In recent years, scientists studying dinosaurs and birds have come to a remarkable conclusion. Not all dinosaurs vanished in the great extinction event that marked the end of the Cretaceous period and the beginning of the Tertiary period 65 million years ago. Rather, a number of small, arboreal dinosaurs of the theropod clade survived and radiated into new forms. Their descendants are still dinosaurs, and are still with us today. We call them birds.

From the beginning of dinosaur studies in the 19th century, the affinities between birds and dinosaurs have been well known. For most of that time, birds have been considered descended from or related to dinosaurs. Since about 1995, however, new discoveries have made the conclusion overwhelming, at least to most scientists, that the relationship is more direct than had been realized. Birds aren't just descended from dinosaurs - they ARE dinosaurs. Because of this realization, we registered our aviary as the Theropod Aviary in honor of the continued existence of these animals, so different from humans, that have fascinated so many of us for so long.

Here are some references which can provide more information if you find this topic as interesting as we do. We include a brief quotation from each source.

"Birds and dinosaurs share over 100 similarities in their bodies, including hollow bones; clawed, three-toed feet; unique ankle and wrist joints; and feathers. Based on the evidence, we can say that birds are not only the living descendants of dinosaurs - birds are dinosaurs. We can think of all modern birds as living, breathing, feathered dinosaurs."

Feathered Dinosaurs of China Gregory Wenzel, Charlesbridge, 2004, p. 31

Thin, children's book, well worth having for the wonderful color illustrations.

"We now tell our students that birds are card-carrying avialian, maniraptoran, coelurosaurian, tetanurine, theropod, saurischian dinosaurs, and don't you forget it! Because in doing so, you would be denying them their rightful claims to a proud and distinguished ancestry."

The Mistaken Extinction: Dinosaur Evolution and the Origin of Birds Lowell Dingus, Timothy Rowe, W.H. Freeman and Co., 1997, p. 205

A more or less personal story by the authors of their discovery - and the scientific community's discovery - of the facts about birds as dinosaurs. Also discusses the true extinction of the dinosaurs. That is, the one going on now which is largely caused by us.

"Now we must acknowledge that birds are a group of feathered theropod dinosaurs that evolved the capacity of powered flight"

"Which Came First, the Feather or the Bird?", Richard O. Prum and Alan H. Brush, "Scientific American" for March, 2003, Page 92.

An excellent article on the evolution of feathers and the creatures that use them, as well as on the development and growth of feathers on those creatures during their lives.

"While dinosaurs, as we usually think of them, died out at the end of the Cretaceous period, the class Dinosauria did not become extinct at that time. It contains more than 9,000 species of living birds, and it remains one of the most diverse groups of vertebrates alive today" p. 59

"Thanks to evidence that has come to light in recent times, we now know that dinosaurs are, in fact, not extinct. The avian members of the group survive in their highly successful descendants - the more than 9,000 species of living birds." p 87

The Time-Life Guides Dinosaurs Christopher A. Brochu, John Long, Colin McHenry, John D. Scanlon, Paul Willis, Time-Life Books, 2000

If you can obtain only one of the works mentioned on this page, this is the one to get. This is an excellent survey of all aspects of the current state of knowlege about dinosaurs. Well written, well illustrated and as up to date as a book can be. Includes a section on individual dinosaurs, and a section on the most recent finds at the time of writing.

"... we can now say that birds are theropods just as confidently as we say that humans are mammals. Everything from lunch boxes to museum exhibits will change to reflect this revelation."

"Feathers for T.REX?" by Christopher P. Sloan, "National Geographic" for November, 1999, Page 102.

Excellent article on recent discoveries involving Chinese fossils. Discusses Beipiaosaurus inexpectus, Sinonithosaurus millenii (sic), Archaeoraptor lianingensis (Note: now known to be a fake!) and an unnamed oviraptoroasaur, and their place in the lineage of theropods. There are excellent illustrations of these animals as reconstructed, as well as photos of the fossils. Perhaps the most fascinating illustration is of a down covered T.REX "chick" alongside a featherless adult.

"Let's cut to the chase: Birds are dinosaurs. As we shall see, this is not quite so radical a statement as it sounds ... "Claiming that birds are dinosaurs is no more radical than saying that humans are mammals."

The Evolution and Extinction of the Dinosaurs David E. Fastovsky and David B. Weishampel, Cambridge University Press, 1996, p. 293.

This is a college textbook, for use in Natural History courses. It is an excellent overview of dinosaur studies. Interestingly, it features a picture of Archaeopterix on the cover rather than more spectacular dinosaurs.

"To be a dinosaur, then, according to current definition within the phylogenetic system, a given animal must be a member of the group descended from the most recent common ancestor of birds and Triceratops."

Article "Dinosauria: Definition" by Kevin Padian in Encyclopedia of Dinosaurs, Edited by Philip J. Currie and Kevin Padian, Academic Press, 1997, p. 178.

This is an excellent work, covering all aspects of dinosaurs as known to about 1997. Unfortunately, it was published too soon to include much of the material on the most recent Chinese discoveries, though it does have information on Sinosauropteryx prima, the Chinese theropod covered in what is thought to be proto-feathers. That dinosaur is featured in the dust jacket illustration.

"Today a cladogram for the lineage leading from theropods to birds shows that the clade labeled Aves (birds) consists of the ancestor of Archaeopteryx and all other descendants of that ancestor. ... The cladogram shows that birds are not only descended from dinosaurs, they are dinosaurs (and reptiles) - just as humans are mammals, even though people are as different from other mammals as birds are from other reptiles."

"The Origin of Birds and Their Flight", Kevin Padian and Luis M. Chiappe, "Scientific American" for February, 1998, Page 43.

An excellent article with good illustrations of some early birds/dinosaurs. It has good, basic cladograms showing the evolution of Aves as a sub-clade of Theropoda. A more complete cladogram is available in the Encyclopedia of Dinosaurs, cited above.

"The evidence that birds descended from dinosaurs - indeed are dinosaurs - has become conclusive for most paleontologists and evolutionary biologists. ... A few scientists reject the dinosaur-bird connection. They see the similarities as convergent evolution - the development of like traits in separate species. To them dinosaurs and birds share a common ancestor (which has yet to be discovered) but evolved along separate paths. 'But they have no physical evidence,' says paleontologist Hans-Dieter Sues of Toronto's Royal Ontario Museum. 'Only dinosaurs are anatomically suited to be the precursors of birds.'"

"Dinosaurs Take Wing - The Origin of Birds", Jennifer Ackerman, "National Geographic" for July, 1998, Page 74, and many sidebars to this article.

The quote above is from a two page sidebar called "There's a Dinosaur in Your Backyard", page 96. This issue has many excellent illustrations, including photos of fossils, charts, and models of reconstructed dinosaurs.

"If the dinosaur-bird link was convincing before, it's now pretty close to rock solid."

"Dinosaurs of a Feather", Michael D. Lemonick, "Time" for July 6, 1998, Page 82.

Short but well written article, with a good illustration of Caudipteryx.