Ok. No more movie voice. But where did the large sauropod Camarasaurus roam? A new paper in Nature may be closer to discovering the truth.

Scientists believe that some dinosaurs migrated seasonally for food, and now Henry Fricke and his colleagues at Colorado College may have the evidence—thirty-two Camarasaurus teeth.

Camarasaurus were enormous. With an average length of 50 feet, they ate about twice as much as today’s modern elephants—almost 1,000 pounds of food each day! As Fricke told Nature News,

They are huge—they would probably have eaten themselves out of house and home if they stayed in one place.

According to the fossil record, Camarasaurus inhabited the dry plains of western North America. The teeth the researchers sampled were all found in Wyoming and Utah, where the ancient seasonality record is pretty clear. ScienceNOW explains:

During the wet season, the prehistoric lowland basins of Wyoming and eastern Utah were flat, open habitats carpeted with ferns and stands of conifers. The researchers propose that the dinosaurs left this area at some point during the year, probably during the dry season, when the smorgasbord of tasty plants closed.

How did the researchers extract the evidence of movement from the Camarasaurus teeth? By measuring the ratio of isotopes within the enamel, New Scientist explains.

The ratio of isotopes is determined by the water the dinosaurs drank. [Fricke] found the ratio in teeth was different to that in carbonate rock from the floodplain—which carries the signature of the water it formed in. This suggests that Camarasaurus sometimes left the area.

Fricke and his team suspect the dinosaurs headed to higher, wetter ground seasonally, when the plains were dry, possibly traveling up to 180 miles.

The team plans to sample the teeth of other dinosaur species next. They have a hunch that where the herbivores traveled, the carnivores were close behind.

Image credit: Dmitry Bogdanov/Wikipedia

The animals are built like carnivores, too. A genomic study on the wild panda in 2009 proved that that the bears have none of the features that other herbivores (like cows) have to breakdown the tough cellulose fibers of bamboo.

In fact, of the 12.5 kg (27.5 lbs) of bamboo the pandas eat in a day, they’re only able to digest about 17% of it. According to National Geographic News:

This explains why pandas also evolved a sluggish, energy-conserving lifestyle.

Scientists from the Chinese Academy of Sciences decided to look at the microorganisms that live in the guts of these bears. So they grabbed some panda poop, or, rather, stool samples from seven wild pandas and eight captive pandas. (Their diets vary a bit.)

Analyzing the samples, the researchers found 13 different types of Clostridium-related bacteria, known to breakdown cellulose. Of those, seven were unique to the pandas compared to other mammals. The researchers conclude that these microbes allow the panda to gain extra energy from the bamboo stalks.

Nature News describes this extraordinary feat in context:

These microbes are part of a suite of evolutionary adaptations — alongside powerful jaws and teeth, and pseudo-thumbs, bones that allow them to grip plant stalks — that help pandas to live on bamboo, despite having a carnivore’s digestive system.

The new research is published in this week’s Proceedings of the National Academy of Sciences.

Image: Mfield, Matthew Field/Wikipedia