Duck-billed dinosaurs, described as ‘walking pulp mills’, had an amazing capacity to chew tough and abrasive plants with grinding teeth more complex than those of cows, horses and other grazers.
Duck-bill dinosaurs, also known as hadrosaurids, were the dominant plant-eaters in what are now Europe, North America, and Asia during the Late Cretaceous age, about 85 million years ago.
With broad jaws bearing as many as 1,400 teeth, hadrosaurids were previously thought to have chewing surfaces similar to other reptiles, which have teeth composed of just two tissues – enamel, a hard hypermineralized material, and orthodentine, a soft bonelike tissue, reports the journal Science.
“We thought for a long time that there was more going on because you could just look at the surface of the tooth and see advanced topography, which suggests that there are many different tissues present,” said study author Mark Norell, chair of the American Museum of Natural History’s Division of Paleontology, according to an American Museum statement.
To investigate the dinosaurs’ dental structure and properties in depth, Norell worked with Gregory Erickson, biology professor at Florida State University, who led the study and a team of engineers on a series of novel experiments.
Erickson sectioned the fossilized teeth and made microscope slides from them. These revealed that hadrosaurids actually had six different types of dental tissues – four more than reptiles and two more than expert mammal grinders like horses, cows, and elephants.
Erickson, who describes hadrosaurid dinosaurs as ‘walking pulp mills’, said: “We were stunned to find that the mechanical properties of the teeth were preserved after 70 million years of fossilization.”
“If you put these teeth back into a living dinosaur they would function perfectly!”