osteichthyes were once considered one class: Pisces. Some authors now use Pisces to mean Osteichthyes.
Since I am by no means an expert, the classification depicted here is not meant to imply my preference, but rather shows only one of the many possibilities now being debated.Sources:
Kingdoms | Phyla
Copyright © 1995-2002 Robbin D. Knapp email@example.com.