Planet of prehistory

Helicoprion

2012-06-22T17:31:00.002+07:00

Helicorprion also known as "the spiral saw" is said to have lived during the carboniferous period and one of the few creatures able to live through the Permian-Triassic extinction or so called "the great dying".Eventually Helicoprion extinct during the Triassic period.Though not many fossils were found. Archaeologist have found the tooth-whorl as well as jaw bones. With these, researchers have pieced together ideas of what the Helicoprion may have looked like. One thing we know for sure is that the creature has teeth that are very much like circular saw, which was connected on the lower jaw. It has many teeth because as new teeth grew, the older ones get pushed out and into the middle to create the spiral. Length-wise is said to be about 10-15 feet. What a bizarre creature.

The Helicoprion was said to be extremely shark-like, having cartilage,fins,and razor sharp teeth.In fact some believe that the creature was a shark itself,but there is not enough evidence to prove this.

Maiasaura

2012-01-05T10:37:00.001+07:00

Maiasaura, a Hadrosaurid genus, famous as a "good mother lizard," lived in North America about 75 million years ago, probably the direct ancestor of the Hadrosaur Edmontosaurus. It was named by Jack Horner and Robert Makela in 1979. Astronaut Loren Acton took a bone fragment and eggshell piece of a Maiasaura on an 8-day Spacelab 2 mission in 1985—the first dinosaur in space!

http://jurassicpark.wikia.com/wiki/Maiasaura

Quetzalcoatlus

2012-01-04T12:56:00.001+07:00

Quetzalcoatlus was a huge pterosaur with a wingspan of up to 15 metres - the largest flying creature of all time. It is the last known pterosaur which survived to the very end of the Cretaceous period. Quetzalcoatlus was named after the Aztec's feathered-serpent god, Quetzalcoatl, by Douglas Lawson who first found the remains at Big Bend National Park in Texas.

Despite its huge size, the skeleton was lightly built and the whole animal probably weighed no more than 100 kilograms. Its neck was extremely long, its slender jaws were toothless and its head was topped by a long, bony crest. Unlike most other pterosaur fossils the Quetzalcoatlus remains have not been found in marine strata but in the sand and silt of a large river's flood plain and this has raised questions about how it lived.

It was a good soarer - certainly able to cover large distances. This, coupled with its long neck has prompted the idea that it lived rather like a vulture and fed on the corpses of dead dinosaurs. But some palaeontologists, noting the long slender jaws suggest that it probed soft ground and pools for molluscs and crustaceans. Others think that it flew low over the warm shallow seas plucking fish from the surface.

http://www.abc.net.au/dinosaurs/fact_files/volcanic/quetzalcoatlus.htm

Carnotaurus

2012-01-03T17:08:00.001+07:00

Carnotaurus was a large dinosaur predator that lived in South America during the Late Cretaceous Period. It is a relative of another theropod dinosaur from Madagascar called Majungasaurus(formerly Majungatholus). Characteristics of Carnotaurus include their very small hands as well as horns above their eyes, and a short snout. Females are usually smaller and have smaller horns. Males use their horns in fights with other males, as well as use their mating season camo, to impress females. When compared to their body size, the arms of the Carnotaurus were smaller even than those of the T. rex. One of the main prey for this dinosaur wasSaltasaurus, a medium-sized sauropod with armor. It had the most smallest arms out of all dinosaurs.

http://jurassicpark.wikia.com/wiki/Carnotaurus

Fossil Facts

2012-01-03T10:55:00.000+07:00

Fossils are what's left of plants and animals that were alive a long time ago. When the plant or animal died, part of it was left on the earth. That part became trapped in the sediments, and the sediments became rock. Once the rock formed, the fossil was trapped inside. Some fossils are destroyed because sediments undergo a lot of heat and pressure when they become rocks, and the heat and pressure might destroy the fossils. Most fossils are found in sedimentary rocks.

There are two types of fossils: vertebrate and invertebrate. Vertebrate fossils come from animals that had bones. Invertebrate fossils come from plants or animals that didn't have bones.

Sometimes fossils are parts of bodies like bones and teeth. Sometimes they are parts of leaves. Other times they might be animal tracks.

When a plant or animal leaves a shape, that shape is called a mold. If mud or minerals fill the mold and harden, that's called a cast. It has the same shape that the animal or plant had when it was alive. Imprints are molds of thin objects like leaves. Wings and feathers can also leave imprints because they are very thin.

A fossil isn’t the actual bone or leaf or other object that was left. Instead, it’s just an object that’s the same shape as the original item. It’s made up of various minerals and other material that has hardened.

We can use fossils to help us learn about the animals or plants that have died. This kind of study is called paleontology. Scientists have used fossil bones to put together skeletons of dinosaurs and other animals. We can tell how large they were and how they walked by looking at the skeletons. The teeth of the fossils show what kinds of foods they ate. Sharp teeth probably mean the dinosaurs ate meat (other dinosaurs). Flat teeth probably mean the dinosaurs ate plants.

Amebelodon

2012-01-03T10:40:00.001+07:00

Amebelodon is a member of a diverse group of primitive proboscideans called gomphotheres, a group that also gave rise to the modern elephants and their close relative the mammoth. The most striking attribute of this animal is its lower tusks, which are narrow, elongated,and distinctly flattened with the degree of flattening varying among the different species. Amebelodon first appeared in the Great Plains and Gulf Coast regions of North America during the late Miocene, roughly between 9 and 8 million years ago, and apparently became extinct on this continent sometime around 6 million years ago. It managed to migrate to Asia via theBering land bridge where it has been found in a number of late Miocene sites, particularly in China. The youngest record of Amebelodon is from a 5 million year old site in North Africa.

http://en.wikipedia.org/wiki/Amebelodon

weekly video

2012-01-02T19:18:00.000+07:00

Anatotitan

2012-01-02T19:16:00.001+07:00

Anatotitan ( /əˌnætɵˈtaɪtən/ ə-nat-o-ty-tən; "large duck") is a genus of flat-headed or hadrosaurine hadrosaurid ornithopod dinosaur (a "duck-billed dinosaur") from the very end of the Cretaceous Period, in what is now North America. Remains of Anatotitan have been preserved in the Hell Creek and Lance Formations, which are dated to the late Maastrichtian stage of the Late Cretaceous Period, representing the last three million years before the extinction of the dinosaurs (68 to 65 million years ago). This dinosaur is known from at least six specimens pertaining to two species, discovered in the U.S. states of South Dakota and Montana. Several of these specimens are extremely complete skeletons with well-preserved skulls. It was a large animal, up to approximately 12 meters (39 ft) in length, with an extremely long and low skull.Anatotitan exhibits one of the most striking examples of the "duckbill" snout common to hadrosaurs. It has a long taxonomic history, including decades classified with the genera Anatosaurus, Diclonius, and Trachodon.

http://en.wikipedia.org/wiki/Anatotitan

Cenozoic(New life) era

2012-01-02T17:37:00.000+07:00

The last and most recent of the geologic periods is the Cenozoic Era. Its name means “new life” coming from the Greek root kainos, meaning “new,” and zoic, “life.” While this new life came to refer to mammals-thus coined The Age of Mammals- this new life could have just as easily been the angiosperm or flowering plants, the insects, the newest fish (teleostei) or modern birds. All of these groups, including the mammals, continued to evolve during this present Era.

http://www.fossils-facts-and-finds.com/cenozoic_era.html

Mesozoic(Middle life) era

2012-01-02T17:33:00.000+07:00

This is the second of three geologic eras squeezed into the Phanerozoic ("Evident Life") Eon that covers the last 10% of Earth's whole geologic history. This is the era we all think of when we imagine the Ancient Earth! Rampaging dinosaurs! Dive-bombing pterodactyls! Endless forests of giant ferns! Erupting Volcanoes! (Sorry, no cave men! They didn't show up until the end of the Cenozoic.)

The Mesozoic Era lasted about 180 million years, from about 245 million years ago to about 65 million years ago. The Mesozoic is divided into just three time periods: the Triassic, the Jurassic, and the Cretaceous. Since lots of things were going on in each time period, we can only summarize the events. You can learn more by going to your library or searching the Internet for words like "Mesozoic" or the names of each of the periods.

In the view above, we see Earth in the middle of the Jurassic Period, in mid-Mesozoic times (sort of a middle-middle view). The supercontinents Gondwanaland and Laurasia collided some time back to form a single super-super continent called Pangea ("All-Earth"). But plate tectonics continues its irresistible motions, and even as we look, Pangea is beginning to break up into the continents we know now. At upper left, North America is just breaking away from the northwest coast of Africa, and the Atlantic Ocean and Gulf of Mexico are beginning to form. The Appalachian Mountains of the eastern United States are a high, rugged mountain range, something like the Rocky Mountains of today. Over the next fifty million years or so, South America, India, and Antarctica will all break away from Africa and move toward their present positions.

Life is diversifying rapidly, and beginning to look familiar. The dominant animals on both land and sea are reptiles, the most famous of which are the dinosaurs. Dinosaurs began in the Triassic, spread during the Jurassic, and dominated Earth in the Cretaceous. They are so prominent that the Mesozoic is also called "The Age of Reptiles." But dinosaurs are not the only life form around: birds and mammals also appear during the Mesozoic, as well as deciduous trees and flowering plants.

The climate during the Mesozoic is warm; so warm that there are no ice caps at all, even at the poles! Plants grow like crazy in the warmth and moisture, so there is food everywhere for your average hungry 50-ton Ultrasaurus! So what happened to this Dino Paradise? More change! A mass extinction like those in thePaleozoic ended the idyllic Mesozoic Era (if you can call dodging your friendly local T-Rex as idyllic). More than half of all existing life forms disappeared, including virtually all of the dinosaurs. Why? There are many hypotheses, including disease, volcanic eruptions, and giant impacts. (Pay a visit to the Dinosaur Floor to learn more.

http://www.cotf.edu/ete/modules/msese/earthsysflr/mesozoic.html

Paleozoic(Ancient life) era

2011-12-27T12:35:00.000+07:00

The Paleozoic is bracketed by two of the most important events in the history of animal life. At its beginning, multicelled animals underwent a dramatic "explosion" in diversity, and almost all living animal phyla appeared within a few millions of years. At the other end of the Paleozoic, the largest mass extinction in history wiped out approximately 90% of all marine animal species. The causes of both these events are still not fully understood and the subject of much research and controversy. Roughly halfway in between, animals, fungi, and plants alike colonized the land, the insects took to the air, and the limestone shown in this picture was deposited near Burlington, Missouri.

The Paleozoic took up over half of the Phanerozoic, approximately 300 million years. During the Paleozoic there were six major continental land masses; each of these consisted of different parts of the modern continents. For instance, at the beginning of the Paleozoic, today's western coast of North America ran east-west along the equator, while Africa was at the South Pole. These Paleozoic continents experienced tremendous mountain building along their margins, and numerous incursions and retreats of shallow seas across their interiors. Large limestone outcrops, like the one shown above, are evidence of these periodic incursions of continental seas.

Many Paleozoic rocks are economically important. For example, much of the limestone quarried for building and industrial purposes, as well as the coal deposits of western Europe and the eastern United States, were formed during the Paleozoic.

http://www.ucmp.berkeley.edu/paleozoic/paleozoic.html

Kronosaurus

2011-12-20T18:54:00.001+07:00

Kronosaurus was the largest marine reptile that ever lived. It belonged to the category of plesiosaur, which is a meat-eating reptile. As considered by most of us, Kronosaurus is not a dinosaur, it is a plesiosaur. It was known to have been lived in the early cretaceous period and it belonged to the Dolichorhynchopidae family. It is known to have been lived around 110 million years ago. The term Kronosaurus was derived from the Greek word and the meaning of the term is krono's lizard. Kronos was known to be the Greek god of time, who is known to have eaten his own children for the purpose of guarding his powers. The term Kronosaurus is pronounced as crow-no-sore-us. Kronosaurus is known to have been lived in the country of Australia and it was a highly skilled swimmer. Apart from Australia , these plesiosaurs would have been lived in South America and Columbia as well. The fossils of Kronosaurus were found in Queensland , Australia in the year 1889 and it was found by A. Crombie. It was named in the year 1924 by Longman.

Kronosaurus were known to be the ferocious predators of the sea and it would have been lived in the open oceans, but would have also required swimming to thesurface since it was an air breathing reptile. They might have been able to move a little in the land like seals.

From the fossils of Kronosaurus, it was found that it would have got a pointed tail, short neck with four long flippers and a huge head. It has a rounded teeth and strong jaws and tooth of the Kronosaurus was so strong that it would easily crush the shells. The four paddle-like flippers had enabled the Kronosaurus to move around water like sea turtles. The diet of these plesiosaurs was large squids, ichthyosaurs and sharks. It was known to have been around 30 feet (i.e.) 9m long. The head of Kronosaurus alone was around 9 feet (i.e.) 1/3 rd of the total body length. It has been found that it would have been weighed around seven tons. Even though, the Kronosaurus were known to have been lived in oceans, it would have swim to the surface for laying eggs as is being done by turtles nowadays. Like turtles, Kronosaurus has also laid eggs in nests dug in the sand.

According to a research Kronosaurus made its living just like the present day shark in such a way that it had eaten every all animals living in the water coming in its way. It has been found that it did not restrict itself in eating just squids and fish, but feasted occasionally with other aquatic reptiles as well.

From the fossils of Kronosaurus, researchers have found some stones in theirstomach and they assumed that these stones might have been consumed by the Kronosaurus for grinding up their food or the stone might have also been used as ballast for the purpose of diving. Hope, you might have got the required information regarding Kronosaurus.

http://www.dinosaurfact.net/Marine/Kronosaurus.php

Megalania

2011-12-19T20:43:00.001+07:00

Megalania prisca, the largest terrestrial lizard known, was a giant goanna (monitor lizard). First described from the Darling Downs in Queensland by Sir Richard Owen in 1859, Megalania lived in a variety of eastern Australian Pleistocene habitats - open forests, woodlands and perhaps grasslands.Megalania would have been a formidable reptilian predator like its relative the Komodo Dragon of Indonesia, and may have eaten large mammals, snakes, other reptiles and birds.

http://australianmuseum.net.au/Megalania-prisca

stegodon

2011-12-19T20:28:00.001+07:00

The name Stegodon is derived from the Greek words στεγειν stegein ("to cover") and οδον odοn ("tooth") because of the distinctive ridges on the animal's molars. In the past, stegodonts were believed to be the ancestors of elephants and mammoths, but it is currently believed that they have no modern descendants. Stegodon is derived from the genus 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.

Stegodonts lived in large parts of Asia during the Pliocene and Pleistocene epochs. Some Stegodon species were among the largest of all Proboscidea, with adults being 13 feet high at the shoulder, 26 feet long, with 10 feet long nearly straight tusks. In some individuals, the tusks were so close together that the trunk probably did not lie between them but instead draped over.

weekly video

2011-12-19T20:21:00.000+07:00

Mosasaurus

2011-12-19T20:19:00.001+07:00

Mosasaurus was a large, 15-metre long aquatic carnivore from the Late Cretaceous about 90-65 million years ago. It gave its name to a group of marine lizards - Mosasaurs. Mosasaurus means 'Meuse Lizard', referring to where it was first found. It fed on such prey as sea birds, sharks and large fish, Plio/Plesiosaurs and even other Mosasaurs.

weekly video

2011-11-12T20:52:00.000+07:00

Elasmotherium

2011-11-12T20:47:00.001+07:00

Elasmotherium("thin plate beast") is an extinct genus of giant rhinoceros endemic to Eurasia during the late Pliocene through the Pleistocene, documented from 2.6 mya to as late 50.000 years ago, possibly later, in the late Pleistocene, an approximate span of slightly less than 2.6 million years. three species were recognized. the best known, E. sibiricum was the size of a mammoth, an is thought to borne a large, thick horn on its forehead which was used for defense, attacking mates, driving away competitors, sweeping snow from grass in winter and digging for water and plant roots. Like all rhinoceroses, elasmotheres were herbivorous. Unlike any others, its high-crowned were ever-growing. Its legs were longer those of other rhinos and were designed for galloping, giving him a horse-like gait. The Russian paleontologist of the 19th century who discovered and named the initial fossils were influenced by ancient legends of a huge unicorn roaming he steppes of Siberia. To date no evidence either contradicts or confirms the possibility that Elasmotherium survived into legendary times.

http://en.wikipedia.org/wiki/Elasmotherium

Ultrasaurus

2011-10-22T23:50:00.001+07:00

This article is about the dubious dinosaur genus from South Korea. For the invalid dinosaur genus from Colorado, see Ultrasauros.

Ultrasaurus is a genus of sauropod dinosaur discovered by Haang Mook Kim in South Korea. However, the name was first used unofficially (as anomen nudum) in 1979 by Jim Jensen to describe a set of giant dinosaur bones he discovered in the United States. Because Kim published the name for his specimen before Jensen could do so officially, Jensen renamed his specimen Ultrasauros. Jensen's giant sauropod was later found to be a chimera, and the type remains are now assigned to Supersaurus.

http://en.wikipedia.org/wiki/Ultrasaurus

American Lion

2011-10-22T23:43:00.001+07:00

The term "American lion" has sometimes been used to mean the cougar.

This article is about the feline. For the Pulitzer-winning biography, see American Lion (book).

The American lion (Panthera atrox) — also known as the North American lion or American cave lion — is an extinct feline of thefamily Felidae, endemic to North America during the Pleistocene epoch (1.8 mya to 11,000 years ago), existing for approximately1.79 million years.^[1] While it was once considered a subspecies of lion closely related to the Eurasian cave lion (Panthera leo spelaea),^[2] later study showed that it was not in fact a true lion and cannot be assigned to any modern species of cat.^[3]

The American lion was one of the largest types of cat ever to have existed, slightly larger than the Early Middle Pleistocene primitive cave lion, P. leo fossilis and about twenty-five percent larger than the modern African lion.^[4]

http://en.wikipedia.org/wiki/American_Lion

Smilodon

2011-10-22T23:36:00.001+07:00

The species of Smilodon were among the largest felids ever to live; the heaviest specimens of the massively built carnivore S. populator may have exceeded 500 kg (1,100 lb).^[4]

A fully-grown Smilodon weighed approximately 55 to 470 kg (120 to 1,000 lb), depending on species. It had a short tail, powerful legs, muscular neck and long canines. Smilodon was more robustly built than any modern cat, comparable to a bear. The lumbar region of the back was proportionally short, and the lower limbs were shortened relative to the upper limbs in comparison with modern pantherine cats, suggesting that Smilodon was not built for speed.

The largest species, the South American S. populator, had higher shoulders than hips and a back that sloped downwards, superficially recalling the shape of a hyena, in contrast to the level-backed appearance of S. fatalis, which was more like that of modern cats. However, while its front limbs were relatively long, their proportions were extremely robust and the forearm was shorter relative to the upper arm bone than in modern big cats, and proportionally even shorter than in S. fatalis. This indicates that these front limbs were designed for power rather than fast running, and S. populator would have had immense strength in its forequarters.

[edit]Limbs

S. populator skeleton

Smilodon had relatively shorter and more massive limbs than other felines. It had well developed flexors and extensors in its forepaws,^{[citation needed]} which enabled it to pull down large prey.^[7] The back limbs had powerfully built adductor muscles which might have helped the cat's stability when wrestling with prey. Like most cats, its claws were retractable.

[edit]Teeth and jaws

Skull and neck at the AMNH

Smilodon is most famous for its relatively long canines, which are the longest found in the sabre-toothed cats, at about 28 cm (11 in) long in the largest species Smilodon populator.

These canine teeth were fragile and could not have bitten into bone; thus, these cats did not use their long teeth while taking down prey, due to the risk of breaking them. Only when their prey was totally subdued did they use their teeth to simultaneously sever the blood supply and strangle the windpipe, instantly killing the prey.^{[citation needed]}

Despite being more powerfully built than other large cats, Smilodon actually had a weaker bite. Modern big cats have more pronouncedzygomatic arches, while Smilodon had smaller zygomatic arches which restricted the thickness and therefore power of the temporalis muscles, and thus reduced Smilodon’s bite force. Analysis of its narrow jaws indicates that it could produce a bite only a third as strong as that of a lion.^[8] There seems to a be a general rule that the sabre-toothed cats with the largest canines had proportionally weaker bites. However, analyses of canine bending strength (the ability of the canine teeth to resist bending forces without breaking) and bite forces indicate that sabre-toothed cats' teeth were stronger relative to the bite force than those of modern "big cats".^[9] In addition, Smilodon could open its jaws 120 degrees, whereas the lion's gape is limited to 60 degrees.^[10]

It has been suggested that Smilodon's smaller temporalis muscles (controlling much of the bite force) were not used in the killing of prey; rather, Smilodon stretched its jaws around the throat and pressed its canines into the prey with the use of its immense neck and forelimb muscles. The penetration was the result of the neck flexors instead of the jaw muscles, according to this hypothesis.

weekly video

2011-10-22T23:31:00.000+07:00

weekly daily dinosaur: Rhamphorhynchus

2011-10-09T19:05:00.000+07:00

"beak snout", is a genus of long-tailed pterosaurs in the Jurassic period. Less specialized than contemporary, short-tailed pterodactyloid pterosaurs such as Pterodactylus, it had a long tail, stiffened with ligaments, which ended in a characteristic diamond-shaped vane. The jaws of Rhamphorhynchus housed needle-like teeth, which were angled forward, with a curved, sharp, beak-like tip lacking teeth, indicating a diet mainly of fish and insects.

Although fragmentary fossil remains possibly belonging to Rhamphorhynchus have been found in England, Tanzania, and Spain, the best preserved specimens come from the Solnhofen limestone of Bavaria, Germany. Many of these fossils preserve not only the bones but impressions of soft tissues such as wing membranes. Scattered teeth believed to belong to Rhamphorhynchus have been found in Portugal as well.^[1]

http://en.wikipedia.org/wiki/Rhamphorhynchus

weekly video

2011-10-09T12:46:00.000+07:00

weekly mammal: Phorusrhacids

2011-10-09T12:29:00.000+07:00

Phorusrhacids ("Rag-Thieves"), colloquially known as "terror birds" as the larger species were apex predators during the Miocene, were aclade of large carnivorous flightless birds that were the dominant predators in South America during the Cenozoic, 62–2 million years (Ma) ago.^[3] They were roughly 1–3 meters (3–10 feet) tall. Their closest modern-day relatives are believed to be the 80 cm-tall seriemas. Titanis walleri, one of the larger species, is known from Texas and Florida in North America. This makes the phorusrhacids the only known example of large South American predators migrating north during the Great American Interchange (which occurred after the volcanic Isthmus of Panama land bridge rose ca. 3 Ma ago). It was once believed that T. walleri only became extinct around the time of the arrival of humans in North America,^[4] but subsequent datings of Titanis fossils have failed to provide evidence for their survival more recently than 1.8 Ma ago.^[5]

Possible phorusrhacid remains have recently been recovered from the Eocene of Algeria.^[6]

A recently discovered species, Kelenken guillermoi from Middle Miocene some 15 million years ago, discovered in Patagonia in 2006, represents the largest bird skull yet found. The fossil has been described as being a 71 cm (28 in), nearly intact skull. The beak is roughly 46 cm (18 in) long and curves in a hook shape that resembles an eagle's beak. Most species described as phorusrhacid birds were smaller, 60–90 cm (2.0–3.0 ft) tall, but the new fossil belongs to a bird that probably stood about 3 m (9.8 ft) tall. Although scientists cannot be sure, they theorize that the large terror birds were extremely nimble and quick runners able to reach speeds of 48 km/h (30 mph).^[7]

http://en.wikipedia.org/wiki/Phorusrhacidae