Fossil teeth reveal some dinos were fussy eaters

Some dinosaurs were picky eaters. Certain plant-munching dinosaurs preferred circumstantial parts of plants, caller information show.  

Researchers person agelong thought that what these herbivorous dinos ate was based connected their height. But a caller survey challenges that. Chemical clues successful 150-million-year-old teeth suggest they alternatively selected nutrient based connected its nutrients and texture.

“Herbivores had antithetic diets,” says paleontologist Liam Norris. He works astatine the Texas Science & Natural History Museum successful Austin. “If they are eating softer parts similar leaves, versus eating twigs oregon possibly bark, that looks similar it is much significant” than a species’ size.

His squad studied dinosaur bony enamel. This is the hard outer worldly connected teeth. The researchers focused connected its calcium isotopes. (These are forms of an constituent that person antithetic numbers of neutrons.) Certain isotopes correspond to what the dinos had eaten. A wider scope of calcium-isotope levels points to a much varied diet. 

Norris and his radical figured retired a works eater’s favourite foods by comparing the dinos’ tooth-isotope levels to those of modern herbivores.

The towering Camarasaurus lived successful the Late Jurassic period. That was betwixt immoderate 164 cardinal to 145 cardinal years ago. Researchers had thought this long-necked dino mostly ate leaves from treetops. It surely could person reached these somewhat brushed bits. But it ate rougher worldly — woody plants and twigs, the survey present concludes.

Meanwhile, the smaller, beaked Camptosaurus preferred softer works parts, specified arsenic leaves and buds. These and different herbivores mightiness person been capable to coexist due to the fact that they ate antithetic foods.

Calcium clues

“People person been looking astatine dinosaur teeth for galore decades,” says dinosaur adept Paul Barrett. He didn’t instrumentality portion successful the caller survey but works astatine the Natural History Museum successful London, England. “This is simply a nice, caller method for looking astatine the aforesaid benignant of problem,” helium says. Calcium isotopes, helium adds, could assistance wherever fewer information beryllium connected a dino’s diet.

Norris’ squad besides measured calcium-isotope levels successful the teeth of 2 carnivores, oregon meat-eaters. The information suggest the crocodile-like Eutretauranosuchus ate mostly fish. The fierce Allosaurus, in contrast, dined mostly connected the soma of different dinosaurs. But Allosaurus didn’t munch overmuch connected bones, arsenic Tyrannosaurus rex did. Both T. rex and Allosaurus are theropods that stood connected 2 legs.

Norris’ squad shared its findings successful the Oct. 1 Palaeogeography, Palaeoclimatology, Palaeoecology.

Researchers had agelong looked astatine calcium isotopes successful bony enamel for hints astatine what immoderate carnal ate. But this is 1 of the archetypal times the method has been utilized connected precise aged dinosaur teeth, says Michael Benton. A paleontologist, helium works astatine the University of Bristol successful England.

“I deliberation this is an innovative method,” helium says of the caller work. It’s hard to bash it well, helium adds. But it confirms that chemic signs of fare instrumentality astir for a precise agelong time.