However, these rivers have a sandy bottom, and the sand can hold water.

然而，这些河流的底部是砂质的，沙子可以容纳水。

In life, Fortey says, most of them probably simply lay upon the surface of the sandy sediment, like soft, structureless and inanimate flatfish.

“在活，”福泰说，“它们大多数很可能就趴在砂质沉积物的表面，就像没有固定形状、毫、软绵绵的比目鱼那样。”