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Todd Marshall wrote-
I was wandering if any of you kind souls could
please help me out? I'm getting ready to work on an illustration for a
client, of Bahariyasaurus ingens. I'm aware that the specimen type was destroyed
in WW II, a femur, fibula and some postcranial elements if I'm not
mistaken. I was reading in Gregory S. Paul's book PDW, that this therapod was
put into the megalosaur group, but there were aspects of the bones gracility
that make it very tyrannosaur-like. Has there been any new fossils or evidence
on this animal unearthed? Any information on this animal would be greatly
appreciated. Any size and length estimations to reconstruct this animal
would also help a lot.
First of all, the remains of Bahariasaurus are not
nearly complete enough for a restoration in my opinion. Information on the
holotype-
holotype- (IPHG 1922 X47) dorsal vertebra
(200 mm), dorsal vertebra (~180 mm), neural arch, rib fragment, sacral vertebra
(~135 mm), sacral vertebra (~120 mm), sacral vertebra (~120 mm), pubes (1.03 m),
proximal ischium
If we compare the pubic length to that of
Allosaurus, we get a length of 11 meters and a mass of 3.5 tons.
The specimen including the femur and fibula
(IPHG 1912 VIII) was referred to Deltadromeus by Sereno (1996).
Bahariasaurus differs from Deltadromeus in- broader pubic shaft; pubic foot
divided in the midline; iliac peduncle of ischium narrower. However, I
have heard from good sources that the supposed pubis of Deltadromeus is really
an ischium, rendering the first two characters moot. Is the narrower iliac
peduncle reason enough to keep these two genera separate? So on the one
hand, you have a situation where Bahariasaurus could be synonymous with
Deltadromeus, which is non-tyrannoraptoran, and possibly
non-coelurosaurian.
Rauhut (1995) did a study on
Carcharodontosaurus and Bahariasaurus where he considered the latter a member of
the Carcharodontosauridae within the Allosauroidea. This was before the
description of Deltadromeus, so he included IPHG 1912 VIII in
Bahariasaurus. I unfortunately lack this paper, but the summary in Glut's
encyclopedia indicates at least some proposed carcharodontosaurid synapomorphies
are determinable in the holotype (pubic symphysis reduced proximally and
distally; pubis bowed anteriorly; obturator process offset from pubic
peduncle). Whether these are actually characteristic of Bahariasaurus and
Carcharodontosaurus (and perhaps Giganotosaurus and Acrocanthosaurus) would
require an analysis beyond the scope of this post. Thus we have a second
possibility for Bahariasaurus- that it's a carcharodontosaurid
carnosaur.
I can't recommend one possibility over the
other at the moment, but you can see why I don't think a reconstruction is a
good idea at this point.
Mickey
Mortimer
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