Discussion

REEs are consistently higher throughout the dentine and drop off sharply in the enamel. Metals are also much more common in the dentine rather than the enamel except for sodium, which is frequently higher in enamel than in dentine. Oddly, Thorium was frequently missing from the samples while Uranium was relatively common in all of them.

High peaks of Thorium, Iron, and Aluminum could all be found in cracks in the enamel. These were often accompanied by strong decreases in Phosphorus, however Calcium remained consistent through many of these cracks.

Dentine had much more consistent amounts of REEs than enamel, and these REEs follow trends along the growth axis of the tooth though trends were inconsistent across specimens. Cerium, the most common REE in my samples often mirrored the behaviors of other REEs like Neodymium and Lanthanum, and these trends could not be discerned in the enamel.

There were no consistent trends along the growth axis of the teeth in many of the organic elements. While I do not feel that these data will allow for much to be determined about the life history of the animals, changes in REEs could lead to greater understanding of Camarasaurus behavior. Relating to another aspect of my research, there are no immediately obvious trends in ^44/42Ca, though it would still be interesting to calculate the ratio of the two species.

Ultimately, this project shows that dentine consistently has higher concentration of REEs than enamel. Species indicative of diagenesis (such as Iron, Aluminum, Uranium and Thorium) are far more common in dentine than enamel, with the exception of Sodium. This lends further evidence that dentine is much more susceptible to diagenetic alteration, while enamel is much less likely to be diagenetically overprinted. In turn, this means that enamel can reliably be used for environmental reconstruction in Jurassic fossils.