Sauropodomorpha (sawr-oh-POH-dah-more-fah) is the suborder of massive,
quadrupedal herbivores with extremely long necks and tails.
Sauropodomorpha can be divided further into prosauropods and sauropods.
Among the sauropods were the largest land animals ever known:
Seismosaurus, Diplodocus, Apatosaurus (popularly known as Brontosaurus),
and others. Only the modern blue whale is larger than these creatures; no
land animal comes close. And the recent discovery of Argentinasaurus, with
a vertabrae over six feet across, may mean that these dinosaurs were even
larger than the blue whale.
The long neck of sauropods gave them a very long view of danger
approaching; it also enabled them to feed from foliage that no other
herbivores could reach. In addition, some think that the sauropods, even
the largest, could sit back on their tails, raising their front legs off
the ground. This posture would have given them an even greater reach for
It is thought that sauropods did not chew their food. Although sauropods
had teeth, they were ill-suited for grinding; therefore, it is thought
that Sauropods swallowed small stones, or gastroliths, to grind the food
they swallowed. (Many modern birds, such as chickens, do the same.)
The ratio of the sauropods' brain capacity to their body size is
incredibly small: they may have been good at eating and watching for
predators, but they were not particularly intelligent. For that matter,
neither are modern herbivores. Predators seem to need and have greater
Dinosaur trackways suggest that sauropods lived and traveled in herds.
It was once thought that because of their massive bulk (200,000 pounds
(90,700 kg) for Seismosaurus) sauropods spent their lives immersed
in shallow lakes, so that the water could buoy up their bodies. This
idea has been discarded; it has been demonstrated that the pressure of
the water would have collapsed their lungs. Sauropods were land animals,
perfectly capable of supporting their weight on dry land.
While evidence suggests that theropods may have been warm-blooded, it
is harder to argue the same for sauropods. A warm-blooded creature of
200,000 pounds (90,700 kg) would have to eat incredible amounts of
food to maintain its metabolism, but if it were cold-blooded, its
nutritional requirements would be much less.
Sauropods may have been gigantothermic; that is, their bodies were huge
and could not lose heat from the surface of their bodies as fast as it
was produced inside.