Elephants must feed for 18 hours a day. Sauropods could be could be 10 times elephant-size, or more, so how did they find enough hours in the day to feed? The answer may surprise you. With their tiny skulls and tiny teeth, they were huge--and hugely efficient--eating machines.
For us, chewing is the first step in digestion. But sauropods had to get as much down their throats as possible, as fast as they could. They had no time to chew. Instead, they tore the tips off branches or stripped the leaves from trees with rakelike teeth. Then they swallowed the greens whole.
Like sauropods, large living herbivorous reptiles such as Galapagos tortoises eat plants without benefit of chewing. An inner "fermentation tank" in the gut holds food for up to 11 days, giving bacteria plenty of time to break food down and extract its energy. Experts think sauropods could have fermented much greater amounts of plant matter for up to two weeks.
A Tale of Two Skulls
These two skulls may look similar, but one is from a 13-ton (12,000 kg) sauropod, Diplodocus (dih-PLOD-uh-cus) and the other from a 1,000-pound (450 kg) horse (Equus caballus). Both have nipping teeth at the front of the snout but only the horse combines nipping teeth with robust cheek teeth. Operating those grinding teeth takes powerful muscles, which attach to its heavy jaw. By contrast, the lower jaw of the sauropod looks almost fragile.
The lightweight sauropod skull makes a long neck feasible. And long flexible necks allowed sauropods to reach vast amounts of plant matter without moving those huge bodies much. Scientists calculate that a relatively small increase in neck length produces a surprisingly large increase in how much area the animal can reach.