T Rex

How many types of dinosaurs are known?

Approximately 700 species have been named. However, a recent scientific review suggests that only about half of these are based on fairly complete specimens that can be shown to be unique and separate species. These species are placed in about 300 valid dinosaur genera (Stegosaurus, Diplodocus, etc.), although about 540 have been named. Recent estimates suggest that about 700 to 900 more dinosaur genera may remain to be discovered.

Most dinosaur genera presently contain only one species (for example, Deinonychus) but some have more (for example, Iguanodon). Even if all of the roughly 700 published species are valid, their number is still less than one-tenth the number of currently known living bird species, less than one-fifth the number of currently known mammal species, and less than one-third the number of currently known spider species.

Return to Dinosaurs: Facts and Fiction
This page is URL:http://pubs.usgs.gov/gip/dinosaurs/types.html
For more information, please contact Robert Weems at rweems@usgs.gov or Ronald Litwin at rlitwin@usgs.gov.

Maintained by Publications Services.
Last modified 05-17-01 (krw)