Some Cretaceous-Tertiary marine faunal changes

Abstract
The progressive disappearance of ammonites and belemnites is described in some detail. The Tertiary range of some of the common Cretaceous echinoids is discussed. References are given for the planktonic foraminifera. It is concluded that the late-Cretaceous disappearances were not simultaneous, were preceded by geographical contraction, and cannot be explained catastrophically.