When Dattilo (2004) described the trace fossils associated with eighteen vertically oriented and two convex-up specimens of Sowerbyella rugosa found on a single bed, he concentrated on the description and interpretation of the trace-fossil evidence. It was clear that these brachiopods had rotated through the sediments from a convex-up position to a commissure-up position. Dattilo (2004) proposed valve flapping as a potential mechanism by which Sowerbyella accomplished this re-orientation. He also argued that the ability to reorient themselves might have been shared by the concavo-convex strophomenides, and that this ability was not explained by the prevailing biomechanical models of strophomenide...

You do not currently have access to this article.