INACCURATE ARCHAEOPTERYX SKULL IN NATURE

[GSP1954@aol.com]

In the Oct 9 Nature Martin & Zhou published a restoration of the skull of
Archaeopteryx which contains some inaccuracies.

For one thing, they fail to show a well developed and complete squamosal and
upper temporal bar behind the orbit. Elzanowski & Wellnhofer (1995, 1996 JVP)
have shown that the former is well preserved in the newest specimen (which
was on display in Chicago during SVP, alas under glass). The squamosal has a
well developed articulation for the postorbital, and fragments of the latter
are preserved. So the bar must have been complete. 

The restoration also shows the quadrate vertical (so did I in PDW). However,
the quadrate always slopes strongly down and forwards in the specimens (most
so in the Berlin specimen, also the Eichstatt and newest specimen). This is
like some of the new primitive Cretaceous birds. It is also like
ornithomimids. 

M & Z assert that the short dorsal process of the jugal was too far back to
articulate with the postorbital, so the postorbital bar must be incomplete.
This is true only if the quadrate is  vertical. When the quadrate is
procumbent the process of the jugal is in the correct position to contact the
postorbital. In ornithomimids the dorsal process of the jugal is also short,
yet it contacts the postorbital. So the same may be true in Archaeopteryx. On
the other hand the new juvenile Early Cretaceous bird (Sanz and 9 other
authors, Science June 6 97) has an incomplete postorbital bar in which a long
postorbital ventral process barely fails to contact the jugal. Maybe the same
was true in the urvogel. 

The quadrate is restored inaccurately, they confuse the quadrate ramus of the
pterygoid for part of the quadrate. 

It is interesting that the Cathayornis skull M & Z describe has auxiliary
antorbital fenestrae like those of Archaeopteryx. Interesting because Martin
earlier denied that these were present in the latter. Also interesting
because this shows that early birds had well developed maxillary sinuses of
the type limited to tetanuran avetheropods! Yet more evidence that birds are
dinosaurs. This also falsifies the lizard-like nasal passage restored for
Archaeopteryx by Ruben. 

Over all the skull of Archaeopteryx is still that of a dinosaur, and is not
as birdy as M & Z show. 

GSPaul