Zachary Staab
Assoc. News Editor

The research of Dr. Dominique Didier, associate professor of biology at Millersville University, and his colleagues on the fossil remains of “whorl tooth shark” were published in Biology Letters On February 27, 2013. The article “Jaws for a Spiral Toothed Whorl: CT Images Reveal Novel Adaptation and Phylogeny in Fossil Helicoprion” provides new evidence on how this unusual creature used its teeth and reveals comparisons between the shark and ratfish.
The toothy beast, also known by the genus name Helicoprion, had a skeleton consisting mainly of cartilage and a large tooth whorl that resembled a circular saw blade. While the precise workings and placement of the tooth whorl are unknown, bizarre reconstructions of Helicoprion show the tooth whorl “at the top of the head, or emerging from the mouth, or on the tail fin,” said Didier. The research of Didier and his colleagues delivered the first realistic image of this mostly unknown creature.

This is a fossil remains of the Helicoprion, is a shark tooth whorl.
This is a fossil remains of the Helicoprion, is a shark tooth whorl.

“Our research has provided a three-dimensional reconstruction of the jaws with the tooth whorl in place so we can now see how the tooth whorl was positioned and how it might have functioned,” said Didier. The team of researchers also determined, after researching Helicoprion for over one year, that the whorl tooth creature is technically not a “shark.” Closer examination of the jaw anatomy showed that the Helicoprion, or whorl tooth shark, is more closely related to ratfishes (chimaeroid fish) and their relatives.
The Tree of Life Grants funded the revolutionary research that was published by Didier and his colleagues. The Tree of Life Grants encompass a group of projects sponsored by the National Science Foundation (NSF). The projects can include studies of the origins of land plants, uncovering information on terrestrial predators, research on fungi and parasitic worms, and the connection between dinosaurs and birds.
“Our Tree of Life Grant is focused on the Chondrichthyes (all sharks, skates, stingrays and ratfishes),” said Didier. “The grant itself is a 5-year, $2.8 million project.”
The research team consisted of Dr. Leif Tapanila and Jesse Pruitt from Idaho State University; Dr. Alan Pradel, American Museum of Natural History in New York, Dr. Cheryl Wilga, Jason Ramsay, Robert Schlader from the University of Rhode Island, and Didier from Millersville. Each member of the team played a quintessential role in conducting research, acquiring fossil remains, or publishing the findings of the project. Didier explained how he contributed to the project by connecting with professionals and “by supporting the CT scanning and making the necessary connections to have that done.”
“Any time faculty accomplishments are publicized it’s a reflection of the high caliber of faculty scholarship we have at Millersville,” said Didier. The research teams revolutionary findings were recently featured in the article “Phenomena: Laelaps” by National Geographic. Didier concluded that facility engage in a “wide range of scholarly activities,” that sometimes go unnoticed by the Millersville community.