This image below is published on page 1135 in: G. Keller, T. Adatte, W. Stinnesbeck, D. Stuben, Z. Berner, U. Kramar, M. Harting: More evidence that the Chicxulub impact predates the K/T mass extinction, Meteoritics & Planetary Science 39 (2004) 1127-1144.

This image is the CORNERSTONE of Kellers hypothesis that the bright objects in the squares are
PLANKTONIC FORAMINIFERS.
We think that these objects are inorganic DOLOMITE CRYSTALS , as shown by the various imaging methods.

To settle this question, THIS very thin section should be subjected to the same SEM backscatter and Cl imaging methods as shown in these pages.

All our samples and thin sections from Yaxcopoil-1 are available for scrutiny and testing.