The familiar duck-billed dinosaur was apparently the ultimate vegetarian of the Late Cretaceous. A recent study led by Gregory Erickson from Florida State University has revealed the enormous grinding power that duck-billed dino teeth harbored. Hydrosaurids, the scientific name for the 85-million-year-old duckbills, each had a huge set of 1,400 chomping teeth, similar to those of today’s horses.
Until recently, scientists believed hadrosaurids had only two layers of tooth tissue, the typical amount for both reptiles and dinosaurs. Erickson and his colleagues used a special technique known as nanoindentation, which uses a diamond-tipped probe to determine the surface topography and mechanical action of fossilized teeth. The scientists then used microscopic slides of the teeth to determine the properties of the various tooth tissues. Besides enamel and orthodentine, which make up classic reptile teeth, the research group found four other layers of tooth tissue, including secondary dentine, coronal cementum, giant tubules, and mantle dentine. Scientists surmise that the last two layers, which are the only two that mammals lack, probably acted as defense against abscess formation in the duckbill dinosaur’s mouth. Using similar techniques, the scientists hope to determine properties of the chompers of other extinct species, and hope that this study will act as a precedent for studying fossil teeth across the board.
Read on at Horsetalk.co.nz.
The study is published in the journal Science.
The complex tooth of a 85-million-year-old hydrosaurid or duck-billed dinosaur (image by Gregory M. Erickson, Florida State University).