A study shows thatthe dentition of hadrosaurs evolved the same as that of mammals, such as the mink or the elephant, which facilitated their adaptation to the flora of the environment and theirrapid expansion. According to the authors, “these bipeds broke with the primitive archetype of reptiles and developed one of the most sophisticated dentures ever discovered.” “When we analyzed the fossil remains we realized that the biting surfaces of their teeth were like those ofhorses, animals whose teeth are among the most sophisticated“, explains Gregory M. Erickson, co-author of the study published this week in the journal to the SINC agency.Science.
Previous research had championed the simplicity of hadrosaurs’ tooth structure. Its authors described their dental tissue equal to that of primitive reptiles – such as saurians – consisting of enamel and orthodentine, a soft tissue similar to bone. Faced with these theories, scientists have now shown that the dentition of these bipeds was very similar to that of mammals and was made up of six main tissues. “The teeth of these herbivores included all the constituents typical of mammalian grinding: enamel, orthodentin, secondary dentin and coronal cementum. This would have made them one of the species of animals with the most complex teeth”, collects the new work .
For the study, the remains of an Edmontosaurus from the American Museum of Natural History were used, analyzed with three-dimensional simulation techniques, in order to characterize the composition of the dental tissue, the morphology and the mechanics of the bite surface of the hadrosaurs.
Specialized teeth
Another central part of the research was the evolution of their dentition to find out why the hadrosaur teeth differed from that of reptiles – which was based on teeth made up of two tissues: enamel and dentin. The rows above and below the teeth of reptiles, unlike hadrosaurs, do not come into contact when they bite.
According to the work, primitivelyhadrosaurs had a dual-function dental system -based on slicing and grinding- essential to consume fibers and rigid plants. This dual model helped them pulverize those vegetables, release their nutrients and exploit the natural resources offered by the environment.
From there, not all hadrosaurs evolved in the same way. In some cases, the teeth developed into thick bite pavements around the chewing area, “probably to process the stiffer plant matter,” the study notes. Other individuals, on the other hand, lost the ability to grind food and their teeth specialized in cutting it into angular slices.
