Azhdarcho: Palaeoart by Matt Martyniuk.
Cenozoic Life: A Yahoo group covering organisms from the Cenozoic. Created and maintained by Neal Robbins.
Dinodata: One of the best dinosaur resources on the web.
Dinosaurpalaeo: Blog by Heinrich Mallison on dinosaur palaeontology.
Dinogoss: Blog on dinosaurs by Matt Martyniuk.
Dinosaur Mailing List: Dinosaur discussion board.
Dinosaur Central: A site devoted to dinosaurs.
Dinosaurier-info: A German site devoted to dinosaurs by Uwe Jelting.
Dinosaurs on Stamps: A list of stamps featuring dinosaurs by Robert Margulski.
Dinosaurs and Other Mesozoic Creatures: A Yahoo group devoted to all things Mesozoic. Created and maintained by Neal Robbins.
Dracovenator: A scientific blog by palaeontologist Adam Yates. A great website entirely devoted to a group of Palaeozoic invertebrates, the eurypterids (or sea scorpions), by Samuel Ciurca.
Ferocious Fighting Dinosaurs: A group devoted to all things dinosaur, esp. theropods.
Green Tea and Velociraptors: Jon Tennant's blog on all things Palaeo.
Love in the Time of Chasmosaurs: A blog on dinosaurs and other Mesozoic creatures, by David Orr.
Mikko's Phylogeny Archive: The phylogeny website of Mikko Haaramo.
Ocean of Kansas: A website devoted to the fauna that lived in the Western Interior Sea during the Cretaceous period.
Ontograph Studios Image Library: A collection of the most scientifically rigorous prehistoric animal depictions found on the net, maintained by John Conway
Palaeocast: To facilitate the communication of palaeontological knowledge through use of an increasingly popular platform, from which an academic can convey ideas at a level, and in a medium, accessible to the interested public.
Palaeos: The trace of life on earth.
Paleoexhibit: Blog by Nobu Tamura.
Paleobiology database: An extensive multi-authored database on the fossil record.
Panda's Thumb: A multi-authored blog on evolution.
Pharyngula: A scientific blog by biologist P.Z. Myers.
PhyloPic: An open database of organism silhouettes by T. Michael Keesey. A fantastic website devoted entirely to... you guessed it pterosaurs!
Skeletaldrawing: A great website devoted to skeletal reconstructions of several dinosaurs by Scott Hartman.
Tetrapod Zoology: A scientific blog by palaeontologist Darren Naish.
The Pterosauria: The pterosaur database by Mike Hanson.

Thescelosaurus: Dinosaur database by Justin Tweet.
The Theropod Database: A complete list of theropods provided by Mickey Mortimer.
The Palaeobabbler: Blog on palaeontology, evolution & much more by Jason Sherburn.
U.K. Amateur Fossil Hunters: Website devoted to British fossil hunting, discuss fossils, view others and more.
Wikidino: A comprehensive encyclopaedia on dinosaurs.