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Jehol Biota exhibit in Vancouver
From: Ben Creisler bh480@scn.org
Took a quick one-day trip up to Vancouver, British
Columbia, last Saturday to see the "Jehol Biota" exhibit
of specimens from the private collection of Du Wenya, who
runs a museum in Jinzhou, China. (The exhibit at the
Vancouver Convention and Exhibition Centre ends 12-23-02.)
Apparently the Chinese government will not allow such
exhibitions of private specimens in the future so this
show is a rare event. According to a story in the
Vancouver Sun, some of the specimens are new to Western
scientists. Most notable for purposes of the Dinosaur
Mailing List were three specimens identified only
as "dromaeosaurs"--based on some obvious differences in
limb proportions, they would appear to represent at least
three distinct taxa but maybe not "new" taxa in every
case. Also on display were around a dozen specimens of
Confuciusornis (including the holotype of Confuciusornis
dui and another specimen that is clearly NOT
Confuciusornis despite the label) and around a half-dozen
specimens identified as Liaoxiornis. Other items include
specimens of Psittacosaurus (one beauty (D:058) has
gastroliths in situ in the gut region), many fossils of
the diapsid Hyphalosaurus (mislabled "Hyphiosaurus"
throughout), plus amphibians, fish, insects and plants.
Sorry to say I can't give a detailed Tom-Holtzian analysis
of the dromaeosaurs, but here is some basic info. Catalog
numbers are for the Wenya Museum:
Dromaeosaurs:
All three of these theropods have caudals bearing very
long thin processes to stiffen the tail and two specimens
at least have an enlarged claw on the 2nd toe. The dates
on the labels are "Late Jurassic" but the fossil almost
certainly date to the Early Cretaceous instead. Nicknames
are mine.
DNO: 087 "Long femur"
A virtually complete and apparently undoctored specimen
around 64 cm long with a complete but crushed and somewhat
jumbled skull. The femur is about 1.25 times the size of
the tibia. Outline of filaments are visible in the pelvic
region and possibly elsewhere. My hunch is that this one
may be a Sinornithosaurus, but I'll need to check the
original description.
DNO: 088 "Long Tibia"
An incomplete specimen apparently from a single
individual, preserving the skull, forelimbs, hindlimbs and
tail, but most of the trunk section is missing. It was
displayed in a large case so close examination was not
possible. The tibia is about 1.25 times longer than femur.
Femur and metatarsals about equal in length. Humerus and
ulna about equal in length. Manus disarticulated. The
crushed skull was hard to decipher from a distance. Based
on the limb proportions this is not the same as DNO: 087,
and I won't guess if it's a known or new taxon. It also
appears somewhat smaller than the possible
Sinornithosaurus specimen above.
D: 090 "Short Metatarsals"
I have strong suspicions about this one, even though its
photo is part of the hand-out brochure. The feet are
definitely doctored and lack a large slashing claw despite
the "dromaeosaur" label. John Hutchinson has a quick
description of some Wenya specimens on the web (see
http://www.geocities.com/CapeCanaveral/Hangar/6878/sape.htm
l). He mentions a chimaeric dromaeosaur with
Confuciusornis feet. This may be the same specimen, though
I didn't see any obvious preserved filaments anywhere on
the specimen. The metatarsals appear abnormally short and
the feet are almost preposterously dainty for the rest of
the animal. The matrix is clearly repaired and glued in
the vicinity of the feet. The rest of the body is also
odd, with one arm at least having extremely long radius
and ulna and no preserved hand bones--the other arm has
part of the radius and ulna missing and the manus mangled.
The skull appears to have teeth only in the front of the
jaws instead of along the length of the jaws. An expert
may have to sort out the avian from the non-avian parts
before much can be said about this one.
-----
Birds:
Many excellent fossils of Confuciusornis representing
different growth stages and presumably sexes (one slab has
two individuals, one with two very long display feathers
on the tail, the other without), and at least two species
(C. sanctus and C. dui). Many have very well preserved
wing feathers. It's staggering to think that there may be
thousands of virtually complete fossil specimens of this
ancient bird.
One specimen (BNO: 081) labled "Confuciusornis sanctus"
has teeth, and a manus with a third digit shorter than the
second--all three digits were not nearly as robust and
heavily clawed as the typical Confuciusornis manus while
the feet had very large claws, again unlike
Confuciusornis. I'll need to check Hou's book, but this
one is probably a known enantiornithine.
The multiple Liaoxiornis specimens are of particular
interest since previously this taxon was known from a slab
and counterslab given different names. Of particular note
was a specimen (B: 077) labeled Liaoxiornis with a
question mark, that preserves two large tail feathers
extending beyond the relatively long bony tail. Maybe such
double tail feathers (known from much longer examples in
Confuciusornis and maybe Jibeinia) were typical sex-
markers in mature male Mesozoic birds. Another very tiny
specimen (obviously juvenile) was preserved on a slab and
counterslab ( B:066 and B:067).
-----
The insect fossils are quite impressive, not only for the
size of some bugs but for the excellent preservation. It's
a bit strange that insect fossils are actually rarer than
vertebrate fossils, since insects obviously have
outnumbered vertebrates since the Carboniferous. A nice
specimen labeled Kalligrama (MN: I129) preserves the
classic big eyespot pattern found on some modern insect
wings. Apparently the image of big eyes worked to make
pterosaurs, primitive birds and small dinosaurs think
twice.
Other specimens of particular note included some parts of
Archaefructus, one of the earliest known flowering plants,
the frog Callobatrachus (with muscles preserved) and the
salamander Liaoxitriton.
I avoided the guided tour--the Anglo guide was obviously
enthusiatic about the exhibit but made up much of his
spiel out of thin air. Overheard quotes included a
description of Psittacosaurus as a "tree-hopper" (not
impossible I guess but certainly not a "fact") and
something about a new specimen of T. rex from Montana
from the "Late Jurassic" that had "a diaphronous
extension" that showed it was trying to evolve. People
appeared to eat it up. The labels were annoyingly garbled,
with names of taxa mispelled and some loopy English
translations that must have been run through a computer
translation program.
Still, the best fossils on display are so amazing in their
completeness and preservation of detail that it's hard to
be a quibbler over defects and shortcomings in the
presentation.