Experiments on the movement of shells by water

Abstract

Currents comparable to those found on ocean bottoms are competent to move brachiopod shells. If the shell is on a coarse bottom it may move without the bottom material shifting: if the bottom is fine, sand currents of equal force will result in burial of the shell in situ, through scouring of the sand. Ease of movement of a shell increases with sphericity, esp. when the shell is small. Orientation of movable shells is random cf. current direction, at least for for small samples.