themselves was . Most were less than in volume. The least massive clast was and the most was , with most of them being toward the smaller end of that range. The clasts tended to be close to spherical in shape, although the largest specimens were also the most irregular. The largest gastroliths contributed the most to the total surface area of the set. Some gastroliths were so large and irregularly shaped that they may have been difficult to swallow. The gastroliths were mostly composed of chert, with some sandstone, siltstone, and quartzite clasts also included. Some of the chert clasts actually contained fossils. Since some of the most irregular gastroliths are also the largest, it is unlikely that they were ingested by accident. Cedarosaurus may have found irregular clasts to be attractive potential gastroliths or was not selective about shape. The clasts were generally of dull coloration, suggesting that color was not a major factor for the sauropod's decision making. The high surface area to volume ratio of the largest clasts suggests that the gastroliths may have broken down ingested plant material by grinding or crushing it. The sandstone clasts tended to be fragile and some broke in the process of collection. The sandstone gastroliths may have been rendered fragile after deposition by loss of cement caused by the external chemical environment. If the clasts had been that fragile while the animal was alive, they probably rolled and tumbled in the digestive tract. If they were more robust, they could have served as part of a ball-mill system. Footnotes References Tidwell, Virginia; Carpenter, Kenneth; Brooks, William (1999). "New sauropod from the Lower Cretaceous of Utah, USA". Oryctos 2: 21–37. Tidwell, V., Carpenter, K. & Meyer, S. (2001). "New Titanosauriform (Sauropoda) from the Poison Strip Member of the Cedar Mountain Formation (Lower Cretaceous), Utah". In: Mesozoic Vertebrate Life. D.H. Tanke & K. Carpenter (eds.). Indiana University Press. pp. 139–165. . External links Cedarosaurus at The Paleobiology Database Brachiosaurs Early Cretaceous dinosaurs of North America Fossil taxa described in 1999 Taxa named by Kenneth Carpenter Paleontology in Utah