drrockclub: Articulated bivalve fossils Both shell halves are still closed and intact (articulated),
drrockclub: Articulated bivalve fossils Both shell halves are still closed and intact (articulated), it means that this animal died in this spot exactly (probably buried by a pile of sediment), preserved in its living position. Sedimentary processes or predators have not disturbed it since, and so it has been lying in these sediments for about 250 million years by now. South Coast, New South Wales, Australia -- source link