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All, My apologies up front to the vert paleo list for a non-vertebrate
posting. However, since these
pearls occur in association with vertebrate remains, and were collected while
screening for verts, I should be able to qualify J I am curious about the occurrence of pearls
in the fossil record. I have collected them from two Late Cretaceous
formations. They are fairly common in the Smoky Hill Chalk (late Coniacian),
although difficult to distinguish from the background of many thousands of
inoceramid fragments that litter the surface. Pictures are here: http://www.oceansofkansas.com/images2/PEARLS.jpg A close-up: http://www.oceansofkansas.com/images2/pearl.jpg They can get large (very rarely), including
this huge 5 cm by 4 cm by 2.5 cm hemispherical specimen: http://www.oceansofkansas.com/images2/bigpearl.jpg … that was actually large enough to
have it’s own oyster sprat attached briefly before being buried in the
mud. It’s now in the At the base of the Upper Cenomanian Lincoln
Limestone Member (Greenhorn Limestone Fm), we have also found smaller
inoceramid pearls, like these 4 and 5 mm specimens, in association with lots of
small shark teeth and other small vertebrate remains: http://www.oceansofkansas.com/images2/GHPEARL1.jpg Here’s a cross-sectional view of the
inside of the 5 mm fossil pearl: http://www.oceansofkansas.com/images2/GHPEARL5.jpg The most recent paper I have seen on the
subject is Brown, 1940. It was
written after George Sternberg donated 50+ pearls from the Brown, R. W., 1940. Fossil pearls from the Are these “fossils” observed in other
marine deposits? Regards, |
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