Utahraptor

Utahraptor was the largest of a group of lightly-built carnivores, called the dromaeosaurs or "swift lizards". It had large eyes, long grasping hands and powerfully clawed feet. Clearly it was carnivorous, but was distinctive in relying on a wickedly hooked, slashing claw on each foot rather than the jaws and teeth of a typical predator.
Its toe joints were specially enlarged so that its massive claw could be raised upward and backward to avoid damage while running. But when used in attack, its claw flexed forward as the animal kicked out.
To help it balance on one foot while kicking, its tail acted like an acrobat's balancing pole, being stiffened by a sheath of fine bony rods. Swinging in a wide arc its huge 20 cm slashing claw would produce terrible wounds enabling a Utahraptor to cripple and kill animals much larger than itself. The discovery of a number of skeletons of the closely related dromaeosaur, Deinonychus, around the skeleton of a large plant eater suggests that dromaeosaurs may well have hunted in packs.
Utahraptor is known from a well-preserved skeleton found in 1991 in Utah, USA and fragmentary remains from South America. It was up to 6.5m long, 2m high and a weight of almost a tonne!
The dromaeosaur group also included Velociraptor, made famous by Steven Spielberg in "Jurassic Park". For the film, Velociraptor was made twice its actual size, which seemed to be very speculative at the time. However, within a year of the release of the film, a giant dromaeosaur had been found, namely Utahraptor. So life can be stranger than fiction!

Tyrannosaurus rex

Tyrannosaurus was one of the largest of the "lizard-hipped" carnivorous dinosaurs known as theropods. It was a massive two legged with a powerful tail, large head and tiny arms from the late cretaceous.

About 14m long, 5m tall and 5 tonnes!

Its primary weapon was its mouth, with a 1.2 metre long jaw and a 1 metre gape. Curved serrated teeth, longer than a human hand, could be used to puncture an animal's organs, before Tyrannosaurus tore the flesh off. Tyrannosaurus could not chew, so had to swallow its food whole. It could probably gulp up to 70 kilograms in one go. One fossil shows the danger of this - a large carnivore had died swallowing, with two long bones stuck in its gullet.

In the picture above it is attacking the armored dinosaur Edmontonia and in the following one you can spot a flying Quetzalcoatlus and Pleurocoleus as well.

Its tiny two-fingered arms seemed very small, but were believed to have been at least three times as strong as human arms. They were too short to reach its mouth, but were probably used as meat-hooks. There is clear evidence that tyrannosaurs fought one another from tooth-marks left in fossil remains.

The first reasonably complete Tyrannosaurus skeleton was discovered by palaeontologist Barnum Brown in Hell Creek, Montana, in the USA in 1902. Until this find only fragments had been unearthed. In all, over 20 individuals have been found, although, only three have complete skulls. Remains have been discovered from Alberta and Saskatchewan in Canada,to New Mexico, Montana, Texas, Utah, and Wyoming in the USA. Remains have also been found in Mongolia.

But not everything were those remains... Jeff Anders and Tom Koehnlein did it—a CT scan of a Tyrannosaurus rex skull. The 2,000-pound (908-kilogram) head belonging to Sue, the largest and most complete T. rex ever found, would never fit on an ordinary medical scanner. So Sue went to a Boeing lab in California, where the two engineers spent some 500 hours in 1998 x-raying coin-thin portions of the skull—slicing digitally instead of destructively. “We’d never done anything like it before,” said Koehnlein. The result: new insight into Sue’s senses.

“A Dinosaur Named Sue” appeared in the June 1999 issue of NATIONAL GEOGRAPHIC.

By the way, Sue also knew how to enjoy herself.

Torosaurus

Torosaurus was a 8m long and 7 tonnes "bird-hipped" cretaceous dinosaur from the group known as the horn-faced dinosaurs or ceratopsians. It was a large sociable herbivore with a strong beak, able to handle the toughest vegetation including small branches. It had powerful legs that were short at the front and longer at the back, which gave it a very stable posture.
Its enormous 2.6 metre crested skull is the largest known from any land animal. It had two brow horns, a short nose horn and a long-frilled crest giving it a fierce appearance. Many theories have been proposed for its use: originally it was thought that it was primarily used for defence or to house massive muscles for eating tough vegetation.
However, the presence of two large holes in its crest have led palaeontologists to believe that it was used for sexual display and to intimidate opponents. The holes would have been covered by stretched skin creating vivid eye-spots when flushed with blood.
Torosaurus was discovered by John B. Hatcher and named in 1891. Evidence for the Torosaurus includes several partial skulls and incomplete skeletons from Alberta and Saskatchewan in Canada and states in the USA, including Montana, Texas, Utah, and Wyoming. In all, 21 skeleton fragments have been identified as Torosaurus, but there is debate amongst paleontologists as to how many species of Torosaurus existed.

Tanystropheus

was a 6 metre long reptile from the Middle Triassic period. The main feature that stands out about this animal is its extremely elongated neck 3 meters (10 ft) long, longer than its body and tail combined.

I dunno why it was confused once with a pterosaur!

Tanystropheus is considered to have been fish-eater, due to the presence of a long, narrow snout sporting sharp intelocking teeth.

However some scientists have argued that such a disproportionate neck would have placed Tanystropheus' center of gravity in front of its arms- causing it to fall flat on its face every time its neck stuck out. So for them it was kinda arboreal!

But it seems that it was just an amphibian (!) reptile!

Supersaurus

I love this picture!

Tenontosaurus and Hypsilophodonts

Tenontosaurus was a member of the iguanodon clan.
Hypsi{s teeth were curious! do you know why?

Tarbosaurus

At a lofty five metres tall and a whopping five tonnes in weight, Tarbosaurus was monstrously large. But Tarbosaurus was relatively light on its feet, despite its size. It probably used its long, powerful legs to sprint across the Mongolian desert after prey.
There were not many dinosaurs around at the time capable of taking on Tarbosaurus. The dinosaur may have stalked the lightly wooded areas on the desert outskirts, searching for vulnerable, lone dinosaurs or lying in wait for other animals to approach it.
Once a suitable victim had been spotted, Tarbosaurus would have made an explosive run for its prey. The dinosaur may have tried to exhaust its prey before using its powerful jaws to sink its sharp teeth into the other animal.
Tarbosaurus' victims could at least take comfort in the knowledge that death would be swift. Tarbosaurus would then dissect the corpse, removing as much meat as possible before leaving the body to other scavengers.
Tarbosaurus may have hunted dinosaurs that were almost as large as itself (such as Saurolophus) although gigantic dinosaurs such as Therizinosaurus may have been too large for it to handle.
The metabolism of Tarbosaurus means that it probably only needed to eat once every two or three weeks although, like any animal, it would have taken advantage of any opportunity that came its way.
Tarbosaurus had a good sense of smell, which may have played a role in locating its food or in detecting the scent of a rival or potential mate. It may have roamed over a moderately wide area in search of food or a sexual partner.
Like, Tyrannosaurus, its American cousin, Tarbosaurus would have been a dinosaur to avoid in the Mongolian Late Cretaceous.

The Evidence

Tarbosaurus was first described in 1955 after the remains of at least seven individuals were recovered in China by a Russian fossil collecting expedition. Since then, the bones from about thirty individuals have been found.
The skeleton of Tarbosaurus is near identical to that of Tyrannosaurus and some paleontologists have argued as to whether Tarbosaurus should be renamed as a species of Tyrannosaurus. However, there are sufficient differences between the skulls of these two animals to warrant giving them two separate names.
In Mongolia the remains of Tarbosaurus are commonly found in rocks that were laid down in wet environments with lots of vegetation, suggesting that it preferred to live and hunt in wooded regions. However, Tarbosaurus remains have also been recovered from the fossilised sand dunes of Mongolia's Nemegt Formation suggesting that it was capable of surviving in drier and arid desert environments.
From the outset it was obvious to scientists that Tarbosaurus would have been an active meat-eating dinosaur. Tarbosaurus' sense of smell was especially well-developed.
Whilst this would undoubtedly have helped it find its prey, it has also been suggested that both Tyrannosaurus and Tarbosaurus were scavengers and may have used their sense of smell to find rotting carcasses.
Like many modern predators, it is probable that Tarbosaurus would have both hunted and scavenged, a strategy that would be necessary in a barren desert world where at times food would be extremely scarce.

Stegosaurus

Meaning : Covered lizard
Diet : Herbivore - low level ferns
Size : Up to 12 metres long
Weight : Up to 7 tonnes
Fossil Finds: USA & Europe (Update: year 2006)

Stegosaurus was a herbivorous "bird-hipped" dinosaur, which cropped vegetation with its powerful beaked mouth. It had four sturdy legs - its back ones were considerably longer and straighter than its front ones.
An eyecatching row of large pointed plates ran down its back. Their role is unclear. It was thought that they were used as armour, or as a form of heat control. Palaeontologists now believe that they were used for display - both for putting off attackers and for attracting a mate.
For defence it used its formidable tail - a short and muscular weapon equipped with four 1 metre long spikes. It also had a series of bones under its neck that acted like chain mail to protect its throat.
The first Stegosaurus fossil was discovered in Colorado by M. P. Felch in 1877. Stegosaur fossils are widely distributed from the United States to China showing how successful this dinosaur group was.
There are many different types of stegosaur, of which Stegosaurus is the largest. Fossils from three different species of Stegosaurus have now been identified from the Morrison Formation in the western USA. These finds have included complete skeletons and juveniles.

Saurolophus

These 11-12 meters long crested animals would have been a sight to behold as they travelled in numbers across the Nemegt desert. Feeding on soft foliage like leaves meant Saurolophus was constantly moving on from one grazing area to another.
Although it normally walked on four legs, Saurolophus would have raised itself onto two feet in order to eat from higher branches. After stripping the leaves from these branches, it used specialised teeth to pulverise the vegetable matter before swallowing it.
A fully-grown Saurolophus would have been one of the largest dinosaurs in the Nemegt Desert (5 tonnes), rivalling both Tarbosaurus and Therizinosaurus in size and weight. They may have moved in small herds or in groups of a dozen or so individuals. At certain times of the year, Saurolophus may have gathered together in order to nest in large colonies.
A need for a constant supply of vegetation would have kept Saurolophus from the most arid regions of the Nemegt Desert.
Saurolophus had few methods of defence. It was slow moving and had no claws or sharp teeth to fight off predators. But its gigantic size was in itself a very effective deterrent. Only the largest predators, such as Tarbosaurus, would have dared tackle an adult Saurolophus.

The Evidence

The first Saurolophus skeleton was uncovered in Alberta, Canada, in 1912. Many more finds followed in the region afterwards. Then, in 1946, Russian palaeontologist Ivan Efremov recovered seven near-complete Saurolophus skeletons at a location called Altan Ula in Mongolia. This suggests that there may have been a link between Canada and Asia in the Late Cretaceous period. The recovery of these skeletons has since led local tribesmen to call Altan Ula the 'Dragons' Tomb'.
Saurolophus was part of the hadrosaur group of dinosaurs. At 12 metres in length and 5 tonnes in weight, it would have been one of the largest dinosaurs found in the Nemegt. It was a herbivore and, like other hadrosaurs, had specialised teeth that could grind even the toughest vegetation to pulp. These teeth were arranged in multiple layers. An adult Saurolophus might have had over 1000 teeth in its mouth.
Proof of its diet comes from a well-preserved specimen of Edmontosaurus (to which Saurolophus is related) from North America. In its stomach were fossils of conifer plants, seeds and deciduous leaves showing that these animals were not fussy eaters.
Saurolophus skeletons are more commonly associated with the wetter, more vegetated parts of the Nemegt Desert and their remains are only rarely found in the sand dune areas themselves.
The discovery of several Saurolophus at Altan Ula has led to speculation that these dinosaurs may have travelled in large social groups. There is even evidence that they may have nested in vast colonies and that parents brought up their young in the nest, much as modern birds do.
Living in large groups offers protection to animals like Saurolophus - and they may have needed it. In 1992, a Saurolophus skeleton was discovered which had the foot of the giant meat-eating dinosaur Tarbosaurus attached to it. Scientists cannot say for certain that the Tarbosaurus was in the middle of attacking the Saurolophus, but Tarbosaurus would certainly have been capable of taking on this large dinosaur.

Rhamphorhynchus

Rhamphorhynchus was a primitive type of flying reptile with wings up to 1 metre long. These were made of skin stretched between an elongated finger from its hand, down to its ankle.
It had a long straight tail (20 cm) stiffened with ligaments which ended in a diamond-shaped rudder. It is believed that one of the ways Rhamphorhynchus hunted was by dragging its beak in the water . When it came into contact with prey, it would snap its needle-sharp teeth shut, and toss the food into it's throat pouch, a structure that has actually been preserved in some rare fossils.
Rhamphorhynchus fossils have been recovered from Jurassic marine clays in southern England but the finest specimens come from the Solnhofen quarry in Bavaria, southern Germany. The fine-grained limestone of this famous quarry has yielded numerous beautifully preserved remains of Rhamphorhynchus. Many of these fossils not only preserve the bones but also show impressions of soft tissues such as the wings and tail.

Quetzalcoatlus

Quetzalcoatlus was a huge pterosaur with a wingspan of up to 13 metres - the largest flying creature of all time. It is the last known pterosaur and survived to the very end of the Cretaceous period.
Despite its huge size, its skeleton was lightly built and the whole animal probably weighed no more than 100 kilograms. It was a good soarer - certainly able to cover large distances. Its neck was extremely long, its slender jaws were toothless and its head was topped by a long, bony crest.
Douglas Lawson was the first to find a Quetzalcoatlus fossil, at Big Bend National Park in Texas, USA. Unlike most other pterosaur fossils these remains were not found in marine strata but in the sand and silt of a large river's flood plain. This raised questions about how it lived.
The fact that Quetzalcoatlus had a long neck, and that it can soar 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.
Lawson named the pterosaur after the Aztec's feathered-serpent god, Quetzalcoatl.

Pterosaurs

As you can see dinosaurs weren't alone, there were mosasaurs and pterosaurs.

Reptiles that ruled the skies for millions of years.

They had great diversity.

Pteranodon

120 to 75 million years ago
Early to Late Cretaceous period

Fossil Finds: PERU, North America, Europe, Australia, Japan
Pteranodon "Toothless Wing" was a 7m large and graceful pterosaur that would have used rising air currents, or 'thermals' to soar into the air. Pteranodon was designed to live in the air and would have been ungainly and awkward on land, putting it at risk from predators. For this reason, it probably only landed to mate, nest or rest.

Pteranodon was primarily a fish-eater and would have spent much of its time circling estuaries, lakes and seas. When it attacked, it swooped down towards the water's surface, dipped its beak in and grabbed a fish before swallowing it whole.

The distinctive head crest on Pteranodon was actually only found on the males and was probably used during mating displays or to intimidate male rivals. Pteranodon would have laid eggs and made nests much as many modern sea birds do. They would also have needed to provide food for their hatchlings, flying out to sea to catch fish and then bringing them back to the nest.

When in flight, an adult Pteranodon would have had few enemies. But the same would not have been true on land, where its lack of mobility would have made it vulnerable to the attentions of predators and rivals.

Being a specialised fish hunter, any injury to Pteranodon, especially on its delicate wings, would have presented a serious threat to its well-being. Any Pteranodon that found itself unable to take-off would be doomed to either starve to death or to be caught and eaten by a predator such as Giganotosaurus.
The Evidence

Pteranodon had a massive wingspan of eight metres. But its body weight would have been very low indeed, perhaps around 20 kg. This would have allowed it to glide for hours at a time, covering vast distances whilst expending only a minimal amount of energy. In North America, Pteranodon fossils have been discovered in rocks which would have been deposited many kilometres out to sea indicating their travelling ability. The beak of Pteranodon was toothless and was probably used to catch fish from near the surface of the ocean, perhaps scooping them out of the sea and swallowing them whole as a modern pelican does. In order to hunt effectively, Pteranodon had evolved good eyesight and a reasonably large brain.
The first Pteranodon skeleton was discovered in Kansas in 1876 and was later studied and named by palaeontologist Othniel C. Marsh. Since then, hundreds of Pteranodon skeletons have been discovered from locations across the world. There is still a debate between scientists as to which exact physical characteristics define Pteranodon.

One of the greatest mysteries about Pteranodon is the function of its large head crest. Many theories have been put forward as to the purpose of this crest. One proposes that it may have used it as a rudder or as a means of slowing the animal down. However, tests using Pteranodon models in wind tunnels suggest that to use the crest in this manner would have put undue stress on the neck.

Instead, there is now evidence that juvenile and female Pteranodon had much smaller crests than the males. This suggests that the real purpose of the crest was sexual and that it was probably used by male Pteranodon to try and impress females of the species.

Polacanthus

Polacanthus was a nodosaur, a type of 'bird-hipped' dinosaur from the cretaceous. It sported a thick coat of bony armour plates that covered its rump. Evenly spaced rows of fierce spikes ran along its sides and shoulders. It was closely related to both the stegosaurs and ankylosaurs. All of these relied on armour or spines rather than fleetness of foot as defence against predators. Fossil remains show that it was a squat, four-legged 4m length and 1.5m high herbivore that ate ground vegetation. It is only known about from three fragmentary skeletons and many armoured plates. These have been found in southern England, particularly on the Isle of Wight.

Sea Monsters - Pliosaurs

Near the end of the Cretaceous period most of the marine reptiles such as the pliosaurs became extinct.

Plateosaurus

Plateosaurus evolved in the Late Triassic period and lived through to the Early Jurassic period. It was the first of the giant dinosaur herbivores, growing to around 9 metres long and 3-4 metres high. It had a long tail, long hind limbs, and a small head at the end of a fairly long neck. It had leaf-shaped teeth, and a beak-like jaw. Plateosaurus belonged to a group known as the prosauropods and was a relative - though not an ancestor - of the gigantic sauropods of the Jurassic and Cretaceous. Until their appearance all herbivores had been squat, short-necked animals incapable of reaching high foliage. Plateosaurus and the other prosauropods were the first dinosaur group to feed exclusively on plant-matter. Although Plateosaurus walked on four legs, palaeontologists believe that it could rear up on its hind legs and use its powerful clawed hands to pull in succulent branches. It was the first animal to evolve the ability to feed on relatively high vegetation. Many fossils of these dinosaurs have been found throughout Europe and several species have been identified. The abundance of Plateosaurus fossils at some localities has prompted the suggestion that they lived in herds and even that they migrated to avoid seasonal droughts.

Placerias, Coelophysis, Phytosaur and Metoposaur

Just another beautiful triassic landscape.
I think this picture belongs to Karen.

Placerias

Placerias was a 1 tonne sturdy animal with tusks for rooting through the soil in search of a range of vegetation, and a beak for uprooting plants during the Triassic. A low-slung, powerful animal (3.5 meters long) resembling a hippopotamus, Placerias was not a dinosaur, but a dicynodont or "two-tooth dog". It was so called because it had toothless jaw margins with only the two canine teeth, near the front. Dicynodonts are therapsids, or mammal-like reptiles, a group that includes the ancestors of modern mammals. The best fossil find was at the Petrified Forest at St Johns, Arizona in the USA, where forty individuals were identified. Some palaeontologists believe there is evidence that Placerias lived in a seasonal environment. Wear patterns on the tusks of other dicynodonts show alternate deep grooves and a smoother polishing effect. In the dry season they would have dug hard earth, which scarred the tusks. In the wet season, the ground would be wet and silty, helping to polish them.

Peteinosaurus

Peteinosaurus was a flying reptile - one of the first known pterosaurs from the Triassic period. From fossil finds palaeontologists know that its ability to fly was already well-developed. It had a very light-boned skeleton (100g!). Its wings consisted of skin stretched between an elongated finger on its hand, and its foot. They were attached to the length of its body and thigh. Peteinosaurus is one of the earliest vertebrates to show evidence of flying rather than gliding. It had a long straight tail, up to about 20 cms long (and a 60 cm wingspan), which it used for precise manoeuvring. This was made of vertebrae, strengthened with bone-like fibres. It had even-sized, sharp, cone-like teeth. It is most likely that it ate insects which it caught on the wing. Beautifully preserved Peteinosaurus fossils were discovered in rocks dating from the Triassic period, near Cene, in the Italian Alps. Pterosaurs are largely considered to be close cousins of the dinosaurs, but the absence of transitional forms means this is not entirely certain.

Dinosaurios sudamericanos

Acá una familia de la Patagonia, zona sudamericana rica en fósiles.

Parasaurolophus

Parasaurolophus was a hadrosaurid (duck-billed) dinosaur from the Upper Cretaceous Period (about 76-65 million years ago) of North America. Its name means 'near crested lizard', which refers to another hadrosaurid, Saurolophus, discovered before Parasaurolophus. Parasaurolophus were about 10 m (33 ft) long, 5 m (16 ft) high and weighed around 3500 kg (7,700 lb). Like other hadrosaurs, they could alternate between two legs and four, probably preferring a quadrupedal gait while they foraged for food and assuming a bipedal mode for faster running. They were fully terrestrial animals, as evidenced by footprints.

Oviraptor 72 mya

Once upon a time there was a dinosaur considered an evil egg robber!

... but cretaceous nesting grounds showed something different!

THEY WERE GOOD MOMMIES!

Othnielia from Late Jurassic

(oth-NEE-lee-ah)
Named after Othniel Charles Marsh, the famous palaeontologist.
Ornithopod, herbivore, up to 4 metres long and up to 20 kilograms
From the USA (Morrison Formation, Colorado, Wyoming, Utah)
Othnielia was a relatively large herbivorous biped, related to Leaellynasaura and Dryosaurus. So far, only a couple of well-preserved partial skeletons are known plus scattered bones and teeth. Othnielia used its horny beak to crop low-growing vegetation and its stiff tail acted as a counterbalance when running.

Ornitholestes

Seems like that horn in its face was a mistake! lol

Ornithocheirus

Ornithocheirus was a large (12m wingspan) pterosaur with a long slender skull and often a bony crest on its snout. It had sharp teeth set in a long tapering jaw designed for catching fish.

At the beginning of the Cretaceous period, short-tailed pterosaurs like Ornithocheirus replaced the earlier long-tailed varieties. They also started to grow much larger.

Ornithocheirus had the wing area of a small aeroplane, yet because of its hollow bones, its body probably weighed less than a human. Its wings were made of skin stretched between an enormous elongated finger, and its ankle. They were joined to the rest of its body and its legs. Using rising air currents, or "thermals", Ornithocheirus may have been able to fly hundreds of kilometres (from England to South America) without flapping its wings. This could account for the world wide distribution of its fossil remains.

The first fossils of Ornithocheirus were found in the Wealden Formation in Sussex, England in 1827. They were not formally described as Ornithocheirus until 1869. Despite the fact that only partial remains have been discovered, 36 species have been identified from the assortment of over 1000 bones. Most of these have come from the Cambridge Greensand which is a Late Cretaceous rock unit found near Cambridge, England.

Ornitocheirus

master of the skies!