Deinosuchus is an extinct genus related to the alligator that lived 73 to 80 million years ago, during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos (δεινός), "terrible", and soukhos (σοῦχος), "crocodile". The first remains were discovered in North Carolina (United States) in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.
Although Deinosuchus was far larger than any modern crocodile or alligator—measuring up to 12 m (39 ft) and weighing up to 8.5 metric tons (9.4 short tons)—in overall appearance it was fairly similar to its smaller relatives. It had large, robust teeth that were built for crushing, and its back was covered with thick hemispherical osteoderms. One study indicates that Deinosuchus may have lived for up to 50 years, growing at a rate similar to that of modern crocodilians, but maintaining this growth over a much longer period of time.
Deinosuchus fossils have been found in ten U.S. states, including Texas, Montana, and many along the East Coast. Fossils have also been found in northern Mexico. It lived on both sides of the Western Interior Seaway, and was an opportunistic apex predator in the coastal regions of eastern North America. Deinosuchus reached its largest size in its western habitat, but the eastern populations were far more abundant. Opinion remains divided as to whether these two populations represent separate species. Deinosuchus was probably capable of killing and eating large dinosaurs. It may have also fed upon sea turtles, fish, and other aquatic and terrestrial prey.
Description
Despite its large size, the overall appearance of Deinosuchus was not considerably different from that of modern crocodilians. It had an alligator-like broad snout, with a slightly bulbous tip. Each premaxilla contained four teeth, with the pair nearest to the tip of the snout being significantly smaller than the other two. Each maxilla (the main tooth-bearing bone in the upper jaw) contained 21 or 22 teeth. The tooth count for each dentary (tooth-bearing bone in the lower jaw) was at least 22. All the teeth were very thick and robust; those close to the rear of the jaws were short, rounded, and blunt. They appear to have been adapted for crushing, rather than piercing. When the mouth was closed, only the fourth tooth of the lower jaw would have been visible.
Modern American alligators, with the strongest bite of any living animal, have a maximum force of 9,452 newtons (2,125 lbf). The bite force of Deinosuchus has been estimated to exceed 18,000 newtons (4,000 lbf).[1] Even the largest and strongest theropod dinosaurs, such as Tyrannosaurus, probably had a bite force inferior to that of Deinosuchus.
Deinosuchus had a secondary bony palate, which would have permitted it to breathe through its nostrils while the rest of the head remained submerged underwater. The vertebrae were articulated in a procoelous manner, meaning that they had a concave hollow on the front end and a convex bulge on the rear; these would have fit together to produce a ball and socket joint.[7][8] The secondary palate and procoelous vertebrae are advanced features also found in modern eusuchian crocodilians.
The osteoderms (scutes) covering the back of Deinosuchus were unusually large, heavy, and deeply pitted; some were of a roughly semispherical shape. Deep pits and grooves on these osteoderms served as attachment points for connective tissues. Together, the osteoderms and connective tissues would have served as load-bearing reinforcement to support the massive body of Deinosuchus out of water. Consequently, despite its bulk, Deinosuchus was probably almost as agile on land as its modern relatives.
Although there is some disagreement as to its exact size, the fossil remains are nonetheless sufficient to indicate that Deinosuchus was substantially larger than any modern crocodilian. Even the relatively low estimate provided by Erickson and Brochu suggests that the maximum weight reached by Deinosuchus exceeded that of currently living species by a factor of three to five. Deinosuchus has often been described as the largest crocodilian of all time, but some other crocodyliforms—including Purussaurus, Rhamphosuchus, and Sarcosuchus—may have equaled or exceeded it in size.
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