Teeth hold clues to dinosaur migrations

Fig 1.- A migrating herd of Camarasaurus. 

The teeth shape and wear pattern could already tell a lot about the diet of long gone creatures. New scientific methods applied to fossil teeth allow deciphering even more subtle behavioral habits. Last year, oxygen isotope analysis performed on Spinosaurus teeth has already shown that the popular back-sailed theropod dinosaur had a semiaquatic lifestyle. More recently, a detailed distribution analysis of ¹³C and ¹⁸O isotopes in the teeth of several sauropod dinosaurs was used to measure their body temperature. Now, in a new paper by Henry C. Fricke, Justin Hencecroth and Marie E. Hoerner published in the journal Nature, variations in the ¹⁸O isotope content measured in the teeth of the common Morrison formation sauropod Camarasaurus, lead strong support to the migratory behavior of those dinosaurs. The ratio of isotopes varies with the water the dinosaur drank and is recorded in the teeth enamel. Water from low elevation wetlands have higher ratio of ¹⁸O than those coming from surface water and precipitations at higher altitude. Comparisons of the teeth isotope ratio with those of ancient soils and their variations show that Camarasaurus was seasonally migrating for food, traveling as much as several hundreds of kilometers. During the wet months, they were staying in the lowland basin, but during the dry seasons when drought was quite possible, they moved uplands in search of vegetation. Pretty neat…

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com)


References:

Amiot, R., Buffetaut, E., Lecuyer, C., Wang, X., Boudad, L., Ding, Z., Fourel, F., Hutt, S., Martineau, F., Medeiros, M., Mo, J., Simon, L., Suteethorn, V., Sweetman, S., Tong, H., Zhang, F., & Zhou, Z. (2010). Oxygen isotope evidence for semi-aquatic habits among spinosaurid theropods Geology, 38 (2), 139-142

Robert A. Eagle, Thomas Tütken, Taylor S. Martin, Aradhna K. Tripati, Henry C. Fricke, Melissa Connely, Richard L. Cifelli, and John M. Eiler, 2011, “Dinosaur Body Temperatures Determined from Isotopic (13C-18O) Ordering in Fossil Biominerals” Science. 333(6041):443-5.

H. C. Fricke, J.Hencecroth, M.E. Hoerner. 2011. Lowland–upland migration of sauropod dinosaurs during the Late Jurassic epoch. Nature. Advanced online publication.