Key Earth Science Links
Mesozoic Era—Dinosaur ichnofossils
Coprolites (Fossil Dung, Feces)
The Paleobiological Implications of Herbivorous Dinosaur Coprolites…Why eat Wood? Chin, K., 2007, Palaios, v. 22.Technical paper that describes fossil dung from a Maiasaura (hadrosaur) nesting site in Cretaceous rocks of Montana. The dung contains woody conifer plant debris, and burrows of dung beetles. The paper discusses what these finds imply about the diet of these duck-billed dinosaurs.
Dung Beetles at Wikipedia.com
A Review of Vertebrate Coprolites of the Triassic. Hunt and others, 2007, New Mexico Museum of Natural History and Science. Technical paper (online pdf) that summarizes known occurrences of coprolites from the Triassic. Some readers may be interested to see how scientists name these fossils (some dung species named for famous scientists…there’s a legacy), and the types of information that is extracted from studying fossil dung.
Dinosaurs Dined on Grass. Piperno and Suez, 2005. Technical summary of a report published in Science that found grass phytoliths (microscopic remnants) in sauropod (titanosaur) dinosaur coprolites from the late Cretaceous of India (65-71 mya). This is the oldest evidence of grasses in the world. Previously, the oldest grass fossils had been from the Cenozoic. Hence, studying fossil dung is helping to unravel the evolution of one of the more common land plants on the planet today.
Gastroliths (stomach stones)
Gastroliths are stomach stones. Some modern birds and reptiles swallow stones during their lives that remain thin their stomachs and help the animals grind up tough food and therefore aid in digestion, or act as ballast, and therefore aid in swimming. Fossil gastroliths have been found with ancient reptiles, birds, and dinosaurs. Beware: There are more fake or misinterpreted dinosaur “gastroliths” than actual fossil stomach stones. The only way to prove that a polished or abraded stone is a true fossil stomach stone is to find it in the abdomen of a fossil animal, and then to show that similar stones are not found in the rock in which the fossil animal was found.
No Gastric Mill in Sauropod Dinosaurs… Wings, O., and Sanders, P.M., 2007, Proceedings of the Royal Society, Biological Sciences, v. 274 (1610). Technical research publication (as online pdf) that describes studies of modern Ostrich stomach stones and compares those stones to the gastroliths found in sauropod and theropod dinosaurs. The study found that the gastroliths from theropod skeletons are a closer match, suggesting that theropod dinosaurs had bird-like “gastric mills” in their stomachs, while sauropods may not have.
Gastroliths from the Coal Oil Canyon Plesiosaur (NJSM-15435). Mike Everhart, Oceans of Kansas. Description of a long-necked plesiosaur with stomach contents and gastroliths. Gastroliths are common in plesiosaurs and may have been ingested to help digestion, provide ballast, or they may simply be stones that were swallowed accidentally. Includes many photos.
Plesiosaur Stomach Contents and Gastroliths from the Pierre Shale…David Cicimmurri and Mike Everhart, 2001, Oceans of Kansas. Description of another long-necked plesiosaur with stomach contents and gastroliths. Gastroliths are common in plesiosaurs and may have been ingested to help digestion, provide ballast, or they may simply be stones that were swallowed accidentally. Includes many photos.