Post by poseidon on Aug 7, 2021 17:41:08 GMT -5
Spinosaurus - Spinosaurus Aegyptiacus
Spinosaurus (meaning "spine lizard") is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago.[2][3] This genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon. Another possible junior synonym is Oxalaia from the Alcântara Formation in Brazil. Spinosaurus is the largest of all known carnivorous animals, nearly as large as or even larger than other theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus. Estimates published in 2005, 2007, and 2008 suggested that it was between 12.6 to 18 meters (41 to 59 ft) in length and 7 to 20.9 metric tons (7.7 to 23.0 short tons) in weight.[4][5][6] New estimates published in 2014 and 2018, based on a more complete specimen, supported the earlier research, finding that Spinosaurus could reach lengths of 15 to 16 meters (49 to 52 ft).[7][8][9] The latest estimates suggest a weight of 6.4 to 7.5 metric tons (7.1 to 8.3 short tons).[8][9] The skull of Spinosaurus was long, low and narrow, similar to that of a modern crocodilian, and bore straight conical teeth with no serrations. It would have had large, robust forelimbs bearing three-fingered hands, with an enlarged claw on the first digit. The distinctive neural spines of Spinosaurus, which were long extensions of the vertebrae (or backbones), grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors[who?] have suggested that the spines were covered in fat and formed a hump. Spinosaurus's hip bones were reduced, and the legs were very short in proportion to the body. Its long and narrow tail was deepened by tall, thin neural spines and elongated chevrons, forming a flexible fin or paddle-like structure.
Purussaurus - Purussaurus Brasilensis
Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Colhuehuapian to the Montehermosan in the SALMA classification. It is known from skull material found in the Brazilian and Peruvian Amazon, Colombian Villavieja Formation, Panamanian Culebra Formation and the Urumaco and Socorro Formations of northern Venezuela. The skull length of the largest known individual of the type species, P. brasiliensis is 1,453 millimetres (57.2 in).[1] It has been estimated that P. brasiliensis reached about 10.3 metres (34 ft) in length, weighing about 5.16 metric tons (5.69 short tons).[1] Another estimate gave a larger size of 12.5 metres (41 ft) in length and 8.4 metric tons (9.3 short tons) in weight, with a mean daily food intake of 40.6 kilograms (90 lb).[2] However, these proportions have been met with a lot of scrutiny, and it is more likely that Purussaurus reached only 10.9 metres (36 ft) long and 5.6 metric tons (6.2 short tons).[3] As only skulls have been found, the actual length is not certain. Bite force has been estimated to be around 52,500 N (around 5.3 metric tons-force).[2] The large size and estimated strength of this animal appears to have allowed it to include a wide range of prey in its diet, making it an apex predator in its ecosystem. As an adult, it would have preyed upon large to very large vertebrates such as the xenarthrans and notoungulates present, with no real competition from sympatric, smaller, carnivores. Researchers have proposed that the large size of Purussaurus, though offering many advantages, may also have led to its vulnerability. The constantly changing environment on a large geological scale may have reduced its long-term survival, favoring smaller species more resilient to ecological shifts. In other words, it was over-specialised and couldn't survive when its habitat changed, unlike smaller related species of caiman. The teeth vary between the three species of Purussaurus, but are always around 50 mm (2 in) long and curve slightly backwards. They have small ridges along two of the edges which resemble those in ziphodonts. This indicates that Purussaurus hunted large vertebrates, as these ridges are used for puncturing and holding on to flesh. The teeth are slightly flattened at the top and are roughly conical, which means that they would have been unlikely to break on impact with a thick bone. Teeth at the anterior are taller and more pointed, whereas those at the posterior are lower and more rounded.
Spinosaurus (meaning "spine lizard") is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago.[2][3] This genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon. Another possible junior synonym is Oxalaia from the Alcântara Formation in Brazil. Spinosaurus is the largest of all known carnivorous animals, nearly as large as or even larger than other theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus. Estimates published in 2005, 2007, and 2008 suggested that it was between 12.6 to 18 meters (41 to 59 ft) in length and 7 to 20.9 metric tons (7.7 to 23.0 short tons) in weight.[4][5][6] New estimates published in 2014 and 2018, based on a more complete specimen, supported the earlier research, finding that Spinosaurus could reach lengths of 15 to 16 meters (49 to 52 ft).[7][8][9] The latest estimates suggest a weight of 6.4 to 7.5 metric tons (7.1 to 8.3 short tons).[8][9] The skull of Spinosaurus was long, low and narrow, similar to that of a modern crocodilian, and bore straight conical teeth with no serrations. It would have had large, robust forelimbs bearing three-fingered hands, with an enlarged claw on the first digit. The distinctive neural spines of Spinosaurus, which were long extensions of the vertebrae (or backbones), grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors[who?] have suggested that the spines were covered in fat and formed a hump. Spinosaurus's hip bones were reduced, and the legs were very short in proportion to the body. Its long and narrow tail was deepened by tall, thin neural spines and elongated chevrons, forming a flexible fin or paddle-like structure.
Purussaurus - Purussaurus Brasilensis
Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Colhuehuapian to the Montehermosan in the SALMA classification. It is known from skull material found in the Brazilian and Peruvian Amazon, Colombian Villavieja Formation, Panamanian Culebra Formation and the Urumaco and Socorro Formations of northern Venezuela. The skull length of the largest known individual of the type species, P. brasiliensis is 1,453 millimetres (57.2 in).[1] It has been estimated that P. brasiliensis reached about 10.3 metres (34 ft) in length, weighing about 5.16 metric tons (5.69 short tons).[1] Another estimate gave a larger size of 12.5 metres (41 ft) in length and 8.4 metric tons (9.3 short tons) in weight, with a mean daily food intake of 40.6 kilograms (90 lb).[2] However, these proportions have been met with a lot of scrutiny, and it is more likely that Purussaurus reached only 10.9 metres (36 ft) long and 5.6 metric tons (6.2 short tons).[3] As only skulls have been found, the actual length is not certain. Bite force has been estimated to be around 52,500 N (around 5.3 metric tons-force).[2] The large size and estimated strength of this animal appears to have allowed it to include a wide range of prey in its diet, making it an apex predator in its ecosystem. As an adult, it would have preyed upon large to very large vertebrates such as the xenarthrans and notoungulates present, with no real competition from sympatric, smaller, carnivores. Researchers have proposed that the large size of Purussaurus, though offering many advantages, may also have led to its vulnerability. The constantly changing environment on a large geological scale may have reduced its long-term survival, favoring smaller species more resilient to ecological shifts. In other words, it was over-specialised and couldn't survive when its habitat changed, unlike smaller related species of caiman. The teeth vary between the three species of Purussaurus, but are always around 50 mm (2 in) long and curve slightly backwards. They have small ridges along two of the edges which resemble those in ziphodonts. This indicates that Purussaurus hunted large vertebrates, as these ridges are used for puncturing and holding on to flesh. The teeth are slightly flattened at the top and are roughly conical, which means that they would have been unlikely to break on impact with a thick bone. Teeth at the anterior are taller and more pointed, whereas those at the posterior are lower and more rounded.