oth in Florida did not behave the same as one in New York, Wyoming, California, Mexico or Ohio."
THE WISDOM IN TEETH
For their research, Crowley and Baumann looked to the wisdom in teeth specifically museum specimens of molars from four mastodons and eight mammoths from Southwestern Ohio and Northwestern Kentucky. Much can be revealed by carefully drilling a tooth's surface and analyzing the stable carbon, oxygen and strontium isotopic signatures in the powdered enamel.
Each element tells a different story. Carbon provides insight into an animal's diet, oxygen relates to overall climatic conditions of an animal's environment and strontium indicates how much an animal may have traveled at the time its tooth was forming.
"Strontium reflects the bedrock geology of a location," Crowley says. "So if a local animal grows its tooth and mineralizes it locally and dies locally, the strontium isotope ratio in its tooth will reflect the place where it lived and died. If an animal grows its tooth in one place and then moves elsewhere, the strontium in its tooth is going to reflect where it came from, not where it died."
Their analysis allowed them to determine several things:
- Mammoths ate more grasses and sedges than mastodons, which favored leaves from trees or shrubs.
- Strontium from all of the animals (except one mastodon) matched local water samples, meaning they likely were less mobile and migratory than previously thought.
- Differences in strontium and carbon between mammoths and mastodons suggest they didn't inhabit the same localities.
- Mammoths preferred to be closer to the retreating ice sheet where grasses were more abundant, whereas mastodons fed farther from the ice sheet in more forested habitat.
"As a geologist, questioning the past is one of the most interesting and exciting things to do," says Baumann, an environmental geologist with a coPage: 1 2 3 Related biology news :1
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