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Pachycephalosaurus

Tuesday, December 6, 2016

Pachycephalosaurus

Pachycephalosaurus (meaning “thick-headed lizard,”) is a genus of pachycephalosaurid dinosaurs. The type species, P. wyomingensis, is the only known species. It lived during the Late Cretaceous Period (Maastrichtian stage) of what is now North America. Remains have been excavated in Montana, South Dakota, and Wyoming. It was an herbivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, though more complete fossils have been found in recent years. Pachycephalosaurus was one of the last non-avian dinosaurs before the Cretaceous–Paleogene extinction event. Another dinosaur, Tylosteus of western North America, has been synonymized with Pachycephalosaurus.

Size comparison of an adult P. wyomingensis (green), potential growth stages, and a human. Author: Matt Martyniuk

Like other pachycephalosaurids, Pachycephalosaurus was a bipedal herbivore with an extremely thick skull roof. It possessed long hindlimbs and small forelimbs. Pachycephalosaurus is the largest known pachycephalosaur.

The thick skull domes of Pachycephalosaurus and related genera gave rise to the hypothesis that pachycephalosaurs used their skulls in intra-species combat. This hypothesis has been disputed in recent years.

Pachycephalosaurus is the last, largest, and most famous member of the Pachycephalosauria, or thick-headed dinosaurs. In the 1970s paleontologist Peter Galton proposed that male pachycephalosaurs used their dome heads as battering rams, like Bighorn sheep. The idea caught the public’s imagination, and two individuals are seen doing this in The Lost World: Jurassic Park (of course, these are genetically engineered dinosaurs and not necessarily exactly the same ones that lived 70 million years ago!). But by the 1990s, scientists began to question Galton’s head butting theory. It was pointed out that animals who do butt heads have a wide surface area where the heads come into contact to prevent “head slippage.” This happens when two animals butt heads at high speed and do not hit straight on. The risk breaking their necks when their heads suddenly snap to one side. Pachycephalosaurus has a domed, or rounded, head, which would minimize surface contact and therefore increase the risk of head slippage. This throws doubt on the idea of any high speed head-butting between pachycephalosaurs, but it does not exclude “head-pushing” of “head-ramming” against non-pachycephalosaurs.

The skull, which was almost 2 feet (60 cm) long, was nearly 8 inches (20 cm) thick at the central part of the dome. Pachycephalosaurus had triangular teeth with coarse serrations along the edges for shredding tough plant matter.

Pachycephalosaurus skeletons. Credit: Kabacchi

Nearly all Pachycephalosaurus fossils have been recovered from the Lance Formation and Hell Creek Formation of the western United States. Pachycephalosaurus possibly co-existed alongside additional pachycephalosaur species of the genera SphaerotholusDracorex and Stygimoloch, though these may represent juveniles of Pachycephalosaurus itself, though Sphaerotholus is regarded as a valid species. Other dinosaurs that shared its time and place include Thescelosaurus, the hadrosaurid Edmontosaurus and a possible species of Parasaurolophusceratopsids like TriceratopsTorosaurusNedoceratopsTatankaceratops and Leptoceratops

ankylosaurids Ankylosaurus, nodosaurids Denversaurus and Edmontonia, and the theropods AcheroraptorDakotaraptorOrnithomimusStruthiomimusAnzuLeptorhynchosTroodon

PectinodonParonychodonRichardoestesia and Tyrannosaurus.

Could You Outrun a Tyrannosaurus Rex?

Tuesday, December 6, 2016

Tyrannosaur footprints is giving researchers new insight into the speed of the prehistoric beasts.

Could you outrun a T. rex? Research on the rare Wyoming discovery has determined that the tyrannosaur was traveling roughly 2.8 to 5 miles per hour, slower than an average human runs. But, the researchers warn that these footprints aren’t nearly representative of a T. rex’s peak speed.

  • Fossilized footprints reveal a tyrannosaur traveling between 2.8 to 5 mph

  • This is slower than an average human runs, at 11 mph over short distance

  • Still, researchers assert prints only represent walk through mud, not a run 

  • Decades of debate reveal estimates between 10 and 45 mph for top speed

Graphic by Stephanie Fox

QUICK ANSWER

A T. rex could have run faster than an average human at top speed, but there is a chance that a human could outrun a T. rex. We can never fully know how fast the Tyrannosaurus rex ran, but scientists at the University of Manchester in England have come up with animated computer models based on fossils and estimated muscle mass that have helped them compute the probable top speeds of many dinosaurs. The Tyrannosaurus rex is nowhere near the fastest, topping out at around 18 mph. The fastest dinosaur they computed was the Compsognathus, which ran about 40 mph.

FULL ANSWER

Usain Bolt, the fastest man on Earth, set a world record for running 27.79 mph in the 100 meter sprint in 2009. He is not likely to get eaten by a Tyrannosaurus rex in the near future, but let’s look at a more average human. Running a four minute mile is the standard of all male professional middle distance runners, and translates to a speed of 15 mph. That’s perhaps a little faster than some of us would run a mile, but if we were running for our life it’s a pretty decent estimate.

If speed alone was a factor, a T. rex would win. However, it would take time for a dinosaur of that mass to get started, and it would not reach its top speed of 18 mph as soon as it would take a human to reach their top speed. Additionally, a Tyrannosaurus Rex is not as agile as a human and would likely get exhausted quickly. So your chances of outrunning a Tyrannosaurus rex are good if the distance to safety is short, or if you could weave and avoid him until he gets exhausted.

10 Prehistoric Creatures We’d Love to Have in a Zoo

Monday, December 5, 2016

10 Dinosaur Species We’d Love to Have in a Zoo

If I’d list down all their species then that would be more than a hundred thousand, so diverse was the kingdom of this terrestrial reptile. Since quite enough we have been conjured up by the aura of that one mosquito bite which could bring that vogue extinct race back to the world’s terrene. So what if it actually happens? would we risk it or not i don’t know so avoiding that dispute  and taking you to those ten esteemed dinosaurs out of way so many that people fancy and would like to have in that kind of park.

10. Sinosauropteryx (The Most Colorful Dinosaur)

Wired

There have been a number of dinosaurs with feathers but some were not even recognizable. Sinosauropteryx is the first genus of non-avian dinosaur found with the fossilized impressions of feathers, as well as the first non-avian dinosaur where coloration has been determined. It lived in China during the early Cretaceous period and was a close relative of Compsognathus (the smallest dinosaurs ever). The remarkably well-preserved fossils show that Sinosauropteryx was covered with a furry down of very simple feathers — though some contention arose with an alternative interpretation of the filamentous impression as collagen fiber remains. These filaments consisted of a simple two-branched structure, roughly similar to the secondarily primitive feathers of the modern kiwi. Sinosauropteryx is distinguished from other small dinosaurs by several features, including having a skull longer than its upper leg bone (femur) and very short, stout forelimbs, with the arms being only 30% the length of the legs.

9. Liopleurodon (Marine Dinosaur)

Nekros00

Liopleurodon is only on this list which is not scientifically classified as a dinosaur but in popular culture, it is referred to as so because of their co-existence with dinosaurs in the Jurassic era. Liopleurodon fossils have been found mainly in England and France, with one younger species known from Russia. Four strong paddle-like limbs suggest that Liopleurodon was a powerful swimmer. It provides very good acceleration – a desirable trait in an ambush predator by  scanning the water with its nostrils to ascertain the source of certain smells. It’s size was around  34 ft long. In 1999, Liopleurodon was featured in an episode the BBC television series Walking with Dinosaurs. In the programme, Liopleurodon was depicted attacking and devouring the theropod dinosaur, before becoming beached during a typhoon and suffocating under its own weight. The depiction of Liopleurodon leaping onto the land in order to catch land-based prey is entirely speculative.

8. Ankylosaurus (The Armored Dinosaur)

Dino News

Ankylosaurus is often considered the archetypal armored dinosaur. Its well-known features are – the heavily-armored body and massive bony tail club – but Ankylosaurus was the largest known member of the family. In comparison with modern land animals the adult Ankylosaurus was very large. Some scientists have estimated a length of 30 ft. The body shape was low-slung and quite wide. Ankylosaurus was quadrupedal, with the hind limbs longer than the forelimbs. Ankylosaurus was herbivorous, with small, leaf-shaped teeth suitable for cropping vegetation. These teeth were smaller, relative to the body size. Bones in the skull and other parts of the body were fused to increase their strength. The most obvious feature of Ankylosaurus is its armor, consisting of massive knobs and plates of bone, known as osteoderms or scutes, embedded in the skin. The plates were aligned in regular horizontal rows down the animal’s neck, back, and hips, with the many smaller nodules protecting the areas between the large plates. The famous tail club of Ankylosaurus was also composed of several large osteoderms, which were fused. It allowed great force to be transmitted to the end of the tail when it was swung. It seems to have been an active defensive weapon, capable of producing enough of a devastating impact to break the bones of an assailant.

7. Triceratops (Last Dinosaur before Mass Extinction)

Wiki Media

It was one of the last dinosaur genera to appear before the great extinction. Bearing a large bony frill and three horns on its large four-legged body, and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs. Although it shared the landscape with and was preyed upon by the fearsome Tyrannosaurus, it is unclear whether the two did battle in the manner often depicted in museum displays and popular images. The function of their frills and three distinctive facial horns has long inspired debate. Although traditionally viewed as defensive weapons against predators, the latest theories claim that it is more probable that these features were used in courtship and dominance displays, much like the antlers and horns of modern reindeer, mountain goats, or rhinoceros beetles.

6. Stegosaurus (Spiky Dinosaur)

Stegosaur by Sergei Krasovskiy

Due to its distinctive tail spikes and plates, Stegosaurus is one of the most recognizable dinosaurs. They lived some 150 to 145 million years ago, in an environment and time dominated by the giants. A large, heavily built, herbivorous quadruped, Stegosaurus had a distinctive and unusual posture, with a heavily rounded back, short forelimbs, head held low to the ground and a stiffened tail held high in the air. Its array of plates and spikes has been the subject of much speculation. The spikes were most likely used for defense, while the plates have also been proposed as a defensive mechanism, as well as having display and thermoregulatory (heat control) functions. Stegosaurus was the largest of all the stegosaurians but still roughly bus-sized. Averaging around 30 ft long and 14 fttall, the quadrupedal Stegosaurus is one of the most easily identifiable dinosaurs, due to the distinctive double row of kite-shaped plates rising vertically along its rounded back and the two pairs of long spikes extending horizontally near the end of its tail. Although a large animal, it was dwarfed by its contemporaries, the giant sauropods. Some form of armor appears to have been necessary, as it coexisted with large predatory dinosaurs.

5. Archaeopteryx (Only Avian Dinosaur)

Image Source: Unknown

Archaeopteryx, from the late Jurassic Period, may be the earliest known theropod dinosaur which may have had the capability of powered flight. If Archaeopteryx is defined as an avian, then there are few non-avian avialans. Avialae is the only clade of dinosaurs containing their only living representatives, birds, and the most immediate extinct relatives of birds.  Similar in size and shape to a European Magpie, Archaeopteryx could grow to about 1 metre  in length. Despite its small size, broad wings, and inferred ability to fly or glide, Archaeopteryx has more in common with small theropod dinosaurs than it does with modern birds. In particular, it shares the following features with the deinonychosaurs (dromaeosaurs and troodontids): jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes (“killing claw”), feathers (which also suggest homeothermy), and various skeletal features. The features above make Archaeopteryx a clear candidate for a transitional fossil between dinosaurs and birds. Thus, Archaeopteryx also plays an important role not only in the study of the origin of birds but in the study of dinosaurs.

4. Compsognathus (Smallest Known Dinosaur)

Blass

The animal was the size of a turkey and could weigh as less as 0.26g and lived around 150 million years ago in what is now Europe. It is the smallest known dinosaur. Compsognathus is one of the few dinosaurs for which the diet is known with certainty: the remains of small, agile lizards were found preserved in the bellies of  specimens. Although not recognized as such at the time of its discovery, Compsognathus is the first dinosaur known from a reasonably complete skeleton and the smallest and the closest supposed relative of the early bird Archaeopteryx. Thus, the genus is one of the few dinosaur genera to be well known outside of paleontological circles.

3. Amphicoelias fragillimus (Largest Known Dinosaur)

Amphicoelias herd by Raul Martin

A. fragillimus is the largest and heaviest dinosaur ever discovered. A. fragillimus may have been the longest known vertebrate at 40–60 meters (131–196 ft) in length, and may have had a mass of up to 122 metric tons. Whatever evolutionary pressure caused large size was present from the early origins of the group. Carpenter cited several studies of giant mammalian herbivores, such as elephants and rhinoceros, which showed that larger size in plant-eating animals leads to greater efficiency in digesting food. Since larger animals have longer digestive systems, food is kept in digestion for significantly longer periods of time, allowing large animals to survive on lower-quality food sources. This is especially true of animals with a large number of ‘fermentation chambers’ along the intestine which allow microbes to accumulate and ferment plant material, aiding digestion.

2. Velociraptor (Raptor)

Ning

Velociraptor (commonly shortened to ‘raptor’) is one of the dinosaur genera most familiar to the general public that existed approximately 75 to 71 million years ago. Velociraptor was a mid-sized dromaeosaurid, with adults measuring up to 6.8 ft long, 1.6 ft high at the hip, and weighing up to 15 kg. The skull, which grew up to 9.8 in long, was uniquely up-curved, concave on the upper surface and convex on the lower. The jaws were lined with 26–28 widely spaced teeth on each side, each more strongly serrated on the back edge than the front—possibly an adaptation that improved its ability to catch and hold fast-moving prey. It was a bipedal, feathered carnivore with a long, stiffened tail and an enlarged sickle-shaped claw on each hindfoot, which is thought to have been used to kill its prey. Velociraptor can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout.

1. Tyrannosaurus rex

Wiki Media

T-Rex, yes we can’t forget the dinosaur king for obvious reasons. It was among the last non-avian dinosaurs to exist. It lived throughout what is now western North America, 7 to 65.5 million years ago. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods (a dinosaur subclassification) rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring up to 42 ft in length, up to 13 ft tall at the hips, and up to 6.8 metric tons (7.5 short tons) in weight. By far the largest carnivore in its environment, Tyrannosaurus rex was an apex predator.

Runner Ups:

Brachiosaurus (a well known specie known for it’s largest size but new discoveries negated that claim and we had to chose only 1 for our zoo for the big size)
Parasaurolophus (Duck Billed Dinosaur)
Pentaceratops (Triceratops cousin with 5 horns and largest dino skull)

Source: www.SmashingLists.com

10 Interesting Facts About Styracosaurus

Monday, December 5, 2016

Raúl Martín: Styracosaurus

1. INDIVIDUALS HAD SLIGHTLY DIFFERENT FRILL SPIKES.

Also known as “parietal horns,” the relative size of these pointy structures varied noticeably between Styracosaurus specimens.

2. STYRACOSAURUS PROBABLY USED A DIFFERENT FIGHTING STYLE THAN TRICERATOPSDID.

Wikimedia Commons

In a 2009 effort to shed some light on dinosaurian combat, a paleontological team compared several skulls from Centrosaurus (pictured on the left) and the famed Triceratops. Scars consistent with locked-horn showdowns are, it turns out, quite common on Triceratops heads, but relatively rare in Centrosaurus remains. Perhaps this is because the latter herbivore—like its close cousin Styracosaurus—lacked formidable horns above its eyes and probably had to find other means of clashing with rivals.

“Possibly Centrosaurus wasn’t using its horns for fighting,” says Dr. Andrew Farke (who helped execute this study), “or, if it was fighting, it was concentrating its energies on parts away from the skull, like maybe flank-butting or something like that.”

3. STYRACOSAURUS APPEARS IN THE WEIRDEST WESTERN EVER MADE.

The Valley of Gwangi (1969)

Cowboys wrangle stop-motion dinosaurs in Ray Harryhausen’s epic creature feature The Valley of Gwangi (1969).  At one point, predatory “Gwangi” (whose design was loosely based on T. rex and Allosaurus) takes down an enraged Styracosauruswith some help from a spear-toting horseman.

4. …BUT WAS CUT FROM KING KONG (1933).

Styracosaurus | King Kong Wiki

Though animator Willis O’Brien had shot a thrilling action sequence with his poseable Styracosaurus model, this scene wound up getting scrapped. Fortunately, when the hasty sequel Son of Kong (1933) was churned out less than a year later, “Obie’s” Styracosaurus finally secured some screen time.

5. SCIENTISTS HAVE BEEN DIVVYING UP STYRACOSAURUS.

Rubeosaurus ovatus

What’s in a (scientific) name? Clarity, for starters. Once upon a time, Styracosaurus included three recognized species:  S. albertensis, S. parksi, and S. ovatus. In 2007, though this dino got a classification makeover, with S. albertensis and S. parksibeing merged into a single species thanks to their virtually indistinguishable anatomy. Meanwhile, S. ovatus was placed within an entirely new genus and is now called Rubeosaurus ovatus.

6. STYRACOSAURUS’ NOSE HORN WAS SHORTER THAN MOST PEOPLE THINK.

When studying fossils for a living, incomplete specimens can be the bane of your existence, and Styracosaurus’ distinctive nose horn falls into this category: Most of what we know about this nasal apparatus is based on fragmentary fossils. Though it’s traditionally been assumed to have been around 20 inches long, a closer examination reveals that the horn was around half that length (and possibly blunt-tipped).

7. SOME HAVE SAID THAT STYRACOSAURUS HAD ABSURDLY-HUGE JAW MUSCLES.

Model of Styracosaurus in Bałtow Jurassic Park, Bałtów, Poland

The flashy frills of ceratopsians (horned dinos like Styracosaurus and Triceratops) have inspired much debate over the years. Paleontologists Richard Swann Lull and John McLoughlin independently proposed a radical explanation about their function: Perhaps these huge, bony structures were nothing but attachment anchors for the creatures’ (presumably gigantic) jaw muscles. This idea holds that the frill was buried in flesh and bound to the dinosaurs’ necks and shoulders.

Today, most experts currently believe these frills were predominantly display-oriented features. However, there’s no doubt that ceratopsians packed some powerful bites; for more info, check out this entertaining write-up.

8. STYRACOSAURUS BELONGED TO A SUPER-ORNAMENTED SUBFAMILY.

The centrosaurinae is a group of ceratopsians whose members lacked large horns above their eyes, had pronounced nose horns instead, and rocked short, well-decorated frills.

9. CRUSHED SKULLS DISTORTED MANY EARLY STYRACOSAURUSILLUSTRATIONS.

LEFT: an outdated (and rather ugly) restoration of Styracosaurus based on the crushed skull, with the incline of the snout and frill shown in red along the skull roof line and the nostril line. Also, notice how the dino is straining to cover its back with that frill like a turtle retracting its head into its shell. Yet the very fact that the frill was mostly filled with soft tissue made it useless as armor - it was primarily a display device! I doubt the animal could even hold its neck in such a strained position. The artist is a "C. Douglas", a name which does not ring any bells. Sadly, most dinosaur books show Styracosaurus in a similar "duck-and-cover" position.

Fossilization can be a cruel mistress. One of the world’s most complete Styracosaurus skulls contains a crucial flaw: Its frill has been artificially bent by the elements. This specimen was unearthed in the 1910s and helped scientists understand what the strange animal looked like. Several academic paintings and sketches would be based upon this magnificent fossil. But, unfortunately, geological forces had, over time, unnaturally crushed the dinosaur’s frill, forcing it downward and making the apparatus appear as though it jetted out directly behind Styracosaurus’ skull. Thanks to a second skull that turned up later, we now know that this frill was held at a more upwards angle.

10. IT’S NAMED AFTER ANCIENT GREEK SPEAR SHAFTS.

The steel spike at the end of a spear was known as a styrax in classical Greece, this term wound up inspiring the first part of Styracosaurus’ genus name.

Source: www.mentalfloss.com

10 Cool Facts About Giganotosaurus

Sunday, December 4, 2016

Mighty Giganotosaurus

An up-and-comer in the elite club of huge, terrifying, meat-eating dinosaurs, Giganotosaurus has lately been attracting almost as much press as Tyrannosaurus rex and Spinosaurus. On the following article, you’ll discover 10 fascinating Giganotosaurus facts–and why, pound for pound, the Giant Southern Lizard may have been even more fearsome than its better-known relatives.

The Name Giganotosaurus Has Nothing to Do with “Gigantic”

A Giganotosaurus getting its teeth cleaned (Sergey Krasovskiy).

Giganotosaurus (pronounced GEE-gah-NO-toe-SORE-us) is Greek for “giant southern lizard,” not “gigantic lizard,” as it’s often mistranslated (and mispronounced, as “gigantosaurus”). This common error can be attributed to the numerous prehistoric animals that do, in fact, partake of the “giganto” root–two of the most notable examples being the giant feathered dinosaur Gigantoraptor and the giant prehistoric snake Gigantophis.
 

Giganotosaurus Was Bigger than Tyrannosaurus rex

Giganotosaurus carolinii vs Tyrannosaurus rex by Greg Paul

Part of what has made Giganotosaurus so famous, so quickly, is the fact that it slightly outweighed Tyrannosaurus rex: full-grown adults may have tipped the scales at about 10 tons, compared to a little over nine tons for a female T. rex (which outweighed the male of the species). Even still, Giganotosaurus wasn’t the biggest meat-eating dinosaur of all time; that honor, pending further fossil discoveries, belongs to the truly humongous Spinosaurus of Cretaceous Africa.

Giganotosaurus May Have Preyed on Argentinosaurus

Argentinosaurus chased by Giganotosaurus by WillDynamo55

Direct proof is lacking, but the discovery of the bones of the giant titanosaur dinosaur Argentinosaurus in the proximity of those of Giganotosaurus hints at a predator-prey relationship. Since it’s hard to imagine a lone Giganotosaurus taking down a 50-ton Argentinosaurus adult, this may be a hint that this late Cretaceous meat-eater hunted in packs.

Giganotosaurus Was the Largest Meat-Eating Dinosaur of South America

Giganotosaurus carolinii by Tod Marshall

Although it wasn’t the largest theropod of the Mesozoic Era – that honor, as stated previously, belongs to the African Spinosaurus–Giganotosaurus takes the crown as the largest meat-eating dinosaur of Cretaceous South America. (Fittingly enough, its presumed prey Argentinosaurus holds the title of “largest South American titanosaur.”)  South America, by the way, is where the very first dinosaurs evolved way back during the middle Triassic period, about 230 million years ago.

Giganotosaurus Preceded T. Rex by 30 Million Years

The Giganotosaurus lived during the the early Cenomanian age of the Late Cretaceous Period, around 97 million years ago. The T. Rex lived during the Maastrichtian age of the upper Cretaceous Period, 67 to 66 million years ago

Giganotosaurus prowled the plains and woodlands of South America about 95 million years ago, a whopping 30 million years before its more famous relative, Tyrannosaurus rex, reared its head in North America. Oddly enough, though, Giganotosaurus was a near-contemporary of the biggest known meat-eating dinosaur, Spinosaurus. Why were the meat-eating dinosaurs of the late Cretaceous period comparatively petite compared to their middle Cretaceous forebears?

No one knows, but it may have had something to do with climate or the relative availability of prey.

Giganotosaurus             Tyrannosaurus                                    

   
Period Early Cenomanian stage of the Late Cretaceous Period (97 million years ago) Upper Cretaceous Period (67 to 65.5 million years ago)
Length 12 – 15 m (40-46 feet) 12-15 m ( 40-50 feet)
Movement Biped; walked on two large, powerful back legs; fairly agile; could travel up to 31 mph. Bipedal, walked upright; powerful tail allowed it to move quickly; could run up to 45 mph.
Diet Carnivorous; preyed on herbivore dinosaurs Carnivorous; preyed on herbivorous dinosaurs, other T. Rex, scavenge
Etymology The name Giganotosaurus means “giant southern lizard” from Greek gigas (γίγας) meaning “giant”, notos (νότος) meaning “southern” and -sauros (-σαύρος) meaning “lizard”. The name “Tyrannosaurus” means “tyrant lizard”, from Greek ”tyrannos” (τύραννος) meaning “tyrant, ” and sauros (σαῦρος) meaning “lizard”.
Location South America Western North America, present Mongolia
Specimens July 1993 discovery – first skeleton 70% complete. Partial skeleton found in 1902. More than 30 partial Tyrannosaurus specimens have been found since. Over 30 specimens exist.
Height 7 m (23 feet) 4-7 m (15-23 feet)
First discovered 1993 1874
Kingdom Animalia Animalia
Introduction Giganotosaurus (“giant southern lizard”) is a genus of carcharodontosaurid dinosaur. Tyrannosaurus ( “tyrant lizard”) is a genus of coelurosaurian theropod dinosaur.
Phylum Chordata Chordata
Species G. carolinii T. Rex
Class Reptilia Reptila
Head Larger than most adult humans; relatively small brain; long skull; back of the skull had a steep forward incline. Massive, thick skull; mouth full of serrated teeth .
Teeth Sharp, 8-inch teeth; short, narrow with serrated edges Serrated, conical, continually replaced
Arms 2 short, powerful arms with sharp claws on the end of its three-fingered “hands”. 2 puny arms, couldn’t reach its mouth, two-fingered “hands”.
Tail Thin, pointed tail Powerful, pointed tail

Giganotosaurus Was Speedier Than T. rex

Giganotosaurus by Alain Beneteau

 There has been a lot of debate lately about how fast Tyrannosaurus rex could run; some experts insist this supposedly fearsome dinosaur could only attain a top speed of a relatively pokey 10 miles per hour. But based on a detailed analysis of its skeletal structure, it seems that Giganotosaurus was a bit fleeter, perhaps capable of sprints of 20mph or more when chasing down prey, at least for short periods of time.

(Bear in mind that Giganotosaurus wasn’t technically a tyrannosaur, but a type of theropod known as a “carcharodontosaur.”)

Giganotosaurus Had an Unusually Small Brain for its Size

Giganotosaurus skull

 

 

It may have been bigger and faster than Tyrannosaurus rex, but oddly enough, Giganotosaurus seems to have been a relative dimwit by middle Cretaceous standards, with a brain only about half the size of its more famous cousin, relative to its body weight. Adding insult to injury, to judge by its long, narrow skulll, Giganotosaurus’ tiny brain appears to have been the approximate shape and weight of a banana (which had yet to evolve 100 million years ago).

Giganotosaurus Was Discovered by an Amateur Fossil Hunter

Replica skeleton at the Australian Museum in Sydney

Not all dinosaur discoveries can be credited to trained professionals. Giganotosaurus was unearthed in the Patagonian region of Argentina, in 1993, by an amateur fossil hunter named Ruben Dario Carolini. The paleontologists who examined the “type specimen” acknowledged Carolini’s contribution by naming the new dinosaur Giganotosaurus carolinii (to date, this is still the only known Giganotosaurus species).

To Date, No One Has Identified a Complete Giganotosaurus Skeleton

Giganotosaurus fossil replica – Villa El Chocón

As is the case with many dinosaurs, Giganotosaurus was  "diagnosed" based on incomplete fossil remains, in this case a set of bones representing a single adult specimen. The skeleton discovered by Ruben Carolini in 1993 is about 70 percent complete, including the skull, hips, and most of the back and leg bones. To date, researchers have identified mere fragments of this dinosaur's skull, belonging to a second individual--which is still enough to peg this dinosaur as a carcharodontosaur 

As is the case with many dinosaurs, Giganotosaurus was  “diagnosed” based on incomplete fossil remains, in this case a set of bones representing a single adult specimen. The skeleton discovered by Ruben Carolini in 1993 is about 70 percent complete, including the skull, hips, and most of the back and leg bones. To date, researchers have identified mere fragments of this dinosaur’s skull, belonging to a second individual–which is still enough to peg this dinosaur as a carcharodontosaur.

Giganotosaurus Was Closely Related to Carcharodontosaurus

Tyrannotitan, a close relative of Giganotosaurus (Wikimedia Commons)

There’s something about giant predatory dinosaurs that inspires paleontologists to come up with cool-sounding names. Carcharodontosaurus (“great white shark lizard”) and Tyrannotitan (“giant tyrant”) were both close cousins of Giganotosaurus, though the first lived in northern Africa rather than South America. (The exception to this terrifying-name rule is the plain-vanilla-sounding Mapusaurus, aka the “earth lizard,” another plus-sized Giganotosaurus relative.)

Article by www.NationalGeographic.com

How Scientists Identify Species?

Sunday, December 4, 2016

A T-rex at the Natural History Museum: A new study claims that the biology of dinosaurs was skewed towards big species, with many more mammoth examples than among today's animals

How can scientists tell one species from another?

In biology, a species (abbreviated sp., with the plural form species abbreviated spp.) is the basic unit of biological classification and a taxonomic rank. A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic. For example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, or ecological niche.

All species are given a two-part name, a “binomial”. The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botany, also sometimes in zoology). For example, Boa constrictor is one of four species of the Boa genus.

Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time. Charles Darwin’s 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal gene transfer; and species may become extinct for a variety of reasons.

A collection of skeletons mounted in museums of various dinosaurs

Species description

A species is given a name when a type specimen is described formally by a scientist, in a paper that assigns it a scientific name. The name becomes a validly published name (in botany) or an available name (in zoology) when the paper is accepted for publication. The type material is provided for other scientists to examine, often in the research collection of a major museum. Scientists are asked to choose names that, in the words of the International Code of Zoological Nomenclature, are “appropriate, compact, euphonious, memorable, and do not cause offence.”

Top 10 Deadliest Dinosaurs

Sunday, December 4, 2016

Basically this is a list of the 10 most extraordinary predatory creatures of our Earth's distant past...

1) Tyrannosaurus rex

Tyrannosaurus rex predator or scavenger by numbat66

Tyrannosaurus rex (“tie-RAN-a-SORE-uss rex”) needs no introduction; its reputation as the ultimate carnivore and most badass dinosaur ever to roam the Earth precedes it. Tyrannosaurus rex (T-rex for short) literally means “tyrant lizard king”, and there can be no doubt that it lived up to its name.

Standing over five metres (16.4 feet) tall and 12 metres (39.4 feet) long, and weighing a staggering seven tons (15,400 pounds), T-rex was once thought to have been the largest terrestrial carnivore in history, but subsequent discoveries of fellow titans CarcharodontosaurusGiganotosaurus and Spinosaurus challenged this. It walked on a pair of powerful hind legs and could run as fast as a professional footballer, but balance issues meant that Giganotosaurus could outrun it. Its brain was twice the size of most other predatory giants, but its intellectual prowess wasn’t a patch on that of raptors like Utahraptor. So how does T-rex manage to cling to its crown?

It may not have been the biggest, fastest, heaviest, or smartest, but the king was the ultimate all-rounder. Its extraordinary sense of smell allowed T-rex to track prey over long distances and sniff out abandoned carcasses to scavenge. And then there is its not-so-secret weapon: its phenomenal bite, which was stronger than that of any land animal that ever lived. Its bone-splintering jaws chomped down with a force almost as huge as its own body weight, bringing to bear its 60 saw-edged conical teeth. Other dinosaurs had to close their mouth around prey multiple times to bring it down; T-rex only had to bite once.

Deadly dino fact: Dinosaurs roamed the Earth for over 160 million years, but our ten deadliest all lived in the last 60 million years of that time frame, most within the final 30 million years.

2)  Utahraptor

Artistic interpretation of the Utahraptor and iguanodont by Julius Csotonyi

The mighty Utahraptor (“YOU-tah-RAP-tor”) was three times larger and meaner than its cousin, the Velociraptor. Armed with a 30-centimetre (12-inch)-long sickle-shaped claw on each hind foot, it would kick, rip and tear its prey to death. Its leg bones were unusually thick, in order to support the powerful muscles dedicated to repeatedly driving the killing claw into its prey.

In keeping with its smaller raptor cousins, it’s possible that Utahraptor hunted in packs, like terrible three-metre (9.8-foot)-tall 500-kilogram (1,100-pound) wolves, and targeted prey many times larger than itself.

3) Velociraptor

Velociraptor skeleton by shankar s.

Star of the infamous kitchen scene in Jurassic Park, the curious creature with the deadly curved toe claw has been terrorizing nightmares for two decades.

The film may have overstated their size and stripped them of their feathers, but it did get some things right: Velociraptors (“vel-OSS-e-RAP-tors”) were fast and polished predators that oozed agility and intelligence, and may have hunted in packs.

Deadly dino fact: Dinosaurs could dominate because their legs were straight and perpendicular to their bodies, rather than in a speed-limiting sprawling stance like today’s reptiles.

4) Mapusaurus

Mapusaurus by paleoguy on Deviantart

A close cousin and look-alike of GiganotosaurusMapusaurus (“MAH-puh-SORE-uss”) hunted some of the largest dinosaurs that ever lived – the 35-metre (115-foot)-long herbivore Argentinosaurus.

Its narrow blade-like teeth were ideal slicing tools, and the discovery of bones from several individuals found in one place has experts speculating that they formed groups or hunted in packs for extra lethality.

5) Troodon

Troodon formosus by CamusAltamirano on Deviantart

Deadliness doesn’t always come down to bulk and bite force. Troodon (“TROH-oh-don”) – standing just 1.3 meters (4.3 feet) tall and weighing in at 40 kilograms (88 pounds) – was a wily whippet that made up for its lack of brawn with a whole lot of brain. In fact, it had the highest brain-to-body-weight ratio of any known dinosaur. Not only that; reconstructions of its brain have revealed nascent signs of folding – where more neural cells are packed into the same area for more efficient brain functioning – making it the most neurologically advanced specimen too.

The shape of fossilized skull remains suggest it possessed huge orb-like eyes that gave it superior vision – as well as the ability to see in low-lighting conditions and hunt nocturnally – and its slight frame made it extremely fleet of foot. While they may have been dwarfed by many of the behemoths on this list, a pack of alert and agile Troodons hunting as a pack could easily have brought down much bigger animals.

Deadly dino fact: Theropods walked upright on a pair of powerful back legs. This allowed them to run with greater speed and agility than their clumsier quadruped prey.

6) Spinosaurus

Sarcosuchus vs Spinosaurus by sameerprehistorica

Taking the title for the largest carnivorous dinosaur ever to stalk the Earth, Spinosaurus (“SPIN-oh-SORE-uss”) is thought to have been as long as one and a half double-decker London buses – 16 metres (52.5 feet) – and as heavy as a heard of full-grown Asian elephants, or 20 tons. Its vertebrae were 20 per cent larger than those of T-rex and to top it off, it sported a gigantic sail of skin supported by two-metre (6.6-foot)-long spines protruding from its back.

Despite its imposing physique, recent evidence suggests Spinosaurus spent more of its time terrorizing the water than it did the land, and would only supplement its fishy diet with scavenged carrion. Its crocodile-like jaw had smooth, conical, pointed teeth, well adapted to spearing slippery prey like Onchopristis – eight- meter (26-foot)-long prehistoric saw fish – rather than ripping flesh from bone. Special structures in its snout helped it detect pressure waves caused by prey moving in the water.

Nevertheless, Spinosaurus was fast, strong and possessed a cruel set of claws, meaning it could likely hold its own against other massive predators, like Carcharodontosaurus, who shared its territory.

7) Carcharodontosaurus

Carcharodontosaurus by Bary Miner on DeviantArt

Its name is a mouthful in more ways than one; Carcharodontosaurus (“Kar-KAR-o-don-toe- SORE-uss”) means “shark-toothed lizard” and refers to the beast’s jaw-full of 20-centimetre (eight-inch)-long serrated teeth. These could slice through flesh like switchblades through butter and leave enormous gaping wounds that would quickly incapacitate prey.

Although it was larger than T-rex and had an enormous skull the size of a person, Carcharodontosaurus – along with its close cousins Giganotosaurus and Mapusaurus – was a more primitive dinosaur with a smaller brain. Instead, it had powerful legs and fossilised tracks suggest it was capable of outrunning T-rex – at about 32 kilometres (20 miles) per hour. Whether or not it actually did – given that its disproportionately small arms would be incapable of bracing its seven-ton weight in a fall – is another matter.

Deadly dino fact: Inward-curving teeth helped give predatory dinosaurs a good grip on their prey, which prevented it from escaping in a struggle. If a dinosaur lost a tooth in battle, a new one grew to replace it.

8) Majungasaurus

Majungasaurus by Frank Lode

Majungasaurus (“Mah-JUNG-a-SORE-uss”) has a bit of a bad-lizard reputation; telltale tooth marks on Majungasaurus bones, found on its native island of Madagascar, line up perfectly with Majungasaurus’s own dental patterns.

That’s right – the evidence suggests this one-ton theropod feasted on its own kin, at least occasionally – surely the hallmark of a ruthless killer? What isn’t known, though, is whether these were the spoils of active hunts or just efficient tidying up of already-dead relatives.

9) Deinonychus

Skull of Deinonychus antirrhopus – Montana USA(33x21cm) This photograph is published in Audubon Magazine January – February 2015

The discovery of Deinonychus (“Dee-NON-i-KUSS”) in 1964 overhauled our perception of dinosaurs as languid and lumbering; here was a creature clearly built for speedy pursuit.

Almost twice the size of Velociraptor (insider tip – the ’Velociraptors‘ in Jurassic Park were actually modelled after the bigger, badder Deinonychus!), but a similar weight, it was a sprightly and most likely a quick-witted pack hunter.

Among other advantages, it possessed interlocking vertebrae that allowed its tail to stiffen for balance when running, and a retractable 13-centimetre (five-inch) claw on each foot to disembowel prey restrained in its hands and jaw.

Deadly dino fact: Be it teeth, finger claws or retractable toe claws, every one of our top ten was kitted out with some form of cutters for striking whenever an opportunity arose.

10) Giganotosaurus

Giganotosaurus carolinii by durbed

Carcharodontosaurus’s South American cousin, Giganotosaurus (“GIG-a-NOTE-o-SORE-uss”) was another beast to rival T-rex for size. Depending on the specimen, it is thought to have been slightly smaller than Carcharodontosaurus, but longer, taller and more slender than T-rex. It was the fastest of the three, besting the others by at least 16 kilometres (ten miles) per hour, perhaps thanks to its superior balance.

It had a very large skull but, like Carcharodontosaurus, it was more neurologically primitive than T-rex; its brain was a puny half the size of T-rex’s. Still, evidence suggests it had a keen sense of smell, which coupled with its athletic prowess and eight-ton bulk made it a formidable foe.

Like Carcharodontosaurus, Giganotosaurus’s teeth were serrated and laterally compressed – wide in profile but narrow when viewed from the front – making them ideal tools to deliver a series of injurious slices to the body of its prey, which would eventually keel over from exhaustion and blood loss.

Original post on www.HowItWorks.com

Tyrannotitan

Saturday, December 3, 2016

Tyrannotitan chubutensis by atrox1 on DeviantArt

Tyrannotitan is a genus of huge bipedal carnivorous dinosaur of the carcharodontosaurid family from the Aptian stage of the early Cretaceous period, discovered in Argentina. It is closely related to other giant predators like Carcharodontosaurus and especially Giganotosaurus as well as Mapusaurus. The name means “Tyrant titan”.

Estimated size of Tyranotitan, compared to a human. Author: Conty

Tyrannotitan is the geologically oldest known giant carcharodontosaurid along with the more basal Acrocanthosaurus from North America (both found in Aptian-age rocks). Unlike known carcharodontosaurids, this animal lacks pneumaticity extending into the sacral and caudal centra. The scapulocoracoid is fused, and much better developed than that of Giganotosaurus carolinii, yet the arm is very small. Most of the shaft of the scapula is missing.

Tyrannotitan chubutensis was described by Fernando E. Novas, Silvina de Valais, Pat Vickers-Rich, and Tom Rich in 2005. The fossils were found at La Juanita Farm, 28 kilometres (17 mi) northeast of Paso de Indios, Chubut Province, Argentina. They are believed to have been from the Cerro Castaño Member, Cerro Barcino Formation (Aptian stage) around 112.2 – 121 million years ago.

Before the storm by unlobogris Tyrannotitan chubutensis roaring over the carcass of his prey (a dicraeosaurid sauropod) before a storm. Some Pterodactyloids fly over the scene.

One key area of difference between Tyrannotitan and the other currently known carcharodontosaurids is the lack of pneumaticity in the sacral‭ (‬hip‭) ‬and caudal‭ (‬tail‭) ‬vertebrae.‭ ‬This essentially means that there are no air pockets that could have reduced weight resulting in a solid but heavier skeleton.‭ ‬Interestingly connected to this observation is the fact that a caudal vertebra of Tyrannotitan has a neural spine‭ (‬the projection top of the vertebra‭) ‬twice the height of the centrum,‭ ‬the main body of the vertebral bone that articulates with the other vertebra.‭ ‬The dorsal‭ (‬back‭) ‬and cervical‭ (‬neck‭) ‬vertebra do not display neural spines this high,‭ ‬and with this in mind the tail vertebrae may have had them to support a stronger muscle network that was required to carry the tail high and off the ground in the absence of weight saving features such as pneumaticity.

Mounted skeleton of Tyrannotitan

Tyrannotitan teeth do not seem to be as well developed as those of others of its group such as those seen in Carcharadontosaurus.‭ ‬Tyrannotitan teeth lack the clear curves that facilitate slicing however the general shape makes them part way similar to the teeth of allosaurids like Allosaurus itself.‭ ‬Given that the carcharodontosaurid theropods are thought to be descended from allosaurid theropods,‭ ‬the teeth of Tyrannotitan may represent a transitional form of the teeth from one changing into another.

The length of these animals has been estimated at up to 11.4–12.2 metres (37–40 ft). In 2010, Gregory S. Paul gave higher estimations of 13 metres (43 ft). Its weight has been estimated between 4.9 and 7 tonnes (5.4 and 7.7 short tons).

Shaochilong

Saturday, December 3, 2016

Shaochilong

Shaochilong (meaning “shark toothed dragon”) is a genus of carcharodontosaurid dinosaur from the mid Cretaceous (Turonian stage) Ulansuhai Formation of China (about 92 million years ago). The type species, S. maortuensis, was originally named Chilantaisaurus maortuensis, but was re-described and reclassified in 2009.

Shaochilong by KirbyniferousRegret

Phylogenetic analysis performed by Brusatte and coworkers indicate that Shaochilong is deeply nested within the carchorodontosaurids, the most derived group among the allosauroids. Shaochilong appears to be more closely related to the Gondwanan carcharodontosaurids (TyrannotitanCarcharodontosaurusMapusaurusGiganotosaurus) than the Laurasian ones (such as Neovenator and Acrocanthosaurus). Shaochilong is the youngest known Laurasian allosauroid suggesting that basal tetanurans not tyrannosaurids, were still the dominant group of large-bodied theropods in Laurasian during the Mid-Cretaceous and that the rise of tyrannosaurids as the dominant group of large terrestrial predators was sudden and confined to the very end of the Cretaceous.

The fragmentary nature of Shaochilong resulted in it being included into the Chilantaisaurus genus,‭ ‬a theropod dinosaur also from the Ulansuhai Formation.‭ ‬However while fragmentary,‭ ‬the fossil remains for C.‭ ‬maortuensis were much larger that the estimated length of two and a half meters for other Chilantaisaurus material.‭ ‬Questions were first raised‭ ‬about its validity in‭ ‬2001,‭ ‬thirty seven years after the initial description which placed the material within the Chilantaisaurus genus.‭ ‬In‭ ‬2009‭ ‬Brusatte et al.‭ ‬confirmed that the material was actually of a carcharodontosaurid dinosaur,‭ ‬a very significant discovery in itself as this was the first theropod of its kind known from Asia.‭

This basal carcharodontosaur had some impressive jaws. It would not take very many of these bites to take out the drom. By Scified.com

The material was‭ ‬renamed Shaochilong which translates to‭ ‬English as‭ ‘‬shark toothed dragon‭’‬,‭ ‬a reference to the shape of its teeth‭ (‬the carcharodontisaurid group is so named after the‭ ‬Carcharodon shark genus which include the great white shark‭) ‬combined with‭ ‘‬long‭’‬,‭ ‬a term that is increasingly used refer to dinosaurs from Asia just as the ancient Greek‭ ‘‬saurus‭’ ‬is used to describe dinosaurs in the Western World.‭ ‬The species name S.‭ ‬maortuensis is derived from the original classification of the Shaochilong material Chilantaisaurus,‭ ‬something which is standard procedure when splitting a species from an established genus into its own new genus.

Even though Shaochilong and Chilantaisaurus are now in their own separate genera,‭ ‬they are still‭ ‬related to one another,‭ ‬kind of like distant cousins.‭ ‬Their presence in the same fossil Formation also indicates that they were probably active at the same time and location as one another.

Sauroniops

Saturday, December 3, 2016

Sauroniops

Sauroniops is a genus of predatory basal carcharodontosaurid theropod dinosaur known from the Late Cretaceous (Cenomanian stage) of Morocco.

Sauroniops was a very large, bipedal theropod. It likely evolved from the Jurassic, North American Allosaurus, a large and deadly predator on its own. Being one of the largest land predators yet discovered, it grew to be 40 feet (12 meters) long, 17 feet (5.2 meters) tall, and 6 tons in weight. Although little is known or has been discovered about it, we can also get a pretty good picture of what Sauroniops was like from its carcharodontosaurian cousins, like its African relatives CarcharodontosaurusBahariasaurus, and Deltadromeus, and its South American relatives GiganotosaurusMapusaurus, and Tyrannotitan.

Eye of Sauron by Teratophoneus

In the early twenty-first century a collector donated a dinosaur skull bone to the Italian Museo Paleontologico di Montevarchi. He had acquired the specimen from a Moroccan fossil dealer, who again had bought the piece from local fossil hunters near Taouz. Its exact provenance is therefore uncertain. Later research showed that it presented a new species that was in 2012 reported and described by Andrea Cau, Marco Dalla Vecchia and Matteo Fabbri.

The same year, 2012, the specimen was by the same authors formally named in a subsequent publication as the type species Sauroniops pachytholus. The generic name has the intended meaning of “Eye of Sauron”, a demonic entity from the Lord of the Rings fantasy novel by J.R.R. Tolkien, combining its name with a Classical Greek ὄψ, ops, “eye”. Like in the novels the corporeal presence of Sauron had largely been limited to a single searching eye, Sauroniops is only known from a single bone above the eye socket. The specific name is derived from Greek παχύς, pachys, “thick”, and θόλος, tholos, “round building with conical roof”, in reference to the thick vaulted skull roof.

In an artist’s rendering, Sauroniops feeds on a young Spinosaurus while other Spinosaurus run nearby. ILLUSTRATION BY EMILIANO TROCO

The holotype, specimen MPM 2594, had probably been recovered from the Kem Kem Beds dating from the Cenomanian. It consists of a left frontal bone.

It had a large head, possibly over 5 feet (1.5 meters) long, and like its carnosaurian cousins, had long, bladelike teeth that were perfectly designed for piercing flesh.  It had two long, powerful back legs with taloned feet and somewhat short arms with three clawed hands. It also had a long, extending tail that would’ve greatly helped balance out its massive head. One feature that sets Sauroniops apart from its relatives is that it had bumps and knobs on its head that may have been used for head-butting for fighting over mates and territory. Like its other cousin, Carcharodontosaurus, it was an apex predator in Africa, and would likely have eaten anything it could catch and kill, including the hadrosaur Ouranosaurus and the sauropod Paralititan. It likely competed for territory with rivals and possibly even other large predators like CarcharodontosaurusDeltadromeusBahariasaurusSpinosaurus, and maybe even the giant crocodile Sarcosuchus.

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