Post by DinosaurMichael on Aug 14, 2012 8:08:20 GMT -5
Deinosuchus - Deinosuchus rugosus
Deinosuchus ( /ˌdaɪnəˈsjuːkəs/ DY-nə-SEW-kəs) is an extinct genus related to the alligator that lived 73 to 80 Ma (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.
Dunkleosteus - Dunkleosteus terrelli
Dunkleosteus (From "(David) Dunkle" + osteus (ïóôåïò, Greek: bone)) is a genus of prehistoric fish, one of the largest arthrodire placoderms ever to have lived, existing during the Late Devonian period, about 380-360 million years ago. This hunter, measuring up to 10 metres (33 ft) and weighing 3.6 tonnes (4.0 short tons), was a hypercarnivorous apex predator. Few other placoderms, save, perhaps, its contemporary, Titanichthys, rivaled Dunkleosteus in size. Dunkleosteus is a member of the pachyosteomorph arthrodires, and is more specifically usually placed in the family Dinichthyidae, a family composed mostly of large, carnivorous arthrodires like Gorgonichthys. Placodermi first appeared in the Silurian, and the group became extinct during the transition from the Devonian to the Carboniferous, leaving no descendants. The class lasted barely 50 million years, in comparison to the 400 million year long history of sharks. Due to its heavily armoured nature, Dunkleosteus was likely a relatively slow, but powerful, swimmer. It is thought to have dwelled in diverse zones of inshore waters. Fossilization tends to have preserved only the especially armoured frontal sections of specimens, and thus it is uncertain what exactly the hind sections of this ancient fish were like. As such, the reconstructions of the hindquarters are often based on smaller arthrodires, such as Coccosteus, that had hind sections preserved. Instead of teeth, Dunkleosteus possessed two pairs of sharp bony plates which formed a beak-like structure. Morphological studies done on the "jaw bones" (inferognathals) of juvenile and adult Dunkleosteus suggest that Dunkleosteus went through a change in jaw morphology and diet as it aged. Juveniles had stiffer jaws more similar to Coccosteus, and appear to have fed on various soft-bodied aquatic animals. The jaws of adults were more flexible to hold struggling prey, and were well equipped to bite through the bony armor of hard-bodied animals like other placoderms.
Deinosuchus ( /ˌdaɪnəˈsjuːkəs/ DY-nə-SEW-kəs) is an extinct genus related to the alligator that lived 73 to 80 Ma (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.
Dunkleosteus - Dunkleosteus terrelli
Dunkleosteus (From "(David) Dunkle" + osteus (ïóôåïò, Greek: bone)) is a genus of prehistoric fish, one of the largest arthrodire placoderms ever to have lived, existing during the Late Devonian period, about 380-360 million years ago. This hunter, measuring up to 10 metres (33 ft) and weighing 3.6 tonnes (4.0 short tons), was a hypercarnivorous apex predator. Few other placoderms, save, perhaps, its contemporary, Titanichthys, rivaled Dunkleosteus in size. Dunkleosteus is a member of the pachyosteomorph arthrodires, and is more specifically usually placed in the family Dinichthyidae, a family composed mostly of large, carnivorous arthrodires like Gorgonichthys. Placodermi first appeared in the Silurian, and the group became extinct during the transition from the Devonian to the Carboniferous, leaving no descendants. The class lasted barely 50 million years, in comparison to the 400 million year long history of sharks. Due to its heavily armoured nature, Dunkleosteus was likely a relatively slow, but powerful, swimmer. It is thought to have dwelled in diverse zones of inshore waters. Fossilization tends to have preserved only the especially armoured frontal sections of specimens, and thus it is uncertain what exactly the hind sections of this ancient fish were like. As such, the reconstructions of the hindquarters are often based on smaller arthrodires, such as Coccosteus, that had hind sections preserved. Instead of teeth, Dunkleosteus possessed two pairs of sharp bony plates which formed a beak-like structure. Morphological studies done on the "jaw bones" (inferognathals) of juvenile and adult Dunkleosteus suggest that Dunkleosteus went through a change in jaw morphology and diet as it aged. Juveniles had stiffer jaws more similar to Coccosteus, and appear to have fed on various soft-bodied aquatic animals. The jaws of adults were more flexible to hold struggling prey, and were well equipped to bite through the bony armor of hard-bodied animals like other placoderms.
