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Stephan Pickering
wrote-
If one carefully reads Ernst Stromer's original German
papers, it is clear there is more than one individual being described (as the
specimens are lost, speculations re: another genus are akin to giving taxonomic
status to individual snowflakes), and the elongate neural spines have no
centra.
Uh, I was pretty sure at
least one of the neural spines was found with centrum attached, or (as the
neurocentral sutures are unfused) at least fit together so well with the centrum
(also taking their proximity into account) that it certainly belongs.
There is not much evidence the holotype of Spinosaurus aegyptiacus
(skull fragments, vertebrae, ribs) is made of portions of multiple individuals,
although Spinosaurus B is apparently Carcharodontosaurus. Rauhut thinks
Spinosaurus is an allosauroid, with the cranial remains belonging to an unnamed
"baryonychid", which is possible I suppose. Still, his evidence didn't
seem very strong.
To state, as Jack Horner has done, that Spinosaurus
probably had an eight foot long skull is based upon no known evidence, as is
his idea the animal was 19 feet 7 inches high (including the "fin") and 43 feet
9 inches long.
Regarding Spinosaurus' size,
as I've said before-
If we assume the dorsals are from a relative of
baryonychines (contra Rauhut 2000), we can use their size to estimate that of
Spinosaurus. Suchomimus has a more complete tail than Baryonyx and
measured 11.0 meters long. Scaling the humerus to Baryonyx indicates a
length of 9.1 meters for the latter taxon, very close to Charig and Milner's
(1997) estimate of nine meters. Nearly all the dorsals are preserved in
Baryonyx, increasing in length to the last, which is 110 mm long. The
largest and most posterior of Spinosaurus' dorsals (dorsal i of Stromer 1915) is
about 210 mm long. Scaling this to Baryonyx's last dorsal (scaling to more
anterior dorsals would give greater lengths) gives an estimated length of 17.4
meters for the holotype of Spinosaurus aegyptiacus. This is equivalent to
57 feet, so I think Horner was very accurate in his report. Keep in mind
the holotype is immature as well, so adults were probably
longer.
I am trying to be diplomatic: the 1915-2001 idea of
Spinosaurus being an enormous theropod, with a Dimetrodon-like sail on its back, cannot be substantiated with any articulated skull
and skeleton,
Articulated, no. But
the cranial and vertebral remains are certainly of an
enormous theropod. The idea it has a sail is certainly controversial,
with me personally liking the hump idea, but that's been discussed to death on
the list.
Coupled with this is the unfortunate use of "Spinosauridae" in
various cladistic analyses, a nomenclatural chimera, as Spinosaurus remains a
nomen dubium (along with Therizinosaurus).
Spinosaurus a nomen dubium?!!!!!
Ha! And Therizinosaurus a nomen dubium?!!!!!! Ha again! I'd like you
to find another animal in the world with those dorsal neural spines and manual
unguals respectively.
Mickey
Mortimer
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