Post by poseidon on Jul 31, 2021 20:39:34 GMT -5
Ceratosaurus was a carnivorous theropod dinosaur in the Late Jurassic period. This genus was first described in 1884 by American paleontologist Othniel Charles Marsh based on a nearly complete skeleton discovered in Garden Park, Colorado, in rocks belonging to the Morrison Formation. The type species is Ceratosaurus nasicornis.
Ceratosaurus followed the body plan typical for large theropod dinosaurs. A biped, it moved on powerful hind legs, while its arms were reduced in size. Specimen USNM 4735, the first discovered skeleton and holotype of Ceratosaurus nasicornis, was an individual 5.3 m (17 ft) or 5.69 m (18.7 ft) in length according to separate sources.[2]:115[7] Whether this animal was fully grown is not clear.[20]:66 Othniel Charles Marsh, in 1884, suggested that this specimen weighed about half as much as the contemporary Allosaurus. In more recent accounts, this was revised to 418 kilograms (922 lb), 524 kg (1,155 lb), or 670 kg (1,480 lb). Three additional skeletons discovered in the latter half of the 20th century were substantially larger. The first of these, UMNH VP 5278, was informally estimated by James Madsen to have been around 8.8 m (29 ft) long, but was later estimated at 7 m (23 ft) in length.[28] Its weight was calculated at 980 kg (2,160 lb), 452 kg (996 lb), and 700 kg (1,540 lb) in separate works. The second skeleton, MWC 1, was somewhat smaller than UMNH VP 5278 and might have been 275 kg (606 lb) in weight. The third, yet undescribed, specimen BYUVP 12893 was claimed to be the largest yet discovered, although estimates have not been published.[14]:192 Another specimen (ML 352), discovered in Portugal in 2000, was estimated at 6 m (20 ft) in length and 600 kg (1,320 lb) in weight.
Nanuqsaurus (meaning "polar bear lizard") is a genus of carnivorous tyrannosaurid theropod known from the Late Cretaceous period (early Late Maastrichtian stage) Prince Creek Formation of the North Slope of Alaska, United States. It contains a single species, Nanuqsaurus hoglundi, known only from a partial skull.
Restoration of the head
In its initial description, Nanuqsaurus was estimated to have been about 5–6 meters (16–20 ft) long, about half the length of Tyrannosaurus rex.[1][2][3] Its weight has been estimated to be 500–900 kilograms (1100–2000 lbs).[1][3] This diminutive size was postulated by Fiorillo and Tykoski as being an adaptation to its high-latitude habitat. However, later studies suggested that its supposed small size was unfounded, and that it was likely similar in size to other North American tyrannosaurids such as Albertosaurus.
Nanuqsaurus bears a particularly shaped ridge on its head indicating the carnivore was related to Tyrannosaurus rex. The length of the reconstructed skull, based on the proportions of related animals, is 60–70 cm (24–28 in).
Ceratosaurus followed the body plan typical for large theropod dinosaurs. A biped, it moved on powerful hind legs, while its arms were reduced in size. Specimen USNM 4735, the first discovered skeleton and holotype of Ceratosaurus nasicornis, was an individual 5.3 m (17 ft) or 5.69 m (18.7 ft) in length according to separate sources.[2]:115[7] Whether this animal was fully grown is not clear.[20]:66 Othniel Charles Marsh, in 1884, suggested that this specimen weighed about half as much as the contemporary Allosaurus. In more recent accounts, this was revised to 418 kilograms (922 lb), 524 kg (1,155 lb), or 670 kg (1,480 lb). Three additional skeletons discovered in the latter half of the 20th century were substantially larger. The first of these, UMNH VP 5278, was informally estimated by James Madsen to have been around 8.8 m (29 ft) long, but was later estimated at 7 m (23 ft) in length.[28] Its weight was calculated at 980 kg (2,160 lb), 452 kg (996 lb), and 700 kg (1,540 lb) in separate works. The second skeleton, MWC 1, was somewhat smaller than UMNH VP 5278 and might have been 275 kg (606 lb) in weight. The third, yet undescribed, specimen BYUVP 12893 was claimed to be the largest yet discovered, although estimates have not been published.[14]:192 Another specimen (ML 352), discovered in Portugal in 2000, was estimated at 6 m (20 ft) in length and 600 kg (1,320 lb) in weight.
Nanuqsaurus (meaning "polar bear lizard") is a genus of carnivorous tyrannosaurid theropod known from the Late Cretaceous period (early Late Maastrichtian stage) Prince Creek Formation of the North Slope of Alaska, United States. It contains a single species, Nanuqsaurus hoglundi, known only from a partial skull.
Restoration of the head
In its initial description, Nanuqsaurus was estimated to have been about 5–6 meters (16–20 ft) long, about half the length of Tyrannosaurus rex.[1][2][3] Its weight has been estimated to be 500–900 kilograms (1100–2000 lbs).[1][3] This diminutive size was postulated by Fiorillo and Tykoski as being an adaptation to its high-latitude habitat. However, later studies suggested that its supposed small size was unfounded, and that it was likely similar in size to other North American tyrannosaurids such as Albertosaurus.
Nanuqsaurus bears a particularly shaped ridge on its head indicating the carnivore was related to Tyrannosaurus rex. The length of the reconstructed skull, based on the proportions of related animals, is 60–70 cm (24–28 in).