Chinese fossil dealers have an unfortunate, though earned reputation
of taking great liberties in their preparation and sales of fossils.
Paint and putty, mixing bones and taking artistic liberty are
among the common practices. And these practices bridge the gap
from crude to quite sophisticated.
A positive/negative specimen is one of the best ways of authenticating
a fossil. This crayfish is absolutely untouched. It is preserved
in the typical fine-bedded mudstone of the Lingyuan Formation.
There has been no restoration or enhancement. Take careful note
of the superb preservation of the 1st and 2 nd antennae, claws
and carapace. The tail fan is tucked under, the right hand side
faint, though visible.
This crayfish has been preserved in an exceptional manner. This
is a bit complicated; I hope you understand my explanation. The
Astacus is a split pair, and very 2D, however, it looks to me like
the split runs right through the middle anterior to posterior.
As such, I think we are looking at a mix of the inside of the dorsal
view on one plate and the insides of the ventral on the other.
Astacus is a genus of crayfish found in Europe and western Asia,
comprising three extant and four extinct species.