Sauropod teeth fossils (not to scale) showing the diversity of tooth shapes found at Lightning Ridge. The fossils have different colours since they’re all made out of opal. Timothy Frauenfelder
Original Published Date: 
Friday, October 30, 2020

Full article published on The Conversation.

PhD candidate, Timothy Frauenfelder, and ARC Discovery Early Career Researcher Award (DECRA) recipient, Dr Nicolas Campione, from the University of New England have been studying opalised dinosaur teeth to help paint a picture of the eating habits and lifestyles of the most enormous dinosaurs to ever roam the planet: sauropods.

The researchers examined 25 sauropod tooth fossils aged between 95-100 million years old. From these, they were able to identify five 'morphotypes', or tooth-shape categories. Several features of a tooth can define its morphotype, including its symmetry, the presence or absence of grooves, and wear patterns. The teeth were then compared with those from more completely studied sauropods, linking them with at least three distinct species that would have cohabited the area around what is now Lightning Ridge.

The researchers also studied the 'microwear' or assortments of small features found on teeth from tooth-to-food or tooth-to-tooth contact, which can be preserved in tooth fossils as scratches or pits visible on worn surfaces. The ratio of scratches to pits can indicate the grittiness, or smoothness, of a dinosaur’s diet. By analysing these marks, the researchers could see that one of the species had a higher proportion of scratches than pits, so it likely fed on soft vegetation between 1-10m above the ground. The other had a higher proportion of pits, which suggests it ate harder vegetation less than 1m above the ground.

This discovery suggests that the two species might have coexisted, eating different foods in the same area, and contributing to a fascinating diversity in the sauropods that once inhabited New South Wales.

 

Photo credit: 

Sauropod teeth fossils (not to scale) showing the diversity of tooth shapes found at Lightning Ridge. The fossils have different colours since they’re all made out of opal. Credit: Timothy Frauenfelder and the Australian Opal Centre.