Showing posts with label Tertiary. Show all posts
Showing posts with label Tertiary. Show all posts

Moeritherium, the ancestor of the elephant.


40 million years ago appeared on Earth the first elephants, rather the ancestors of the modern elephant. One of the ancestors called Moeritherium, which means "Moeris beast," which is an ancient lake in Egypt. Not only was the ancestor of modern elephants, was also the forerunner of the mammoth and mastodon, all Proboscidea (order of placental mammals). In addition it is also thought to be related to the manatee or sea cow or also known as Sirens.

The Moeritherium was small compared with an African elephant, the size of a big pig, a vegetarian-bodied, plump and heavy. He had thick legs, long, thin skull. Is believed to have had a rudimentary horn was somewhat flexible like a tapir or the Macrauchenia current. Instead their eyes and ears of the hippopotamus seemed to be placed in the top of the head perhaps for the amount of time remaining in the water of swamps and rivers. It is thought that the same ecological niche occupied in the hippo. But with them and speaking in evolutionary terms, they have nothing to do.



Macrauchenia ( Macrauchenia patachonica. )


The Macrauchenia is an extinct mammal with a body of a camel and a short trunk, reaching two and three meters long. (9.8 ft) with 1500 Kg of weight. Dwelt on the plains of South America in the Tertiary and Quaternary disappearing more than 8500 years ago. Despite having long-legged three-toed ungulate is unlikely to run at high speed due in part to the robust frame of body and hind legs that were shorter than the front. Age of herbivorous, eating in areas where I spent most of his time as swamps and grazing, provided him with his prehensile lip boot pastures. Its fur was short, similar to that of a modern horse. He had a trunk like they were today tapirs.
Contact with the men contributed to their extinction, as hunters have taken advantage of its low travel speed to kill and eat.

Gerrothorax


Gerrothorax is an extinct genus of amphibian temnospondyl who lived in the late Triassic period (about 210 million years ago) in what is now Germany and Greenland. Reached an approximate length of 1 meter. Their bodies are flattened, suggesting they were hiding under the sand or mud at the bottom of rivers and lakes as potential victims stalked her large eyes focused upward. The skull had a peculiar way with angular protrusions on both sides. This geometry of the skull is reminiscent of the genus Diplocaulus, but less developed.

Fossils show that the species of this genus were pedomórficas, keeping three pairs of gills also in the adult stage, which allowed them to breathe underwater. This feature also found in some current caudate, as in certain species of the family and Ambystomatidae Mudpuppy.


Curiosity: The lower jaw was fixed Gerrothorax and chewing had to raise his head and drop it. That is, exactly the opposite of what we do and almost all the animals of creation.

Hyracotherium

Hyracotherium (beast like a Hyrax), also known as Eohippus, is a genus of mammal Perissodactyla Palaeotheriidae family.

It is considered an ancestor of the horse, rhinoceros and tapir. It is a quadruped animal that lived in the Northern Hemisphere (Asia, Europe and North America) during the Eocene period, makes 60 to 45 million years. The line to the existing horse evolució through the following animals Preistorica: Oligohippus, Merichippus, Pliohippus. In chronological order.



Hyracotherium was a small herbivore the size of a fox, media cross about 35 inches and weighed 6 kg, had four toes on the forefeet and three on hind paws protected, the central one being longer. These animals were already clearly like the horse, despite its small size and probably lived in forests browsing. His teeth were adapted for the consumption of young leaves of the bushes and his eyes were different from modern horses as they were located more to the center of the head preventing a good side vision (which in the modern horse serves as defensive system), Eohippus but did not need because in the jungle environment in which they lived, was more effective camouflage to avoid predators.

Glyptodon



The glyptodon, always connected with existing armadillos, a native of America. The glyptodon measured about 3 m and weighed about 1.4 t, being equivalent in size and shape to a Volkswagen Beetle. It was a herbivore and, by its constitution, it is assumed that it was not very agile. His defense against predators was based on its rigid shell. Different species are distinguished by different types of shells. Many of these shells remained empty throughout the plains of Uruguay and Argentina will likely serve as a refuge for early humans in the region.

The glyptodon is part of the group of placental mammals known as Xenarthra. This order of mammals includes armadillos, as well as several extinct species.

The glyptodon emerged in the Pliocene in South America, migrating north after, when the Isthmus of Panama joined the Americas. It is believed that they were hunted by human populations in their environment, to use the carcasses of dead animals as a refuge from hostile environments. Became extinct about 10,000 to 8,500 years.



The glyptodontes oldest known lived in the early Tertiary and were not very large. After appearing species were becoming larger, until in the Quaternary, when there were also megatherium, there were real giants who roamed in what is now Patagonia Argentina. They had a great half-shell shaped eggshell consists of many hexagonal shaped plates, round, etc.., He was locked below the animal's body with a sturdy skeleton, had a long tail, some species, finished off with barbed thick and compact.

Arsinoitherium, the cousin of the elephant.


When alive, it would have superficially resembled a rhinoceros, and have been about 1.8 metres (5.9 ft) tall at the shoulders, and 3 metres (9.8 ft) long. The most noticeable feature of Arsinoitherium was a pair of enormous knife-like horns with cores of solid bone that projected from above the nose, and a second pair of tiny, knob-like horns on top of the head, immediately behind the larger horns. The skeleton is robust but shows that it was descended from a cursorial ancestor, and that the beast may have been able to run if it had to, like a modern elephant or rhinoceros. Its limb bones also suggest that the columnar legs of the living animal were elephant-like (especially since they ended in five-toed feet), rather than rhinoceros-like. Arsinoitherium had a full complement of 44 teeth, which is the primitive state of placental mammalian dentition, suggesting that it was a selective browser. The large size and hefty build of Arsinoitherium would have rendered it largely immune to predation. However, creodonts may have preyed on the young or infirm.


Arsinoitherium is an extinct genus of paenungulate mammal related to elephants, and hyraxes (Embrithopoda). These species were rhinoceros-like herbivores that lived during the late Eocene and the early Oligocene, from 36 to 30 million years ago, in areas of tropical rainforest, and at the margin of swamps.
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