Incremental lines of von Ebner in dinosaurs and the assessment of tooth replacement rates using growth line counts

AUTOR(ES)

Erickson, G. M.

FONTE

The National Academy of Sciences of the USA

RESUMO

Dinosaur dentine exhibits growth lines that are tens of micrometers in width. These laminations are homologous to incremental lines of von Ebner found in extant mammal and crocodilian teeth (i.e., those of amniotes). The lines likely reflect daily dentine formation, and they were used to infer tooth development and replacement rates. In general, dinosaur tooth formation rates negatively correlated with tooth size. Theropod tooth replacement rates negatively correlated with tooth size, which was due to limitations in the dentine formation rates of their odontoblasts. Derived ceratopsian and hadrosaurian dinosaurs retained relatively rapid tooth replacement rates through ontogeny. The evolution of dental batteries in hadrosaurs and ceratopsians can be explained by dentine formation constraints and rapid tooth wear. In combination with counts of shed dinosaur teeth, tooth replacement rate data can be used to assess population demographics of Mesozoic ecosystems. Finally, it is of historic importance to note that Richard Owen appears to have been the first to observe incremental lines of von Ebner in dinosaurs more than 150 years ago.

Documentos Relacionados

• On the relationship between tetracycline and the incremental lines in dentine.
• Growth rates of Actinomyces viscosus and Streptococcus mutans during early colonization of tooth surfaces in gnotobiotic rats.
• Growth Rates of Actinomyces viscosus and Streptococcus mutans During Early Colonization of Tooth Surfaces in Gnotobiotic Rats
• The time scale of tooth development and replacement in Xenopus laevis (Daudin).
• Assessment of Tooth Structure using an Alternative Electrical Bioimpedance Spectroscopy Method