"Archaeopteryx; bird or reptile, or both?"

My answer to the original question:Archaeopteryx is what you would call a arboreal theropod. Specifically speaking, it's a dromaeosaur (think Velociraptor) because it shares a number of anatomical characters only w/ dromaeosaurs. Other features are found only in the two forms and some basal groups of birds. Some of the Archaeopteryx-dromaeosaur characters are as follows:-Nasal depressed nasal and snout upturned
-Dorsal process of maxilla almost reaches preorbital bar
-Preorbital bar slender & straight preorbital in lateral view
-Dorsal depression on the ectopterygoid
-Diamond shaped supraoccipital
-Strongly twisted paraoccipital process (noted by Currie)
-Highly modified tail with hyperdorso-flexible base (condition approached in troodonts)
-Middle finger most robust
-Ilium parallelogram shaped (also basal birds)
-Pubic peduncle very large & reversed
-Ilio-pubic articulation inverted V shape
-Pubic shafts are flat plates oriented 140 degrees to each other
-foot is functionally two toed, with a short toe II that is hyperextendable.Charater list cited from Dinosaurs of the Air : The Evolution and Loss of Flight in Dinosaurs and Birds by Gregory S. PaulYet again another image for reference. Provided by my good friend Scott Hartman of Wyoming: This message has been edited by Palaeos, 06-04-2005 12:32 AM