Yelma digitata Stromatolites

Description: This is a younger (Lower Cambrian) stromatolite from the Arbuckle Mountains in Oklahoma. By the time this stromatolite formed, the cyanobacterial organisms and their stromatolitic reef system had already undergone a steep decline, and were becoming restricted to environments less favorable to other marine life with which they competed or from which they suffered predation.

This one derives its informal name from its namesake which comes from Australia.