3 April 2014
Cribratina, an index fossil for the Albian age
Posted by Callan Bentley
These four slabs, collected at “Fossil Hill,” north of the Cristo Rey laccolith at the Chihuahua (Mexico) / Texas / New Mexico triple point, bear positively-weathering fossils of the benthic foraminiferid called Cribratina, an index fossil for the Albian age / stage:
My field notebook serves as an imperfect sense of scale.
Here’s the Albian in the context of the middle of the Cretaceous period of geologic time, from the International Commission on Stratigraphy’s geologic time scale:
Zooming in closer, you can see they are elongate, with multiple “bubble”-like body chambers:
I plan to image these specimens with our macro GigaPan rig soon, so that you can explore them on your own.
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.
