Page 152 - The Transitional Form Dilemma

THE TRANSITIONAL-FORM DILEMMA

leged Theropod ancestors, revealing that there was no similarity be-
tween them. 122
Similarities between this creature and dinosaurs suggested by
John Ostrom, one of the most eminent authorities to claim that
Archaeopteryx evolved from dinosaurs, were revealed by such
anatomists as S. Tarsitano, M. K. Hecht and A. D. Walker to be false in-
terpretations. 123

4. Archaeopteryx’s ear structure: A. D. Walker studied the ear
structure of Archaeopteryx and stated that it was the same as that in pre-
sent-day birds. 124

5. Archaeopteryx’s wings: J. Richard Hinchcliffe of the University
of Wales Biological Sciences Department used modern isotopic tech-
niques in his study of embryos and established that the three dinosaur
digits on the forelimbs are I-II-III, whereas bird wing digits are II-III-IV.
This is a major difficulty for the proponents of the so-called
Archaeopteryx-dinosaur link. 125 Hinchcliffe’s research and observations
were carried in the famous magazine Science in 1977:
Doubts about homology between theropod and bird digits remind us of some of
the other problems in the “dinosaur-origin” hypothesis. These include the follow-
ing: (i) The much smaller theropod forelimb (relative to body size) in comparison
with the Archaeopteryx wing. Such small limbs are not convincing as proto-
wings for a ground-up origin of flight in the relatively heavy dinosaurs. (ii)

Drawing of a thero-
pod dinosaur

150