6.6cm Fossilised Bivalve, Jurassic from Southern Madagascar
This 6.6cm Fossilised Bivalve is beautifully smooth and is a superb example from Southern Madagascar. This is a country famous for its remarkable variety of superb fossils and also its minerals. This bivalve is from Morondova which is in the Southern part of the island. It dates back to the Jurassic period and is approximately 150 million years old. This Fossilised Bivalve has been highly polished, to leave a beautifully tactile, and a gorgeous creamy coloured shell.
Bivalves are freshwater molluscs that have existed for over 500 million years. The actual name bivalve comes from the latin word ‘bis‘ and ‘valvae‘ meaning ‘two leaves of a door’. Remarkably after 500 million years these creature that still exists today. This is a huge family including scollops, mussels oysters and clams. Most of them are ‘filter feeders’ that bury themselves in the sediment or sand. Their shell consists of two hinged sections that open and close, allowing water to enter and then be fed through. They then feed on the tiny organisms, such as plankton as they filter the water. Altogether there are nearly 10,000 different species, living in both salt water, and also fresh water. The vast majority however are ones that live in salt or brackish water.