FOSSIL CRINOID STEMS ('SCREWSTONE') - 300 million years old - Ukraine
« backSTEMS OF CRINOIDS (SEA LILIES)
('SCREWSTONE')
300 million years old
Donieck, Ukraine
This attractive and unusual form of fossil preservation is a result of the original fossil being dissolved by groundwater percolating through the rock leaving the original sediment-filled hole in the centre of the stem intact.
These fossils resemble screws although they do not have a helical thread. For this reason they were once known as 'screwstones'.
Click on a picture for a larger image
300 million years old
Donieck, Ukraine
This attractive and unusual form of fossil preservation is a result of the original fossil being dissolved by groundwater percolating through the rock leaving the original sediment-filled hole in the centre of the stem intact.
These fossils resemble screws although they do not have a helical thread. For this reason they were once known as 'screwstones'.
Click on a picture for a larger image
Size: 12 x 10 x 5 centimetres
Weight: 497 grams
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