Half of the Australia's Great Barier Reef Northern Coral Dead or Dying

Australian scientists said on Wednesday that just seven percent of the Great Barrier Reef, has been untouched by mass bleaching that is likely to destroy half of the northern coral. Bleaching occurs when the water is too warm, forcing coral to expel living algae and causing it to calcify and turn white. Mildly bleached coral can recover if the temperature drops, otherwise it may die.

 Although the impact has been exacerbated by one of the strongest El Nino weather systems in nearly 20 years, scientists believe climate change is the underlying cause.

The Great Barrier Reef stretches 2300km along Australia's North-East coast and is the world's largest living ecosystem. 

UNESCO's World Heritage Committee last May stopped short of placing the Great Barrier Reef on an in Danger list, but the ruling raised long-tern concerns about its future.

New Species of Extinct Rodent Found in Israel

A very little amount of tiny teeth found in Israel's Negev desert led an international tram of researchers to describe a new species of rodent which has been extinct for nearly 18 million years. The species named Sayimys negevensis.

This discovery sheds new light on the likely dispersal route of mammals and other species between Eurasia and Africa in the Early Miocene and highlights Israel's special paleogeographic position as the lynch-pin of the Levantine corridor connecting Eurassia with North Africa. This species also known as comb-rat. The name of the species comes from the its place of discovery. 

During the early Miocene Israel was still more firmly attached to Africa and most of the mammals found there were of African origin. Sayimys negevensis is one of the few species discovered in Israel with Eurasian affinities.

The discovery of the new rodent is part an international focusing on the Early Miocene fauna of Israel and its paleogeographic implications.

Newly Discovered Dinosaur Reveals How T.Rex Became King of the Cretaceous

The fossilized remains of a new horse-sized dinosaur reveal how Tyrannosaurus Rex and its close relatives became top predators, according to a new study published in the Proceedings of the National Academy of Sciences. 

Paleontologists have long known from the fossil record that the family of dinosaurs at the center of the study - tyrannosaurs - transitioned from small bodied species to fearsome giants like the T. rex over the course of 70 million years. But now newly discovered dinosaur fossils suggest that much of this transition and growth in size occurred suddenly, toward the end of this 70 million year period. The study also shows that before the evolution of their massive size, tyrannosaurs had developed keen senses and cognitive abilities, including the ability to hear low-frequency sounds. This positioned them to take advantage of opportunities to reach the top of their food chain in the Late Cretaceous Period after other groups of large meat-eating dinosaurs had gone extinct about 80 -90 million years ago.

Until now, little was known about how tyrannosaurs became the giant, intelligent predator that dominated the landscape about 70 to 80 million years ago. The newly discovered species, named Timurlengia euotica, lived about 90 million years ago and fills a 20 million year gap in the fossil record of tyrannosaurs. The new species is a tyrannosaur but not the ancestor of the T.rex. 

The species' skull was much smaller than  smaller than that of T.rex. However, key features of Timurlengia's skull reveal that its brian and senses were already highly developed. Timurlengia was about the size of a horse and could weigh uo to 600 pounds. It had long legs and was likely a fast runner. 

The first tyrannosaurs lived during the Jurassic Period, around 170 million yeras ago, and were only slightly larger than a human. However, by the Late Cretaceous Period - around 100 million years later -tyrannosaurs had evolved into animals like T. rex which could weigh up to 7 tons.

The new species' small size some 80 million  years after tyrannosaurs first appeared in the fossil record indicates that its huge size developed only toward the end of the group's long evolutionary history.

The new study was funded by the European Commision The fieldwork was supported by the Natioanal Science Foundation and the National Geographic Society. The work was carried out in collaboration with researcheers at the University of Edinburgh, Russian Academy of Sciences and Saint Petersburg State University.

First North American Monkey fossils are Found in Panama Canal excavation

Seven fossil teeth exposed by the Panama Canal expansion project are the first evidence of a monkey on the North American continent before the Isthmus of Panama connected it to South America 3.5 million years ago. A team including Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute (STRI), published this discovery online in the journal,Nature. They named the new monkey species Panamacebus transitus in honor of Panama and the monkey's movement across the ancient seaway that divided North and South America.

Before the monkey teeth were discovered, the evidence of movement of a mammals from South America are 8.5 - 9 million-year-old fossil remains of giant sloths. The authors of this report suggest two explanations: 

1. That mammal from South America were more adapted to life in the South American derived forests still found in Panama and Costa Rica than to other forest types characteristic of Northern Central America
2. That the lack of exposed fossils deposits throughout Central America means that evidence of these dispersals has yet to be revealed.

Evolution of Giant Bears in the Americas

During the Pleistocene giant bears weighing over 1000 kg roamed both North and South America. These giants belonged to a now practically extinct subfamily of bears - Tremarctinae - which is today only represeeinted by the small, herbivorous Andean spectacled bear (Tremarctos omatus).

The giant North American bears (Arctodus) and South American bears (Arctotherium) have long been believed to be each others' closest relative. However, by comparing ancient DNA data obtained from representatives of the two extinct genera and comparing them with the living species, the scientists were able to show that Arctotherium is most closely related to Tremarctos and not Arctodus. 

This convergent evolution would have arisen in response to similar environmental conditions on both continents, most like it an abundance of large herbivore carcasses(killed by smaller predators), which Arctodus and Arctotherium could effectively dominate, and a lack of competing scavengers.

Mammoths Meted Beyond Species Boundaries

A new study suggested that different species of mammoths meted in North America. A new research study on the DNA structure of the mammoth genome suggests that they meted beyond their species boundaries. Several species of mammoth are thought to have roamed across the North American physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring.

A species can be defined as a group of similar animals that can successfully breed and produce fertile offspring. By using differences in the size and shape of their fossilized teeth, a number of North American mammoth species have been identified. But some scientists are not confident this method of species categorization tells the whole story.

North American mammoths such as the Colombian mammoth and the Wooly Mammoths were historically thought to originate from two separate primitive species. However, the latest DNA analysis agrees with a more recent idea that all North American mammoths originated from a single primitive species, the Steppe Mammoth. So, while mammoths clearly method of differences in their physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring. 

Despite this apparent adaptability, which should surely be a recipe for success, mammoths disappeared from the face of Earth 10,000 years ago. 

As well as challenging the classic method of defining a species, scientists believe the findings of this study are just the start of understanding mammoth evolutionary history. Techniques to extract and analyses ancient DNA have undergone a tremendous improvement in recent years and as these technologies continue to improve we can expect further breakthroughs.

Diprotodon

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia 

Order: Diprotodontia

Family: Diprotodontidae

Genus: Diprotodon

Species: D. optatum

Diprotodon, meaning "two forward teeth" is the largest known marsupial ever to have lived. Along with many other members of a group of unusual species collectively called the Australian megafauna, it existed from approximately 1.6 million years ago until extinction some 46,000 years ago.

The closest surviving relatives of Diprotodon are the wobats and the  koala. It is suggested that diprotodonts may have been an inspiration for the legends of the bunyip as some Aboriginal tribes identify identify Diprotodon bones as those of bunyips.

Description

Diprotodon superficially resembled a rhinoceros without a horn. Its feet turned inwards like a wombat's giving it a pigeon-toed appearance it had strong claws on the front feet and its pouch opening faced backward. Footprints of its feet have been found showing a covering of hair which indicates it had similar to a modern wombat. Until recently it was unknown how many species of Diprotodon had existed. Eight species are described although many researchers believed these actually represented only three at most while some estimated there could be around twenty in total.

Up to 3.8 , long (head tail) and 1.7 m at the shoulder.

Habitat

Diprotodon is known from many sites across Australia, including the Darling Downs in southeastern Queensland; Wellington Caves, Tambar Springs Cuddie Springs in New South Wales; Bacchus Marsh in Victria,; Diprotodon is not known from New Guinea, southwestern Western Australia, the Northern Territory oor Tasmania. Diprotodon preferred semi-arid plains, savannahs and open woodlands,and is generally absent from hilly, forested coastal regions. Diprotodon is known from some coastal localities, including Naracoorte Caves and Kangaroo Island in South Australia. However, these areas may have been  further from the coast in the Pleistocene when sea levels were lower.

Australian Pleistocene habitats changed over time in response to the changing climate. Dry, windy conditions alternatated with more equable conditions throughout this period and sea levels were generally much lower than today as ice was locked in polar regions. Extended droughts would have made much of inland Australia uninhabitable; hundreds of individuals have been found at the center of Lake Calabonna in northern South Australi, trapped in the mud as the lake bed dried  out. On the Darling Downs in Queensland, one study of Diprotodon habitat has found that areas once covered in woodlands, vine thickets and scrublands gave way to grasslands as the climate became drier.

Evolution

It is unlikely that Diprotodon moved in large herds, as sometimes depicted. Marsupials are not known to form large groups. The large numbers of individuals found at Lake Callabonna were probably smaller family groups drawn en masse to the drying waterhole. Diprotodontids first appear in the Oligocene, about 25 million years ago. These early diprotodontids were probably descended from late Oligocene to early Miocene to early Miocene wynyardiids and were about the size of sheep.

The subfamily Diprotodontinae, including Diprotodon optatum, are a Pliocene-Pleistocene group.  Diprotodon may have evolved from the Pliocene diprotodontine Euryzygoma during the late Pliocene. A recent study based on dentition has found that there is just a single variable species of Diprotodon, Diprotodon optatum.

Diet

Diprotodon was probably a browser, feeding on shrubs and forbs. One skeleton from Lake Callabonna had the remains of saltbush in its abdominal region. Diprotodon may have eaten as much as 100 to 150 kilograms of vegetation daily. Its chisel-like incisors may have been used to root out vegetation.

Behavior

In diprotodon, male was considerably larger than the females. There was a high degree of morphological difference between the sexes. In living sexually dimorphic mammals, breeding is usually polygynous i. e. males mate with multiple females over the breeding season. Diprotodon may also have used such a breeding strategy. 

There is some evidence of either predation or scavenging of diprotodon by the Pleistocene marsupial lions.

EXTINCTION

Most modern researchers including argue that diprotodonts, along with a wide range of other Australian megafauna, became extinct shortly after humans arrval in Australia about 50,000 years ago.
The recent ice ages produced no significant glaciation in the mainland Australia but long periods of cold and very dry weather. This dry weather during the last ice age may have killed off all the large diprodonts. But this cannot be the main cause because all the megafauna of Australia died in that same time period. Climate change apparently peaked 25,000 years after the extinctions.
May be the human arrival is the main reason of the extinction of the megafauna in Australia  This species died out just after the arrival of the Human. Diprotodon were herbivorous animals so they lived around the grassland or vegetation. Human also lived in the same habitat. Now Diprotodon drew the carnivores to this habitat which hunted the humans too. To reduce these, human killed diprotodons which also reduced the arrival of the carnivores. The human may also killed them for meat.

Headdress Reconstruction Throws Light on Hunter-Gaththerer Rituals

A research team led by archaeologists at the University of York used traditional techniques to create replicas of ritual headdresses made by hunter-gatherers 11,000 years ago in North Western Europe. Flint blades, hammerstones and burning were among the tools and techniques they employed to fashion reproductions of shamanic headdresses discovered during excavations at the Early Mesolithic site at the Star Carr in North Yorkshire. It is the first scientific analysis of the oldest known evidence of a shamanic costume in Europe. It challenges previously held assumptions over the care and time invested in the modification of the animal's skull cap in order to create these ritualistic artefacts.

Instead the study, part of a five-year project supported by the European Research Council, Historic England and the Vale of Pickering Research Trust, suggests that hunter-gatherers achieved this through expendient manufacturing techniques. These may have involved packing the skull with damp clay and placing it in a bed of embers for up to four hours both to facilitate skin removal and make the bone easier to work. 

Archaeologists unearthed a total  24 red deer headdresses at Star Carr representing around 90 percent of all such known artefacts across early prehistoric Europe. The artefacts are formed the upper part of a male red deer skull with the antler attached - the lower jaw and cranial bones having been removed and the frontal bone perforated. The majority of the headdresses were discovered during archaeological investigations at Star Carr in the 1940s though researchers in earthed a further three during excavations in 2013. The most complete  of these is likely to have come from a male adult red deer though the animal was 50 per cent larger than its modern counterparts.

The first stage of the process may have involved removal of a large amount of antler possibly to reduce the weight of the headdress and make it easier to work. Some of the removed antler may have formed 'blanks' for the production of barbed projectile  tips used for hunting and fishing. But it also possible that, in some cases, antler blank removal happened much later after the headdress had been used; in which case the process may have been a form of decommissioning of the headdress and/or the recycling of antler. The researchers say that given the amount of worked antler. The researchers say that given the amount of worked antler present at Star Carr, including over 200 barbed projectile tips, this is a plausible theory. 

World War I Ships Photographed with Drone Technology

Marine archaeologists with England's Maritime Archaeology Trust used a high-definition vide ogame camera attached to a drone to scan two German warships, V44 and V82. After the war, the two ships were beached at the southern tip of Whale Island, located in Portsmouth Harbour, where they were used for target practice by the Royal Navy gunnery school. The project is known as The Forgotten Wrecks of World War I

Cache of Silver Jewelry Unearthed in Bulgaria

Silver jewelry dating to the second half of the seventeenth century has been unearthed in the northwest Bulgaria by locals who turned it over to the country's National Museum of History. The treasure, which includes a tiara, two forehead adornments, earrings, ear tabs, and rings is thought tho have been hidden  in a leather purse during the Chinarovtsi uprising, when Roman Catholic and Estern Orthodox Bulgarians rebelled against the Ottoman Empire. The region of Chiprovtsi was known for its silver ore, discovered in the fifteenth century and metal smiths. Archaeology in Bulgaria reports that insurgents were crushed by Ottoman troops in 1688 near the modern city of Motana, then known as Kutlovitsa, where the treasure was found.

Women Sacrified in a Temple of Death

Ancient societies on Peru's north coast killed male prisoners of war and drank their blood in grisly sacrifice ceremonies. Now researchers have found an unusual twist on that scene: the remains of six young women, sacrificed in a ritual in about A.D. 850. Their bones were found under the floor of a mudbrick temple complex in Pucala, near the city of Chiclayo. The women show no signs of disease and had been wrenched into odd positions. Four lay atop each other in a single grave, and two others rested a few feet away, accompanied by a baby llama. Most are missing rib bones, indicating that their remains were left exposed and that their organs had ben eaten by vultures after death. a purification rite that the bodies of male sacrifice victims were also subjected to, says archaeologist Edgar Bracamonte of the Royal Tombs of the Sipan Museum.

 Human sacrifices were often public spectacles in ancient Peru, but not in this case. these women were buried in a ritual place which was surrounded by high walls. They were buried on a careful east-west axis. But in the Moche culture, the dead was buried on a north-south axis. In the burial of those women, their heads were towards the Andes Mountains to the east. Ceramics accompanying the women are also from the Andes, suggesting that the women and the society that buried them originated in the mountains and came to the coast by invasion or migration.

New Models Predicting where to Find Fossils

An international team of scientists have developed a way help locate fossils of long-extinct animals.The models were developed for Australia but the researchers provide guideline on how to apply their approach to assist fossil hunting in other continents.

The research team made use of modelling techniques commonly used in ecology. They modeled past distribution of species, the geological suitability of fossil preservation and the likelihood of fossil discovery in the field. They applied their techniques to a range of Australian megafauna that became extinct over the last 50,000 years, such as the giant terror bird Genyornis, the rhino-sized wombat Diproton and the marsupial lion.

To produce the species distribution models of these long-extinct animals, the researchers used 'hindcasted global circulation models' to provide predicted temperature and rainfall for the deep  past and matched this with the estimated ages of the fossils.

In the model they build a probability map for each of these layer -- the species distribution, the right sort of geological conditions for fossil formation and the ease of discovery. They combined each of these for an overall. The methods predict potential fossil locations across an entire continent which is useful to identify potential fossil areas far from already known sites. It's good exploration filter, after which remote-sensing approaches and fine-scale expert knowledge could complement the search.

The model showed areas south of Lake Eyre and weest of Lake Torrens in South Australia and a large area around Shark Bay, Western Australia and other areas in south-western Australia with a high potential to yield new megafauna fossils.

Source: PLOS ONE

Marsupial Lion

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Diprotodontia

Family: Thylacoleonidae

Genus: Thylacoleo

Species: T. carnifex

Temporal Range: Early - Late Pleistocene

The marsupial lion is an extinct species of carnivorous marsupial mammal that lived in Australia.This is the last and largest member of the Thylacoleondae. Despite its name, it is not closely related to the lion, but is a member of the order Diprotodontia.

Description

The marsupial lion is the largest meat-eating mammal known to have ever existed in Australia and one of the largest marsupial carnivores from anywhere in the world. Individuals are about 75 cm high at the shoulder and about 150 cm from head to tail. Its up to 160 kg in weight. 

The animal was extremely robust with powerfully built jaws and very strong fore limbs. It possessed retractable claws, a unique trait among marsupials. This would have allowed the claws to remain sharp by protecting them from being worn down on hard surfaces.The claws were well-suited to securing prey and for climbing trees. The thumbs of each hand were semi-opposable and bore an enlarged claw. This would have been used to grapple its intended prey as well as providing it with a sure footing on tree trunks and branches. The marsupial lion had a relative thick and strong tail. Like the kangaroos, these marsupial lions also used its tail to support itself when on its hind legs. Taking this stance would free up its fore limbs to takle or slash at its intended victim.

The jaw muscle of the marsupial lion jaws exceptionally large for its size, giving it an extremely powerful bite. Biometric calculations shows considering size, it had the strongest bite of any known mammal, living or extinct. a 101 kg individual would have had a bite comparable to that of a 250 kg African lion. The skull was so specialized for big games.It was very inefficient at catching smaller animals.

Habitat

Thylacoleo was widely distributed across Australia during the Pleistocene. It has been found in all Australian states. Most of the sites where Thylacoleo fossils have been found are interpreted as dry, open forest habitat.

 

Evolution

The evolution of these marsupial lions were very interesting. It is believed that the ancestors of the marsupial lions had been herbivores, which is unusual for carnivores but it is confirmed that this Thylacoleonids share a common ancestor with wombats. While other continents were sharing many of their predators amongst themselves, as they were connected by land. Australia's isolation caused many of its normality docile herbivorous species to turn carnivorous. Possum-like features were once thought to indicate that the marsupial lion's evolutionary path was from a phalangeriform ancestor, however, scientists agree that more prominent features suggest a vombatiform ancestry.

Behavior

The marsupial lion was a powerful animal but it was not a particularly fast runner. Most probably the marsupial lions were solitary. Their are not much Social behavior is known about these marsupial lions.

Diet

The diet of the marsupial lions has been the subject of much debate. Thylacoleo has been described as a carnivore, a bone crusher, a scavenger or perhaps even an herbivore. It was first described as One of the fellest and most destructive of predatory beasts.

Recently from CT Scan of their skull we came to know, they had a very good senses of hearing, sight and smell. From this we expect, they are active predators.

Again their unusual teeth and herbivorous ancestry suggested, they are herbivores.

And from the hind leg structure it is confirmed that they are not fast runner, but their body is heavily built which means they can frighten other comparatively small predators and they did that and scavenge food from them.

Now to exist and dominate the landscape every animal uses their all strength. Then why not these marsupial lions. What may be happened was like this -- They are active predators, a deadly scavenger and a herbivore too if needed.

crocodile eggs, carrion, meat and bone marrows were their suggested diet for them. They also take megafauna's as their meal.

The are not suited to catching smaller prey, they are ambush hunter. It would have coexisted with many of the so-called Australian megafauna such as the previously mentioned Diprotodon, giant kangaroos are Megalania as well as giant wallabies like Protemnodon, the giant wombat Phascolonus and the thunderbird Genyornis. All of these Pleistocene megafauna would have been the prey for the marsupial lion who was especially adapted for hunting large animals.

Extinction

 As for most of the Australian megafauna, the events leading to the extinction of T. carnifex remain unclear. The hypothesized causes are the impacts of long-term climate change (both in the higher frequency extreme weather events and more subtle shift in temperature regimes, rainfall patterns etc.), hunting pressure and habitat changes imposed by humans.
When modern humans first arrived in Australia likely more than 60,000 years ago. it is thought that they had substantial impacts on the ecosystem by efficiently hunting large animals and by altering vegetation patterns through fire-stick farming. This has frequently been implicated in the disappearance of the majority of large Australian animals during the Pleistocene. On the other hand, many Australian fossil sites have yielded records of megafauna disappearance well before human presence in the area, giving weight to the interpretation that other factors most likely climate-related were the prominent drivers. The question remains the subject of ongoing research.

Genyornis

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Anseriformes

Family: Dromornithidae

Genus: Genyornis

Species: G. newtoni

Temporal Range: Late Pleistocene

The beak of Genyornis was a large, flightless bird that lived in Australia, over two meters in height, they became 50 thousand years ago. Many other species became extinct in Australia around that time, coinciding with arrival of humans.

Description

Genyomis was a large flightless bird, considerably taller and heavier  than the modern ostrich or emu. It had powerful legs and tiny wings and probably most closely resembled its living relatives duck and geese. But instead of having webbed feet and a duckbill, Genyornis had large hoof-like claws on its toes and a big beak. Like modern birds, it had no teeth but relied on gizzard to assist its digestion. Genyornis was over two meters tall and would weighed from 220-240 kilograms. Eggshell fragments have been recovered in sand dune deposits. The eggs of Genyornis were large, up to 1.6kg, almost twice the volume of emu eggs, smooth in texture and less elongate than emu eggs.

Habitat

Genyornis fossils are known from Lake Callabonna, Baldina Creek, Mt. Gambier, Salt Creek and Naracoorte Caves in South Australia, and from Wellington Caves and Cuddie Spring in New South Wales. Eggshell fragments have been found in dune deposits in South Australia and footprints, possibly those of Genyornis, have been found in Pleistocene dunes in Southern Victoria.
Genyornis had a wide distribution in a variety of habitats but seems to have preferred open forest and savannah-grasslands to more and more closed forest habitat preferred by earlier mihirungs. Eggshell fragments have been found in sand dunes and Genyornis may have used these dunes as nesting sites. A shift  to grasslands and increasing aridification in some areas may have favored the emu in some regions which may then have replaced Gyornis in local faunas.

Diet

The Diet of the whole Dromornithidae family has been the subject of much debate. Many palaeontologists are convinced that dromonithids were mainly if not exclusively herbivorous. Dromornithids lack a hooked beak, as in raptors and have hoof-like rather than recurved claws on their feet. Analysis of eggshells supports an herbivorous diet. Dromornithids are also found in large numbers in some deposits, unlike carnivores which at the top of the food chain, are generally very rare. A minority view holds that dromornithids were to some degree carnivorous, citing the huge size of the beak.
The diet of Genyornis has been determined by any direct evidence although  it appears to have been herbivorous. Fossils of Genyornis have been found with pebbles in the gizzard region, which are unknown in carnivores. Gastroliths wold have been used to help break up its food, as they do in other herbivorous birds. It is quite possible, given its anatomy and discovery of gastroliths, that Genyornis was herbivorous but the larger Bullockornis and Dromornis had a more varied diet.

Evolution 

Once thought to be ratites, dromornithids are now believed to be either within Anseriformes or just basal to  it. Recent revisions of the taxonomy of other large, flightless birds place these taxa within Anseriformes. All of these large birds, including the dromornithids, have a short dentary symphysis and a dorsally directed pterygoid process on the quadrate, unusual features not related to flightlessness. This revision is still debated, although many feel that the general placement of at least dromornithids, somewhere near the base anseriform radiation has merit.

Life Cycle

The eggs of Genyornis have been found in sand dune deposits which have also preserved the eggshells of emus. These dunes may have served as breeding grounds for both species, Hole similar to those made by mammalian canine teeth have been found in some Genyornis eggshell fragments. The size of these holes suggests that the predators were either Tasmanian devils or eastern quolls, both of which are known from the dune deposits.

Extinction

Human impact and climate change are the main two reason behind the extinction of this birds. A study has been performed in which more than 700 Genyornis eggshell fragments were dated. Through this, it was determined that Genyornis declined and became extinct over a short period. That short period is so short that climate change can not be the only and definitely the main reason behind that extinction. According to research studies, it is confirmed that the extinction of this birds in Australia was due to human activity rather than climate change. Human killed this bird for meat and they also take their eggs for meal. many eggs were found burned in fire (they are well cooked) which means human took those as meal.

Megatherium

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pilosa

Family: Megatheriidae

Genus: Megatherium

Species: M. amerucanum

               M. medinae

               M. istilarti

               M. parodii

               M. sundti

               M. gallardoi

Temporal Range: Middle Pliocene to Early Holocene

Megatherium was a genus of ground sloths endemic to South America that lived from the Middle Pliocene through the end of the Pleistocene. Megatherium means great beast. Its size was exceeded by only a few other land mammals, including mammoths and paraceratherium.

The first fossil specimen of this creature was discovered in 1788 by Manuel Torres, on the bank of the Lujan river in Argentina.

Evolution

During the Pliocene, the Central American Isthmus formed, casing the Great American Interchange, and a mass extinction of much of the South American megafauna. Ground sloths were largely unaffected and continued to thrive in spite of competition from the northern immigrants. Ground sloths among the various South American animal groups to migrate northwards into North America, where they remained unflourished until the Late Pleistocene.

Promegatherium is suggested as the ancestor of Megatherium. The oldest species of Megatherium is M. altiplanicum of Pliocene. It was very similar to Promegatherium and was also about the same size. M. tarijense has been regarded as a medium-sized Megatherium species, larger than M. altiplanicum but smaller than M. americanum. It roamed from Bolivia to Peru. Species of Megatherium became larger over time with largest species M. americanum of the late Pleistocene. It was about the size of an African  Elephant.

Description

Megatherium weighing up to 4 tonnes and mesuring up to 6 m in length from head to tail. It is largest known ground sloth and would have only been exceeded in its time by a few species of mammoth. It has a robust skeleton with a large pelvic girdle and a broad muscular tail. Its large size enabled it to feed at heights unreachable by other contemporary herbivores. It could support its massive body weight while using the curved claws on its long forelegs to pull down branches with the choicest leaves. Studies also suggest that it had adaptations to bipedalism. Some experts believe that its jaw may have housed a long tongue which it would use to pull leaves into its mouth, similar to the modern tree sloth.It was well adapted for strong predonimatly orthal movement for eating rough vegetation. It was a selective eater.

 

Habitat

Megatherium inhabited woodland and grassland environment of the lightly wooded areas of South America where it was an endemic species, as recently as 10000 years ago. According to the fossil study, it is believed that they were adaptable to temperate, arid or semiarid open habitats.

Behavior

The giant ground sloth lived mostly in groups, but it may have lived singly in caves. It probably had mainly a browsing diet in open habitats, but also it  probably fed on other moderate to soft tough food. For millions of years, the sloth did not have many enemies to bother it, so it was probably a diurnal animal.

Predators

Because of its size and its deadly claws there are not much predators of this sloth. Though from some studies it is come to know that the Saber tooth cats took sloths as their diet. Now another recent research also indicates that Saber tooth cat also hunt in the lands of South America. So it is very much likely that the saber tooth cat is may  be the only predator that have a chance against this massive creature.

Diet

 They were herbivore animal; feeding on leaves such as yuccas, agaves and grasses. While it fed chiefly on terrestrial plants, it could also stand on its hind legs, using its tail as a balancing tripod. and reach for upper growth vegetation. The sloth's stomach was able to digest coarse and fibrous food. It is likely that it spent a lot of time resting to aid digestion.

 

Extinction

In the south, the giant ground sloth flourished until about 10,500  BP. Most cite the appearance of an expanding population of human hunters as the cause of its extinction. There are a few dates of around 8000 BP and one of 7000 BP for megatherium remains, but the most recent date viewed as credible is about 10,000 BP. The use of bioclimatic envelope modeling indicates that the area of suitable habitat for Megatherium had shrunk and become fragmented by the mid-Holocene. While this alone would not likely have caused its extinction. it has been cited as a possible contributing factor.

Hapalops

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Xenarthra

Family: Megatheriidae
Species: H. indifferens
               H. longiceps
               H. latus
               H. cadens
               H. congermanus
               H. gallaicus

Conservation Status: Extinct

Temporal Range: Late Oligocene - Miocene

Hapalops is extinct genus of ground sloth from the late Oligocene of South America. Though related to the giant Megatherium, Hapalops was much smaller, measuring about 1 meter in length. Like most extinct sloths it is categorized as a ground sloth, but it is believed that the smaller size of Hapalops allowed it to engage in some climbing behaviors.

It had a robust body, short skull and long limbs with large, curved claws. When it did visit the ground the animal probably walked on the knuckles of its forelimbs, like gorilla. Hapalops had very few teeth with no incisors, the mandible included only four pairs of teeth.

Eremotherium

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pilosa

Family: Megatheriidae

Genus:  Eremotherium

Species: E. laurillardi

               E. eomigrans

               E. rusconi

Temporal Range: Late Pliocene - Pleistocene

Eremotherium is an extinct genus of ground sloth of the family Megatheriidae, endemic to North America and South America during the Pleistocene epoch. It roamed the planet for about 5 million years. It is a solitary beast.

It is about 6 meters long herbivore animal with long deadly claws. It is one of the largest ground sloth of all time.

The fossils have been uncovered from Chaltham County, Georgia, Berkeley County, South Carolina; Espirito Santo, and Pedra Preta, Brazil; Tarapoto, Peru; Rio Canas, Ecuador.

 E. eomigrans fossil was found in Florida only. It lived from 4.9 mya - 300,000 years ago. (4.6 million years)

E. laurillardi fossil was from the southern U.S. to Brazil. It lived from 780,000 - 11,000 years ago. (0.769 million years)

Combodia Raises Hope for Asian Species in the Wild

Rare footage of a n elephant herd roaming through Cambodia's biggest forest sanctuary has signaled the Success of a 14 year conservation programme and raised hopes for the endangered species' survival. The footage shows 12 elephants, including young, grazing and lumbering through the forest. 

Conservation International released the footage on Friday as it launched a trust fund that aims to secure long term funding for the scheme in one of south-east Asia's most biodiverse areas.

 

The several young are here indicates that the elephants are reproducing which is a good sign that their environment is stable and they are not under stress. The footage was taken a few months ago, was the first time so many elephants had been captured on film in the Caradamoms which is home to about one third of Cambodia's endangered and rare species. 

There are believed to only be about 200-250 elephants in the Cardamoms with another population of similar size in eastern Cambodia. 

Source: The Guardian

Tigers are Extinct from Cambodia

Finally Tigers are officially declared extinct from the jungles of Cambodia. The last Tiger was seen in the Eastern Mondulkiri province in 2007 on camera trap.

 

Cambodia's dry forest used to be home to scores of Indochinese tiger but the WWF said intensive poaching of both the tigers and its prey had devastated the numbers of tigers. Today there are no longer any breeding populations of tigers left in Cambodia,and they are therefore considered functionally extinct.

In effort to revive the population of tiger the government of Cambodia approved a plan to reintroduced this magnificent creature into the Mondulkiri protected forest in the far of east the country. The plan will see a chunk of suitable habitat carved out and protected against poachers by strong law enforcement. 

To execute this huge project two male and six female tigers needed for start. The government needs $20 to $50 for the project.

Source: The Guardian

Homo floresinerensis Wiped Out Sooner Than Thought

 

According  to a study, an ancient species of pint-sized humans discovered in the tropics of Indonesia may met their demise earlier than once believed. 

According to the report, Flores island co-existed with modern humans for tens of thousands of years. They seems to have disappeared soon after our species reached Flores which suggesting it as who drove them to extinction.

After testing their age it is confirmed that their disappearance occurs about 50,000 years ago.

Source: Nature

Megatheriidae

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
 Family: Megatheriidae

It is family of ground sloths that extinct from the world about 11,000 years ago. It roamed on the lands of today's North America and South America. It came into existence about 23 million years ago and existing for approximately 22.89 million years.

Megatheriids appeared in the early Oligocene some around 25 million years ago. The group includes the heavily built Megatherium and Eremotherium. An early megatheriid, Hapalops reached a length of about 1.2 meters.

From the structure of the skeleton of megatheriid it is confirmed that they were massive. Their thick bones and even thicker joints gave their appendages tremendous power that combined with their size and fearsome claws, provided a formidable defense against predators.

Family Tree

Megatheriidae

• Eremotherium
• Hapalops
• Megatherium
• Prepotherium
• Promegatherium
• Pelecyodon

Mechanism of Slow Earthquakes Reproduce

catching lightning in a bottle has been easier than reproducing a range of earthquakes in the laboratory, according to a team of seismologists who can now duplicate the range of fault slop modes found during earthquakes, quiet periods and slow earthquakes.

Catastrophic earthquakes, the kind that destroy buildings and send people scurrying for doorways and safe locations are caused when two tectonic plates that are sliding in opposite directions stick and then slop suddenly, releasing a large amount of energy, creating tremors and sometimes causing destruction. Along regions of faults that do not produce earthquakes, the two sides of the fault slowly slip past each other in a stable fashion. Slow earthquakes occur somewhere between the stable regime and fast stick slip.

Regular earthquakes take place rapidly, while slow slow earthquakes occur on time scales that may range up to  months. They can be as large as magnitude 7or more and may be precursors to regular earthquakes. However, slow earthquakes propagate slowly and do not produce high-frequency seismic energy. They exist in the regime between stable slipping and regular earthquakes.

The researchers applied stress perpendicular to the direction of shear and then applied forces to shear the ground quartz. By altering the amount of stress placed in the perpendicular direction,they could achieve the audible crack of a regular earthquake, stable slippage and a wide range of slip-stick behaviors including slow earthquake.

How Insects repair their bones

Bio-mechanics researchers have discovered that insects repair their injured bodies by deploying a DIY cuticle repair kit after meeting with mishap. Repaired limbs provide around two-thirds of their original strength which helps individuals from the world's most diverse group of animals to survive in the wild. The study is the first to ever assess the biomechanics of repair in arthropods.

Source: The journal of Royal Society Interface

Linnaeus's two-toed Sloth

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pilosa

Family:  Megalonychidae

Genus: Choloepus

Species: C. didaactylus

Conversational Status: LC (Least Concern)

Linnaeus's two-toed sloth is a species of sloth from South America. This species is also known as Southern two-toed sloth or unau.

Characteristics

This species is larger than three-toed sloths. They have longer hair, bigger eyes, and their back and front legs are more equal in length. Their ears, hind feet and head is generally larger than Bradypodidae. They do however have a shorter tail. Their shoulder height, the height from the shoulder blade to the tips of the claw is longer than three-toed sloths, indicating longer arms.

 

Habitat

They are found in the Wild of Venezuela, Guyanas, Colombia, Ecuador, Peru and Brazil north of the Amazon River. Recently, there are evidence that suggests that this species's range expands into Bolivia.

 Behavior

 It is a solitary, nocturnal and arboreal animal, found in rainforest. It is able to swim, making if possible to cross rivers and creeks. They live in ever-wet tropical rainforests that are hot humid. They tend to live in areas where there is a lot of vine growth so they can easily travel from tree to tree in the canopies of the forests. They mainly eat leaves, but there is lacking data on the extent of their diet due to their nocturnal lifestyle and camouflage. 

Predator

The two-toed sloth falls prey to wild cats such as the ocelot and jaguar as well as large birds of prey such as the harpy and crested eagles. Predation mainly occurs when the sloth descends to the ground in order to defecate or change trees. Anacondas have been known to hunt sloths.

Life Cycle

Linnaeus's two toed sloth has a ten-month gestation period. Their inter-birth rate extends past sixteen months so there is not an overlap pf young to care for. There is only one offspring per litter and the young becomes independent at about a year old. It take longer for two-toed sloths to become independent as well as the gestation period is longer than in three-toed sloths, It has been suggested that this difference may be caused by their difference in diet.

Hoffmann's Two-Toed Sloth

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pilosa

Family: Megalonychidae

Genus: Choloepus
Species: C. hoffmanni

Conservation Status: LC (Least Concerned)

Hoffmann's tow-toed nocturnal and arboreal animal, found in mature and secondary rainforests and deciduous forests. The common name commemorates the German naturalist Karl Hoffmann.

Description

This sloth is a heavily built animal with shaggy fur and slow, deliberate movements. The fore feet have only two toes, each ending with long, curved claws, The three toes sloth also have these same characteristics which may be found in the same geographic areas, but there are some characteristics that definitely distinguished them from the two toed sloths. Those characteristics include they have the longer snout, separate rather than partially fused toes of the forefeet, the absence of hair on the soles of the feet, and larger overall size. The wrist of the sloth has developed some specific traits due to their slow, yet acrobatic motions. These evolved traits include diminution and distal migration of the pisiform bone. with a loss of contact with the ulna; reduction of the distal end of the ulna to a styloid process, and extremely reduced contact between the ulna and triquetral bone.

This Hoffmann's two-toed sloth is very much related with Linnaeus's two-toed sloth. These two are also very closely resembles. The primary physical differences between the two species relate to suitable skeletal features.
Adults range from 54 to 72 cm in head-body length and weigh from 2.1 to 9 kg. Although they do not have stubby tails, just 1.5 to 3 cm long, this is too short to be visible through the long fur. The claws are 5 to 6.5 cm long. Females are larger on average than males, although with considerable overlap in size. Their fur is tan to light brown in colour, being lighter on the face, but usually has a greenish tinge because of the presence of algae living in the hairs.

Habitat

this sloth inhabits tropical forests from sea level to to 3300 m above sea level. It is found in the rainforest canopy in two separate regions of Central and South America, separated by the Andes. One population is found from eastern Honduras in the north to western Ecuador in the south and the other in eastern Peru, Western Brazil and northern Bolivia. According to the study a divergence date of about 7 million years between these populations has been suggested.

 

Behavior

Two-toed sloth spend most of their time in trees, through they may travel on the ground to move to a new tree. A new study suggests on Barro Colorado Island, these species of sloth is exclusively nocturnal, even though in other locations they are known to be active during day. This is may be because of the competition with brown-throated sloth. They often move slowly through the canopy for about eight hours each night, and spend much of the day sleeping in tangles of lianas, They move only very slowly, typically at around 0.14 m/s, although they can move up to 50% faster when excited. They are solitary in the wild and aside from mothers with young, it is unusual for two be found in a tree at the same time.
Sloths have very poor eyesight and hearing and rely almost entirely on their sense of touch and smell to find food. This sloth is often spits when the mouth opens.

Diet

Their main source of diet is tree leaves. Though they also eat fruits and flowers. Sloths have three chambered stomachs. A sloth may take up to a month to completely digest a meal and up to two-thirds of a sloth's weight may be the leaves in its digestive system.

Predators

Sloths have many predators, including the jaguars, ocelots, harpy eagles, margays and anacondas.. If threatened, sloth s can defend themselves by slashing out at a predator with their huge claws or biting with their sharp cheek teeth. However, a sloth's main defense is to avoid being in the first place. The two-toed sloth can survive wounds that would be fatal to another mammal its size. The sloth's slow, deliberate movements and algae-covered fur make them difficult for predators to spot from a distance. Their treetop homes are also out of reach for many larger predators.

 

Life Cycle

Courtship consists of the female licking the male's face and rubbing her genitals against the male's body. Gestation lasts between 355 and 377 days, and results in the birth of a single young. The birth takes place in either the ground or in the hanging position. Newborn sloths weight 340 to 454 g. from birth they have long caws and able to cling to their mothers' undersides. The begin to take solid food at 15 to 27 days and are fully weaned by 9 weeks. young sloths make loud bleating alarm calls if separated from their mothers.
Hoffmann's sloth reach sexual maturity at two to four years of age and have been reported to live up to 32 years in captivity.

Conservation Status

Habitat destruction is probably causing a decrease in the wild Hoffmann's two-toed sloth population but little reliable data is available on the number of wild individuals. Sloths and people have little contact with one another in the wild.