The sauropods were the largest of all dinosaurs, and some attained a
length of 85 feet and probably weighed 40 to 50 tons (_Brontosaurus_,
Pl. 44). They were primarily herbivorous dinosaurs which had become
adapted to an aquatic or semi-aquatic type of existence and probably
inhabited lakes, rivers, and swamps. The tracks of sauropod dinosaurs
have been collected from Lower Cretaceous rocks in central Texas (Pl. 4)
and Upper Cretaceous beds in Big Bend National Park in Trans-Pecos
Texas.