Here is a inexpensive fossil fish concretion form the Santana formation of Brasil. It is a nearly complete fossil fish concretion from an old collection. The fossil it self is quite poorly preserved. It is anyway a typical study piece.
Ceara, Araripe-basin, Brazil
Size of matrix:
about 185 x 115 mm
Lower Cretaceous, Santana Fm., Romualdo Member (about. 125 Mill. years)