Wooster, Ohio — The igneous petrology team has a thorough and entertaining report about their activities in the Wooster geology labs this summer. It has encouraged the summer paleontologists (that would be me and Macy Conrad ’18) to give a progress report. Compared to the high-temperature geochemistry going on in the basement, we are decidedly low-tech upstairs in the Paleo Lab!
Above is our set of fossil oysters (Pycnodonte vesicularis) from the Campanian (Upper Cretaceous) of southwestern France we collected this summer. Each oyster has been cleaned, labeled, and given its own tray. We’ve examined each specimen in a preliminary way to sort out the prominent sclerobionts (hard-substrate dwellers, like encrusters and borings). So far we’ve determined which have bryozoans, serpulids, sabellids, foraminiferans and bivalves attached to them, and we’ve recorded the types of borings we see on each, which makes an impressive list: Entobia, Rogerella, Maeandropolydora, Gnathichnus, Radulichnus, Talpina, Belichnus, Oichnus, and maybe Podichnus.
The diverse encrusting bryozoans are the greatest challenge, and they will produce the most interesting and rich data for our paleoecological and evolutionary hypotheses. These fine creatures are difficult to identify, but we have one of the world’s greatest bryozoologists on our side: Paul Taylor of the Natural History Museum. He gave us a large computer file of scanning electron microscope (SEM) images of the most likely bryozoans we will encounter. We printed each of the 232 images as our “mugshots”. We have started with the uniserial and multiserial cyclostome bryozoans because they’re the easiest recognize. When we see one, we identify the specimen with a pink tag.
Here’s a tray of oysters from the Aubeterre Formation with the beginning of our colorful tagging. Laborious, detailed work, but already we see that the diversity of sclerobionts will generate some good stories.
Future updates will include some of our own photomicrographs!