Ancient reptile tooth enamal had varying degrees of thickness to shear and eat plants

A team of researchers from the United Kingdom, Australia and the U.S. found in a recent study that the teeth of some ancient reptiles had tooth enamel of varying thickness that likely helped shear plant material. One of the animals studied was Eilenodon, a plant-eating reptile from the Late Jurassic Period that has been found in Grand County as well as in Colorado. The study was published last week in the Journal of the Royal Society Interface.

Eilenodon would have looked similar to a large, beefy modern-day lizard, according to a press release from the Museum of Moab. It is related to the tuatara, a reptile only found today in New Zealand. The thickness of enamel (the hard shell on the outside of a tooth) can provide an insight into how a tooth formed and what kind of material an animal ate, according to the press release.

The U.S. portion of the research team included the Museum of Moab and the Denver Museum of Nature and Science. The team looked into the internal structure of Eilenodon teeth to find the relative thickness of the tooth materials. Paleontologist Marc Jones of The Natural History Museum in London led the team. “Studying teeth can tell us more about an animal’s diet, developmental history and relationship to other animals,” Jones said. “It was fascinating to be able to see inside this tooth and learn more about how its owner might have lived.”

Eilenodon had rows of closely packed teeth and a strong jaw for chewing and shredding plants. It probably would have eaten a range of plants, rushes and shrubs as well as the occasional insect.

Scientists used a neutron scanner to determine what Eilenodon teeth were made of and to make a 3-D map of the enamel inside the tooth. They found that the enamel inside the tooth was thick around the base to prevent fracturing, but thin at the tip to allow it to become sharp enough for shredding plant material such as horsetails and ferns. The enamel was thinner than its relative the tuatara, suggesting that these animals ate different foods.

The new article is available as a free PDF download at: http://rsif.royalsocietypublishing.org/content/15/143/20180039.