| Nembrionic |
03-24-2005 03:52 PM |
Quote:
Originally Posted by GatorB
Dinosaurs were NOT reptiles. In fact birds are the direct descendants of dinosaurs.
|
uh-huh
Definition
The superorder or clade "Dinosauria" was formally named by the English scientist Richard Owen in 1842. The term is a combination of the Greek words deinos ("terrible" or "fearfully great" or "formidable") and sauros ("lizard" or "reptile"). Contrary to popular perception, the name was chosen to express Owen's awe at the size and majesty of the extinct animals; not out of fear or trepidation at their size and formidable arsenal.
There is an almost universal consensus among paleontologists that birds are the descendants of theropod dinosaurs. Using the cladistic definition (all descendants of a single common ancestor), modern birds are dinosaurs, and dinosaurs are therefore not extinct:
"Ask your average paleontologist who is familiar with the phylogeny of vertebrates and they will probably tell you that yes, birds (avians) are dinosaurs. Using proper terminology, birds are avian dinosaurs; other dinosaurs are non-avian dinosaurs, and (strange as it may sound) birds are technically considered reptiles." [3] ( http://www.ucmp.berkeley.edu/diapsids/avians.html)
However, birds are morphologically quite distinct from their reptilian ancestors, and referring to birds as "avian dinosaurs" and all other dinosaurs as "non-avian dinosaurs" is clumsy. Birds are still birds, at least in popular usage and among ornithologists. It is also technically correct, at least under the older Linnaean classification system, which accepts taxa that exclude some descendants of a single common ancestor (paraphyletic taxa).
As a result, this article uses "dinosaur" as a synonym for "non-avian dinosaur", and "bird" as a synonym for "avian dinosaur". |
