Archaeopteryx part 2
Let's say we decide that the bone structure of the
Archaeopteryx is definitely reptilian, from which line of reptiles
is it related? Surely, there would be traces of one or the other.
Martin, Stewart, and Whetstone, "The Auk" (Ornithological Journal)
January 1980 page 86 "The Origin of Birds: Structure of the Tarsus
"...virtually every major group of reptiles has been
purported to be closely related, if not ancestral to birds."
In the report they briefly mention two hypotheses concerning
Archaeopteryx and proceed to push their own- crocodile ancestry
based on teeth. The hypotheses are:
1) A theory of their ancestry from Triassic pseudosuchian
2) A theory of direct derivation of birds from theropod
3) A close relationship between birds and crocodilians.
It should be noted that in their report that altho' they
concentrated on the Archaeopteryx, the authors clearly related the
teeth of this bird to the teeth of later Mesozoic birds and spoke
of them as one in the same. They were mainly dealing with the
origin of teeth in all teeth-bearing birds.
In another report that I mentioned a while back in "Nature"
Sept 8 1983 pp99-100 entitled "No consensus on Archaeopteryx" The
author Dr. Michael Benton (not to be confused with Dr. Michael
Denton) concerning the different theories:
" The relationships of Archaeopteryx and the origin of the
birds are controversial. In a recent review, Thulborn and Hamley
identified seven hypothses concerning the affinities of
Archaeopteryx, three of which appear to have supporters at
Just prior to this, Dr. Benton discusses the results of
Archaeopteryx cranial studies:
"In the new work that has been done on the braincase of
Archaeopteryx by Whetstone, the cranium of the 'London'
specimen has been removed from its limestone slab and painstakingly
prepared by mechanical means.
This has shown that the skull is much broader
and more bird-like than had been thought. Details of
the braincase and associated bones at the back of the skull seem
to suggest that Archaeopteryx is not the ancestral bird, but an
off-shoot from the early avian stem." He goes on for the rest of
the paragraph discussing very briefly how it is primitive in some
respects and advanced in others. But basically the Archaeopteryx
has been, according to him, relagated from the lofty position of
being the transition between reptile and modern bird to that of
just another "side branch" of evolution.
So you see, the reptilian features of the Archaeopteryx are
so obscure and ambiguous that trying to pin down its ancestral
relationship is just about impossible. Forcing the Archaeopteryx
into the role of transition has proved to be nothing but a
But let's say for the sake of arguement that the
Archaeopteryx's bony structure can be related to reptiles as well
as birds. Does this still necessarily force us to conclude that
it is transitional?
"Evolution: Nature and Scripture in Conflict?" by Dr. P.T.
Pun copyright 1982
Archaeopteryx has been cited frequently as the transitional
type between reptiles and birds. It has a birdlike skull and wings
with feathers. The reptile features are presented by clawlike
appendages, the possession of teeth, and the long vertebral column
that extends to the tail. The flying power of this organism was
presumably slight, for the wingspread is much less than that of
the poor flyers among modern birds.
Since most skeletal features of birds can be matched by some
archosaurian reptiles, feathers have been considered the only
distinctive feature of birds. Feathers are essential to birds for
insulation against loss of body heat, and this contrasts greatly
with reptiles since they are cold-blooded. Therefore,
Archaeopteryx was definitely bird.
However the presumed small sternum, the
primitive reptilian structure of wing bones, and
especially the long tail set Archaeopteryx apart from most modern
birds, requiring a separate subclass to represent it. However,
some reptilian structures of this fossil are shared by some
modern-day birds. For example, the juvenile stages of
Opisthocomus hoatzin of South America and Touraco cory thaix of
Africa possess claws, and both are flyers...
...More specifically, L. de Nouy, an evolutionist, commenting
on the status of Archaeopteryx has made a very succinct statement
concerning the establishment of "true links" between major groups.
While recognizing the morphological similarities of Archaeopteryx
to reptiles and birds, he nevertheless concluded:
"By link, we mean a necessary stage of transition
between classes such as Reptiles and Birds, or between
smaller groups. An animal displaying characters belonging to
two different groups can not be treated as a true link as
long as the intermediary stages have not been found, and as
long as the mechanism of transition remains unknown."