Mesozoic Era
The age of dinosaurs.
Triassic Period
The first mammals, dinosaurs, crocodiles, and turtles all appeared in the Triassic Period. Most of the sinapsids or mammal-like reptiles became extinct, along with ninety percent of life on earth, in the preceding Permian period at the close of the Paleozoic Era. Therefore this was a time of replenishment of life. Many strange and wonderful creatures inhabited the Triassic landscape. What was to become the state of New Mexico 215 million years later, was then a lush environment with numerous rivers and lakes. Crocodile-like reptiles called phytosaurs occupied an ecosystem that also contained bizarre armored herbivorous reptiles termed aetosaurs, metoposaurs (large headed amphibians), a large carnivorous thecodont called Postosuchus, the small dinosaur Coelophysis, the small enigmatic armored reptile called Vancleavea, several types of fish including a lungfish, a freshwater pelecypod named Unio, many ferns, conifers, and cycads. New Mexico is well known for its Triassic rocks and the important fossil assemblages they contain.
Phytosaur
Jurassic Period
Dinosaurs known from the Morrison Formation in New Mexico include: Camarasaurus, the families Diplodocidae including Diplodocus, Allosauridae including Allosaurus, Stegosaurus, Apatosaurus, Camptosaurus, Seismosaurus, Theropoda, Sauropoda, and Ornithopoda (Foster, 2003, p. 79-80). Petrified wood, stromatolites and dinosaur bone fragments are known from the Morrison in east-central New Mexico. Dinosaur fossils collected from this area that have no member information include: sauropod caudal vertebrae and phalanx, ornithopod cervical vertebra, Allosaurus vertebrae, and a Stegosaurus vertebral centrum (Lucas et al., 1985, p. 235-236). In addition, a femur and two tibial fragments of a small theropod were collected from the Morrison in Quay County, New Mexico (Hunt and Lucas, 2006, p. 115-118). Stromatolites have been reported from the Morrison in the Dry Cimarron Valley in Union County (Neuhauser et al., 1987, p. 153-159).
Cretaceous Period
In the 1920s, the famous fossil hunter Charles Sternberg collected dinosaurs from the Fruitland and Kirtland formations in the San Juan basin. Pentaceratops, a ceratopsian dinosaur found only in New Mexico, was one of the many fossils collected from these formations by Sternberg. Other dinosaurs from New Mexico include Parasaurolophus, Kritosaurus, Alamosaurus, etc. Crocodile and turtle fossils are also abundant in the Fruitland and Kirtland formations. I discovered a new Pachycephalosaur and a new Tyrannosaur from these formations. I discuss these finds in a later chapter. Important new dinosaurs from an earlier age have been discovered in western New Mexico in the Moreno Hill Formation. Zuniceratops, a ceratopsian, is one of these dinosaurs. A few partial mosasaurs, seagoing, serpent-like reptiles, have been discovered in the state.
William Cobban discovered and named many new ammonites from New Mexico.
The age of dinosaurs.
Triassic Period
The first mammals, dinosaurs, crocodiles, and turtles all appeared in the Triassic Period. Most of the sinapsids or mammal-like reptiles became extinct, along with ninety percent of life on earth, in the preceding Permian period at the close of the Paleozoic Era. Therefore this was a time of replenishment of life. Many strange and wonderful creatures inhabited the Triassic landscape. What was to become the state of New Mexico 215 million years later, was then a lush environment with numerous rivers and lakes. Crocodile-like reptiles called phytosaurs occupied an ecosystem that also contained bizarre armored herbivorous reptiles termed aetosaurs, metoposaurs (large headed amphibians), a large carnivorous thecodont called Postosuchus, the small dinosaur Coelophysis, the small enigmatic armored reptile called Vancleavea, several types of fish including a lungfish, a freshwater pelecypod named Unio, many ferns, conifers, and cycads. New Mexico is well known for its Triassic rocks and the important fossil assemblages they contain.
Phytosaur
Jurassic Period
Dinosaurs known from the Morrison Formation in New Mexico include: Camarasaurus, the families Diplodocidae including Diplodocus, Allosauridae including Allosaurus, Stegosaurus, Apatosaurus, Camptosaurus, Seismosaurus, Theropoda, Sauropoda, and Ornithopoda (Foster, 2003, p. 79-80). Petrified wood, stromatolites and dinosaur bone fragments are known from the Morrison in east-central New Mexico. Dinosaur fossils collected from this area that have no member information include: sauropod caudal vertebrae and phalanx, ornithopod cervical vertebra, Allosaurus vertebrae, and a Stegosaurus vertebral centrum (Lucas et al., 1985, p. 235-236). In addition, a femur and two tibial fragments of a small theropod were collected from the Morrison in Quay County, New Mexico (Hunt and Lucas, 2006, p. 115-118). Stromatolites have been reported from the Morrison in the Dry Cimarron Valley in Union County (Neuhauser et al., 1987, p. 153-159).
Cretaceous Period
In the 1920s, the famous fossil hunter Charles Sternberg collected dinosaurs from the Fruitland and Kirtland formations in the San Juan basin. Pentaceratops, a ceratopsian dinosaur found only in New Mexico, was one of the many fossils collected from these formations by Sternberg. Other dinosaurs from New Mexico include Parasaurolophus, Kritosaurus, Alamosaurus, etc. Crocodile and turtle fossils are also abundant in the Fruitland and Kirtland formations. I discovered a new Pachycephalosaur and a new Tyrannosaur from these formations. I discuss these finds in a later chapter. Important new dinosaurs from an earlier age have been discovered in western New Mexico in the Moreno Hill Formation. Zuniceratops, a ceratopsian, is one of these dinosaurs. A few partial mosasaurs, seagoing, serpent-like reptiles, have been discovered in the state.
William Cobban discovered and named many new ammonites from New Mexico.
Spathites puercoensis
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