Bernie’s got
Teeth!!! – and other finds
This report covers the period from May 18th to
June 17th, 2013
The highlight of this period, as noted above, is that a
fragment of jaw with imbedded teeth has been found! This means that we do have
some of Bernie’s skull, even if in fragments, and the teeth are certainly
diagnostic. The teeth are imbedded in
their own individual sockets . This dental structure is termed Ichthyosaur
Thecodont (R Motani) . We don’t know if the teeth are fused to the jawbone at
the bottom or not – it will take an X-ray or CAT scan to determine that.. This
is unusual for Ichthyosaurs, where the teeth are usually imbedded in a long
groove along the jawbones especially for all Jurassic and Cretaceous
Ichthyosaurs. The broken face of the bone was actually exposed on the surface
of the concretion, so we know it’s long gone. In the picture below, the left
side of the jaw is the distal end of the jaw – end furthest away from the
skull.
Having the teeth in individual sockets limits Bernie’s families to the known Cymbospondylus and Shonisaurus or an unknown lineage. Both of these are found in Triassic Nevada though the Cymbospondylus has not been found in the Carnian age, which Bernie’s formation is dated.
One side of the jaw has some funny-looking bone, rather
porous and irregular. It may be some preserved cartilage or who knows – old
injury site perhaps?
Other great finds worked on this period is a possible
Graphaea, or oyster-like animal. However, this shell has two ‘wing’ projections
out the side where all the descriptions of Graphaea do not show these. Perhaps it's a pearl oyster instead - Dr Retallak at the U of Oregon gave this suggestion - Your bivalve is not Gryphaea, but more like Pteroperna cf. P. plana (a common species in the Pliensbachian Robertson Formation)
We are starting to work out this thin blade of bone. Further work (see the next entry) shows this is a very complete scapula. The notches on the edge are from some bone that broke off with the covering rock, which came away in one piece. We have them & will re-glue them back on. Number one rule in Paleontology - KEEP ALL THE PIECES!!!!!
Further work (see next post) suggests this may be part of the skull -
Last, we have a great Nautiloid starting to be removed. It’s
over 11 cm in diameter, and one side is apparently uncrushed. It’s going to be
beautiful:
It’s hard to get a full picture as it’s very close to one of
the shoulder girdle bones shown above This block contains three other incomplete
Nautiloids, and part of another one that could be complete – the rest is in
another block. I still think the Nautiloids were eating Bernie’s carcass when
they were all buried – this may explain why we have so many in one small spot.
More to come……..
super!
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