Numbers of gastropods and bivalves in the three stratigraphic intervals investigated.

Owing to the fact that they were collected over a number of years and by different groups it was not possible to sample-standardise the general collections of gastropods and bivalves with any degree of accuracy. However, the neogastropod collections are better constrained and reasonably accurate estimates of numbers of individuals can be made for all species. Therefore it is possible to use rarefaction to at least partially sample-standardise for the fact that the three time bins are of unequal stratigraphic thickness and temporal duration. * represents values for rarefaction to 100 individuals, i.e. E(S100). Total numbers of neogstropods for the three time bins are: Maastrichtian = 344; Paleocene = 343; Early - Middle Eocene = 3483. Key: LBF = López de Bertodano Formation; SF = Sobral Formation; LMF = La Meseta Formation.Numbers of gastropods and bivalves in the three stratigraphic intervals investigated.