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16.12.2015 19:26 - Encyclopedia Largest prehistoric animals Vol.1 Vertebrates part1 Mammals ch.5 Proboscideans walk around the world
Автор: valentint Категория: Забавление   
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Последна промяна: 02.05.2018 12:25


Genus † Sinomastodon
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Sinomastodon ("Chinese mastodont") is an extinct gomphothere genus (of order Proboscidea), from the Late Miocene to the Early Pleistocene deposits of south-east Asia (China, Japan, and Indonesia). It is not to be confused with the genus Mammut from a different proboscidean family, whose members are commonly called "mastodons".
The animal was very similar to modern elephants with size ranging from 3.6 to 5.3 m. Several species are known from China, the best known being S. hanjiangensis from the Late Miocene and Early Pliocene of the Shanxi province. It is known from an incomplete skeleton of an adult (measuring 5.3 m) including maxilla, mandibles, teeth, tusks and other materials have been discovered. The Japanese species S. sendaicus described in 1924 from dentary materials from Pliocene deposits has been ascribed to the genus, as well as the species S. bumiajuensis (formerly Tetralophodon) from the late Pliocene of Java. One individual of S. hanjiangensis was a 30 year-old 2.07 metres (6.8 ft) tall and weighed 2.1 tonnes (2.1 long tons; 2.3 short tons).

Genus †Eubelodon
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Eubelodon morrilli is an extinct genus of a North American proboscidean.This gomphothere had a trunk and tusks. It lived during the Miocene Epoch. It may have evolved from Platybelodon.

In some respects , it seems that Eubelodon is a primitive form of Tetrabelodon willistoni . Morrilli Eubelodon defenses are relatively large , but short , clearly wedge shaped , at the ends, without enamel bands . The pelvis , including the sacrum and sacral spine , was found perfectly preserved , and indicate that it was a large animal . The jaw is a surprising character: it is huge, straight and very long , with a rising lower jaw. Defenses measured four meters and a half beyond the jaw and lips.

Genus †Rhynchotherium
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Rhynchotherium is an extinct genus of proboscidea endemic to North America and Central America during the Miocene through Pliocene from 13.650—3.6 Ma, living for approximately 10 million years.
This gomphothere had two tusks and may have evolved from Gomphotherium.
Rhynchotherium was first described in 1868 on the basis of a lower jaw from the Miocene of
Tlaxcala, Mexico. Later, the type species epithet R. tlascalae was erected for the jaw by Henry Fairfield Osborn in 1918. In 1921, a gomphothere skull from the Mt. Eden area of southern California was described as a subspecies of Trilophodon shepardi (a now-defunct combination for Mastodon shepardi), T. s. edensis, but was subsequently reassigned to Rhynchotherium. Other species subsequently assigned to Rhynchotherium included R. falconeri, R. paredensis, R. browni and R. simpsoni.

 

Genus † Cuvieronius
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South American elephants (Cuvieronius) are extinct family Gomfoterii. External resembled modern elephants, except that the tusks were a little long and protruding, without significant bends the bone. South American elephants have disappeared at the end of the last ice age about 12,000 years. The exact cause of death of species is unknown, but it is believed that climate change has led to droughts, greater mortality among large animals in southeastern South America, probably in what is now Argentina, caused pandemics among giants have completely them destroyed along with other mammals, representatives of megafauna.
The South American elephant inhabited Central and South America. Fossils of this kind have been found in Argentina , Brazil, Bolivia , Colombia, Venezuela and others.
Sized South American elephants were roughly the same as modern African elephants. Their height was about four meters , a length of 6.5 meters and weighing about 8000 kg .
The species has spread in South America about 2.5 million. Years at the Inter-American largest exchange in which the Americas have connected a land area of ​​the Isthmus of Panama and so animals of North American species entering South America and vice versa. So many placental mammals entering South America.
Recently there has been speculation of some scientists that South American elephants are not totally disappeared and outnumbered population still lives in unexplored parts of the Amazon. These assumptions are based on the stories of local Indian tribes, but so far there is no evidence of this kind nowadays.

 

Genus † Stegomastodon
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Stegomastodon ("roof breast tooth") is an extinct genus of gomphothere, a family of proboscideans. It is not to be confused with the genus Mammut from a different proboscidean family, whose members are commonly called "mastodons", nor with the genus Stegodon, from yet another proboscidean subfamily, whose members are commonly called "stegodonts".
Stegomastodonts reached 2.8 meters in height ; weight is estimated at about 6 tonnes . Stegomastodon mirificus is known from NMNH 10707, a 30-year-old male known from most of a skeleton. It was 2.6 metres (8.5 ft) tall, with a weight around 4.7 tonnes (4.6 long tons; 5.2 short tons).
Like modern elephants, but unlike most of its closer relatives, it had just two tusks. These tusks curved upward and were about 3.5 metres (11.5 ft) long. Stegomastodon"s molars were covered in enamel and had a complex pattern of ridges and knobbly protrusions on them, giving the creature a large chewing surface that enabled it to eat grass. Its brain weighed about 11 pounds (5 kg).
It lived in North and South America. The two South American species arrived following the Great American Interchange. They were initially mixed feeders; S. waringi evolved toward grazing, while S. platensis evolved toward browsing. The Stegomastodon species occupied warmer, lower-altitude habitats east of the Andes, while the related gomphothere Cuvieronius hyodon occupied cooler, higher-altitude habitats. It has been C14 dated to 27,910 BP in the Chapala Lake region, Jalisco, Mexico, as of now its most recent presence in North America, with its latest occurrence as recently as 6,060 BP in Yumbo, Valle del Cauca, Colombia.

 
Superfamily Elephantoidea
                     
Genus †Tetralophodon

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Tetralophodon ("four-ridged tooth") is an extinct gomphothere genus belonging to the family
Gomphotheriidae.
Tetralophodon was an elephant-like animal which existed through the late Miocene to the Middle Pleistocene epochs approximately 10.9 million years.
Like typical gomphotheres, mastodons with four tusks, Tetralophodon had four tusks and a trunk. In fact, also this animal had two further tusks protruding from the jaw. The overall appearance recalled Gomphotherium, the best known genus of the family Gomphotheriidae.
Their body is believed to be about 2.58–3.45 m (8.5–11.3 ft) tall at the shoulder and up to 10 tonnes in weight larger than the size of the present Asian elephant, with the long trunk and incisors ranging up to 2 m (6.6 ft) long. These incisors are believed to be utilized as a defense mechanism
The large, four-cusped cheek teeth of these animals are approximately 60 mm (2.4 in) by 80 mm (3.1 in), about 6 times the size of a normal human tooth. These low-crowned, bunodont teeth are designed for crushing and grinding, compared with other mammals during this era that had sharp teeth used for cutting. The teeth of the tetralophodon indicate a diet of large fruits and vegetables. This diet is aided by the large size and long trunks of the elephantiods that enable these mammals to reach tall, fruit-bearing trees.
Some features, mainly concerning the teeth, would seem to place Tetralophodon close to the origin of today"s elephants. The molars, in particular, are more advanced and specialized than those of the other gomphotheres.
These animals were very widespread and successful proboscideans. Their fossils have been found from the late Miocene to the Middle Pleistocene epochs of Europe, Asia, and Africa. Most fossil records of tetralophodon are of four-ridged teeth. The North American species, T. campester and T. fricki, have been moved to the genus Pediolophodon in 2007. The majority of the gomphotheres became extinct at the end of the Pleistocene. While the reason for this extinction is still debated, what is known is that these massive elephantoids under the genus Tetralophodon did not survive.



Genus † Anancus
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Anancus is an extinct genus of gomphothere endemic to Africa,Europe, and Asia, that lived during the Turolian age of the late Miocene until the genus" extinction during the early Pleistocene, roughly from 3—1.5 million years ago.
Anancus stood around 3 metres (9.8 ft) tall, with a weight up to 5
tons, and closely resembled a modern elephant. It had two tusks, whereas most other gomphotheres had four. Aside from its somewhat shorter legs, Anancus was also different from modern elephants in that its tusks were much longer, up to 4 metres (13 ft) in length. The tusks were possibly defense weapons not unlike elephants of today.The molars were not composed of lamellae like those of true elephants, but had cusps, like tapir and pig molars; Anancus appears to have lived in forests, eating from trees and shrubs and digging out tubers and roots in the forest floor, and it died out when these forests gave way to grasslands. Although not as famous, Anancus was at least as big as its cousins the mammoths.

 

Family † Stegodontidae
                     Genus † Stegolophodon
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Stegolophodon is an extinct genus of proboscidean. Stegolophodon was a stegodontid with two tusks and a trunk. It lived during the Miocene, Pliocene and Pleistocene epochs and may have evolved into Stegodon. Fossils have been primarily found in Asia.He lived between the lower Miocene and Middle Pleistocene ( about 18 million years ago - 800,000 years ago ) and his remains were found in many parts of Asia but some have also been reported in Africa.
About 3 meters high and long over 5 generally stegolophodon was a large proboscideans . Some species , however, were much smaller ; a kind of early Miocene found in Japan was very small size (about one third of the continental forms ) .The appearance was to recall that of today"s elephants , mainly because of the fact that , unlike many proboscidean extinct , stegolophodon was virtually devoid of teeth in the jaw : the skull , although low, was very similar to that of elephants due to the presence the elongated upper fangs . In some species of this genus the lower tusks were extremely small , while others were completely absent.The mandible retained an elongated shape.
Stegolophodon would be a typical proboscidians Asia , where it developed from the end of the Miocene , about 18 million years ago . Stegolophodon is considered a baseline representative of stegodontidi , a group of proboscidean of the elephant -like appearance , which spread mainly in the Pliocene and Pleistocene in Asia with the kind Stegodon .

 

Genus † Stegodon
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Stegodon is a genus of the extinctsubfamily Stegodontinae of the order Proboscidea.It was assigned to the family Elephantidae (Abel, 1919), but has also been placed in Stegodontidae (R. L. Carroll, 1988). Stegodonts were present from 11.6 mya to late Pleistocene, with unconfirmed records of regional survival until 4,100 years ago. Fossils are found in Asian and African strata dating from the late Miocene. They lived in large parts of Asia, East and Central Africa and North America during the Pleistocene.
Stegodon was one of the largest proboscideans, along with more derived genera.S. zdansky is known from an old male (50+) from the Yellow River that is 3.87 metres (12.7 ft) tall and weighed approximately 12.7 tonnes (12.5 long tons; 14.0 short tons). It had a humerus 1.21 metres (4.0 ft) long, a femur 1.46 metres (4.8 ft) long, and a pelvis 2 metres (6.6 ft) wide.
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In the past, stegodonts were believed to be the
ancestors of the true elephants and mammoths, but it is currently believed that they have no modern descendants. Stegodon may be derived from Stegolophodon, an extinct genus known from the Miocene of Asia. Stegodon is considered to be a sister group of the mammoth, as well as the elephants. Some taxonomists consider the stegodonts a subfamily of Elephantidae. Both Stegolophodon and primitive elephants were derived from the Gomphotheriidae. The most important difference between Stegodon and (other) Elephantidae can be observed in the molars. Stegodont molars consist of a series of low, roof-shaped ridges, whereas in elephants each ridge has become a high-crowned plate. Furthermore, stegodont skeletons are more robust and compact than those of elephants.
In Bardia National Park in Nepal,there is a population of Indian elephants that, possibly due to
inbreeding, exhibit many Stegodon-like morphological features. Some dismiss these primitive features as recent mutations rather than atavisms.















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