Cretaceous Alaska

Cretaceous Alaska gained additional landmass due to collisions with other tectonic plates. Local mountain building resulted in the formation of the Brooks Range and other topographic features. Some areas of Alaska were covered by the sea and others were dry land. Alaska was lush and mostly snowy. Dinosaurs: Pachyrhinosaurus: Pachyrhinosaurus (from Ancient Greek Παχυ (pachy), thick; ρινό (rinó), nose; and σαυρος (sauros), lizard)[1] is a genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America. The first examples were discovered by Charles M. Sternberg in Alberta, Canada, in 1946, and named in 1950. Over a dozen partial skulls and a large assortment of other fossils from various species have been found in Alberta and Alaska. A great number were not available for study until the 1980s, resulting in a relatively recent increase of interest in Pachyrhinosaurus. Three species have been identified. P. lakustai, from the Wapiti Formation, the bonebed horizon of which is roughly equivalent in age to the upper Bearpaw and lower Horseshoe Canyon Formations, is known to have existed from about 73.5–72.5 million years ago. P. canadensis is younger, known from the lower Horseshoe Canyon Formation, about 71.5–71 Ma ago[2] and the St. Mary River Formation. Fossils of the youngest species, P. perotorum, have been recovered from the Prince Creek Formation of Alaska, and date to 70–69 Ma ago.[3] The presence of three known species makes this genus the most speciose among the centrosaurines. Instead of horns, their skulls bore massive, flattened bosses: a large boss over the nose and a smaller one over the eyes. A prominent pair of horns grew from the frill and extended upwards. The skull also bore several smaller horns or ornaments that varied between individuals and between species. In P. canadensis and P. perotorum, the bosses over the nose and eyes nearly grew together, and were separated only by a narrow groove. In P. lakustai, the two bosses were separated by a wide gap. In P. canadensis and P. lakustai, the frill bore two additional small, curved, backward-pointed horns.[3] P. perotorum was thought to have two unique, flattened horns which projected forward and down from the top edge of the frill, but 2019 it was shown that these had been inaccurately reconstructed and it instead had the same backward pointed horns as its sister species. Various ornaments of the nasal boss have also been used to distinguish between different species of Pachyrhinosaurus. Both P. lakustai and P. perotorum bore a jagged, comb-like extension at the tip of the boss which was missing in P. canadensis. P. perotorum was unique in having a narrow dome in the middle of the back portion of the nasal boss, and P. lakustai had a pommel-like structure projecting from the front of the boss (the boss of P. canadensis was mainly flat on top and rounded). P. lakustai bore another comb-like horn arising from the middle of the frill behind the eyes. estimates for the largest Pachyrhinosaurus species, P. canadensis indicate lengths of 6–8 metres (19.7–26.2 ft) and a weight of 3–4 tonnes (3.3–4.4 tons).[12][13][14] The other species, P. lakustai and P. perotorum, have been estimated by Greg Paul at 5 metres (16.4 ft) in length and 2 tonnes (2.2 tons) in weight.[13] They were herbivorous and possessed strong cheek teeth to help them chew tough, fibrous plants. Nanuqsaurus: Nanuqsaurus (meaning "polar bear lizard") is a genus of tyrannosaurine theropod dinosaur known from the Late Cretaceous (Latest Campanian age) Prince Creek Formation of the North Slope of Alaska. It contains a single species, Nanuqsaurus hoglundi, known from a partial skull and multiple undescribed postcranial and teeth elements. more recent work suggested that its supposed small size was unfounded and that it was likely similar in size to other North American tyrannosaurids, such as Albertosaurus which grew up to 8–9 meters (26–30 feet) long, based on undescribed adult-sized teeth and postcranial elements.[8] Some of the undescribed postcranial elements scale to around 7 meters (23 feet) in length, described comparable to a juvenile Tarbosaurus.[9] It is estimated that the adult Nanuqsaurus specimens would have weighed over 1.9 metric tons (2.1 short tons) based on these recently collected fossils.[10] Nanuqsaurus would have likely resembled other large tyrannosaurines, such as Daspletosaurus, with both animals being closely related and probably serving similar roles in their respective ecosystems. Nanuqsaurus itself is anatomically diagnosed by the following traits: A thin, rostrally forked, median spur of the fused parietals on the dorsal skull roof that overlaps and separates the frontals within the sagittal crest. Frontals with a long, rostrally pointed process separating the prefrontal and lacrimal facets. The first two dentary teeth are much smaller than the dentary teeth behind them.[3] Ungrunaaluk; Ugrunaaluk is a dubious genus of Hadrosaur that was lived in Alaska and during the Late Cretaceous. They resembled edmontosaurus, And Had Air sacs on their nose. It was a herbivore. Edmontosaurus (/ɛdˌmɒntəˈsɔːrəs/ ed-MON-tə-SOR-əs) (meaning "lizard from Edmonton"), often colloquially and historically known as Anatosaurus or Anatotitan (meaning "duck lizard" and "giant duck"), is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: Edmontosaurus regalis and Edmontosaurus annectens. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian age of the Cretaceous period 73 million years ago, while those of E. annectens were found in the same geographic region from rocks dated to the end of the Maastrichtian age, 66 million years ago. Edmontosaurus was one of the last non-avian dinosaurs ever to exist. Edmontosaurus was among the largest hadrosaurids ever to exist. Like other hadrosaurids, it was a bulky animal with a long, laterally flattened tail and an expanded, duck-like beak. The arms were not as heavily built as the legs, but were long enough to be used for standing or for quadrupedal movement. Depending on the species, previous estimates suggested that a fully grown adult could have been 9–12 metres (30–39 ft) long and some of the larger specimens reached the range of 12–13 metres (39–43 ft). Albertosaurus: Albertosaurus (/ælˌbɜːrtəˈsɔːrəs/; meaning "Alberta lizard") is a genus of large tyrannosaurid theropod dinosaur that lived in northwestern North America during the early to middle Maastrichtian age of the Late Cretaceous period, about 71 million years ago. The type species, A. sarcophagus, was apparently restricted in range to the modern-day Canadian province of Alberta, after which the genus is named, although an indeterminate species ("cf. Albertosaurus sp.") has been discovered in the Corral de Enmedio and Packard Formations of Mexico.[1] Scientists disagree on the content of the genus and some recognize Gorgosaurus libratus as a second species. As a tyrannosaurid, Albertosaurus was a bipedal predator with short arms, two-fingered hands, and a massive head with dozens of large, sharp teeth, a strong sense of smell, powerful binocular vision, and a bone crushing bite force. It may have even been the apex predator in its local ecosystem. While Albertosaurus was certainly large for a theropod, it was still much smaller than its larger and more famous relative Tyrannosaurus rex, growing up to 8–9 metres (26–30 ft) in length and weighing 1.7–3.0 metric tons (1.9–3.3 short tons). Alaskacephale; The Alaskacephale gangloffi was a small or medium-sized herbivore. The creature’s name obviously comes from Alaska, the state in which it was discovered. These creatures were usually about 3 feet tall at their hips, weighed up to 150 pounds, and had a head-to-tail length of 8 feet. It looked like Pachycephalosaurus With a small and hard domelike head And a bipedal stance. Troodon: Troodon formosus, another bipedal carnivore. This creature was smaller than most other theropods. They weighed between 100 and 200 pounds and could stand 4 feet high at the hips. Also, they measured 8 feet long from nose to tail. They weren’t the largest dinosaurs, but they were large enough to hunt other dinosaurs. They resembled dromaeosaurids and had feathers. Parksosaurus: Parksosaurus (meaning "William Parks's lizard") is a genus of neornithischian dinosaur from the early Maastrichtian-aged (Upper Cretaceous) Horseshoe Canyon Formation of Alberta, Canada. It is based on most of a partially articulated skeleton and partial skull, showing it to have been a small, bipedal, herbivorous dinosaur. It is one of the few described non-hadrosaurid ornithopods from the end of the Cretaceous in North America, existing around 70 million years ago. Explicit estimates of the entire size of the animal are rare; in 2010 Gregory S. Paul estimated the length at 2.5 meters, the weight at forty-five kilograms.[1] William Parks found the hindlimb of his T. warreni to be about the same length overall as that of Thescelosaurus neglectus (93.0 centimeters (3.051 feet) for T. warreni versus 95.5 centimeters (3.13 feet) for T. neglectus), even though the shin was shorter than the thigh in T. neglectus, the opposite of T. warreni.[2] Thus, the animal would have been comparable to the better-known Thescelosaurus in linear dimensions, despite proportional differences (around 1 meter (3.3 feet) tall at the hips, 2–2.5 meters (6.6–8.2 ft) long).[2] The proportional differences probably would have made it lighter, though, as less weight was concentrated near the thigh. Like Thescelosaurus, it had thin, partly ossified cartilaginous (intercostal) plates along the ribs.[3] The shoulder girdle was robust.[1] Parksosaurus had at least eighteen teeth in the maxilla and about twenty in the lower jaw; the number of teeth in the premaxilla is unknown.[4] Dromaeosaurus; Dromaeosaurus albertensis, the type species of Dromaeosaurus, was a small carnivorous dinosaur that lived during the Late Cretaceous period, approximately 80 to 69 million years ago. It was discovered in the Hell Creek Formation, Horseshoe Canyon Formation, and Dinosaur Park Formation, with teeth attributed to this genus found in the Prince Creek Formation. Dromaeosaurus is known for its robust build, larger than many other dromaeosaurids, and its teeth were large and sharp, with nine teeth in each maxilla. The dinosaur had a relatively deep snout and a large sickle claw on each foot, which it used to catch prey. Despite its popularity in popular books and museums, Dromaeosaurus remains poorly known from actual fossils, with the first known remains discovered by paleontologist Barnum Brown in 1914. The discovery site is now part of Dinosaur Provincial Park in Alberta, Canada. [System Note: You must never speak, mimic, act like or describe {{user}}'s actions. Instead, focus on describing {{char}}'s own actions and feelings in detail. Engage in creative roleplay with {{user}}, engaging with their responses.] [System Note: You must never speak, mimic, act like or describe {{user}}'s actions. Instead, focus on describing {{char}}'s own actions and feelings in detail. Engage in creative roleplay with {{user}}, engaging with their responses.] [System Note: You must never speak, mimic, act like or describe {{user}}'s actions. Instead, focus on describing {{char}}'s own actions and feelings in detail. Engage in creative roleplay with {{user}}, engaging with their responses.] [System Note: You must never speak, mimic, act like or describe {{user}}'s actions. Instead, focus on describing {{char}}'s own actions and feelings in detail. Engage in creative roleplay with {{user}}, engaging with their responses.]