Rastellum Bivalve Fossil Sea Shell Prehistoric Oyster Cretaceous Collection (6)

Bivalve Fossil Seashell mm 63 x 16  gr 37.7 Oyster Rastellum (Arctostrea) carinatum Lamellibranchs Pelecypods Prehistoric Molluscs Cretaceous Mesozoic Collecting Paleontology Museum.

Pleasant fossil find of Ostraeidae Shell from the upper Cretaceous, representative collectible sample of best quality, with appreciable well-preserved anterior and posterior details of the shape of the shell of both long curved valves and the massive ornamental ribs. No restored at all. Only a piece, as in photos.

This Oyster Upper Cretaceous, typical of the fossil beds of Madagascar, is characterized by the valves long and curved, with the massive ribs crossing the upper valve.
The slanted edges have been baptized "clam notched". The zig-zag of the rhyme between the two shells, when they were united, contributed to filter the coarse dirt and debris that could enter inside the shell damaging the mollusk. How modern oysters, Rastellum (Arctostrea) carinatum lived in shallow coastal waters, including the intertidal zone (the area between the high and low tide) and fed with food particles filtered seawater.