These reptiles adapted themselves to the same type habitat that was
occupied by the phytosaurs, which preceded them. Crocodiles and
alligators were much larger and more abundant during Cretaceous and
Cenozoic time than they are today; the crocodiles first appeared in the
Cretaceous and the alligators in the Tertiary. The remains of both
crocodiles and alligators have been found in Texas, and one such
crocodile (_Phobosuchus_) represents the remains of the largest
crocodile yet discovered (Pl. 43). This specimen probably had an overall
length of 40 to 50 feet, and its massive skull was 6 feet long and
possessed exceptionally strong jaws. The remains of this great beast
were collected from exposures of Upper Cretaceous rocks along the Rio
Grande in Trans-Pecos Texas.