Pachycephalosaurus

Type Species: Pachycephalosaurus wyomingesis
Classification: Dinosauria - Ornithischia - Marginocephalia - Pachycephalosauridae - Pachycephalosaurini
Time Period: late Cretaceous
Location: North America
Diet: Herbivore

Pachycephalosaurus, the arch-type of the pachycephalosaurs, was first discovered in Montana. Its name means "thick headed lizard," and it fits the stereotype. Its known only by a number of large domed skull roofs and one nearly complete skull. This dinosaur's domed head could be up to nine inches thick. As to the purpose of the dome, speculation ran rampant until a couple years ago. Scientists analyzed the domed skulls and discovered indentations similar to those found on the bones of modern animals that head-butt; this has led scientists to conclude that Pachycephalosaurus did indeed butt heads. Males may have engaged in contests for females or territory. A secondary purpose of the skull could've been defensive: a blow from a charging Pachycephalosaurus could splinter bone and rupture organs.

This dinosaur's snout was covered with sharp spikes and dull horns. Its teeth were simple, nothing more elegant than triangular blades used to squash food. This has led paleontologists to speculate that it probably fed on a diet consisting mainly of soft vegetation.

Tyrannosaurus

Type Species: Tyrannosaurus rex
Classification: Dinosauria - Saurischia - Theropoda - Tetanurae - Tyrannosauridae
Time Period: late Cretaceous
Location: North America
Diet: Carnivore

From storybooks to kids' drawings, to professional art and worldwide cinematic hits, Tyrannosaurus rex is worshiped and revered as the titan of the dinosaur world. Its very name means "tyrant lizard," and media harps upon this fact. Remains of more than fifty skeletons have been discovered throughout North America, in Wyoming, Colorado, Texas, South Dakota, and as far north as Alberta, Canada. Tyrannosaurus was one of the largest carnivores of dinosauria (the current title of carnivorous heavyweight champ goes to Spinosaurus, and Tyrannosaurus ranks tenth). Although he's lost the championship title, Tyrannosaurus remains an imposing figure:

"What are we to make of those scrawny forearms?" The first Tyrannosaurus skeletons were incomplete, and paleontologists speculated that it had larger three-fingered arms like that of Allosaurus. When complete skeletons were found, including the world-famous "Sue", it became apparent that Tyrannosaurus did indeed have (what appeared to be) scrawny arms. Biomechanical analyses of the arms, however, imply they may not have been that scrawny after all. The cortical bones in the arm were thick, implying an ability to withstand intense pressure and heavy loads; the bicep muscles would've been able to lift 439 pounds. I don't know any human who can do that, and if humans were as large as Tyrannosaurus, this dinosaur would still be able to lift 3.5 times as much weight as a human would. These arms weren't scrawny at all; despite their size, they could be used to grapple and hold prey while the jaws went to work. It's been said that what matters isn't size but how you use it; Tyrannosaurus' arms are a Case Study of this fact. 

fighting over a carcass? or defending a kill? Read more below!

An ongoing debate regarding Tyrannosaurus has to do with its diet: "Was it a scavenger or a predator?" Some have argued that because of its short forearms and awkward build, it wouldn't have made a good predator; if it fell, for instance (as might happen in a contest against an armored herbivore), it would have a hell of a time getting back to its feet. For a time the evidence lie with those arguing for a scavenging diet, but lately this has gone out-of-style. Tyrannosaurus seems built for hunting: its eyes face forward and not to the side as with most carnivorous dinosaurs, allowing for depth and distance to be gauged; the strong yet lightweight skull made for a formidable attack; and its muscular jaw, with specialized hinges that allowed the bottom jaw to be lowered unusually low to take in large chunks of meat, could've served as a "grappling hook" against struggling prey. Its legs were extremely muscular; at a walking pace, it could move close to five miles an hour, and it could top thirty miles per hour in a brisk jog. The nail in the coffin of the Pro-Scavengers came in 2013; up to that point, there were hints here-and-there that Tyrannosaurus was a hunter: bones with bite marks, broken teeth near skeletal remains, and foot tracks indicating pursuits. In 2013, however, a remarkable find was made: a Tyrannosaurus rex tooth was found embedded in the tailbone of a hadrosaur. The hadrosaur's tailbone had healed over the tooth, indicating that it had escaped its predator to live another day. 

an Anatotitan Rodeo!

Edmontonia

a club would be REALLY helpful right about now

Type Species: Edmontonia longiceps
Classification: Dinosauria-Ornithischia-Thyreophora-Ankylosauria-Nodosauridae
Time Period: late Cretaceous
Location: North America
Diet: Herbivore

Edmontonia's back was covered with an array of small, flat keeled (ridged) plates. Its neck and shoulders were plastered with larger keeled plates, and spines protruded forward from its shoulders. More spines ran along the sides of its body, tapering to nothing near its hips. This short, squat dinosaur no doubt used the spines as protection against predators and may have also used them in courtship displays or to battle with other males for potential mates. Edmontonia was a smaller dinosaur, but I'd still be willing to ride him:

Cryolophosaurus

Type Species: Cryolophosaurus elliotti
Classification: Dinosauria-Saurischia-Theropoda-Tetanurae
Time Period: early Jurassic
Location: Antarctica
Diet: Carnivore

The remains of Cryolophosaurus were found in the barren colds and wastes of the Trans-Antarctic Mountains. Although some paintings of this carnivore depict it tramping through snow and shaking its weird crest this way and that in a blizzard, Antarctica in the early Jurassic wasn't where it is today; it was nearer the equator, and part of a larger continent; the climate would've been warmer and the land replete with temperature forests. Cryolophosaurus has been called the "Elvis Presley" of the dinosaurs because of its twin set of backward-sweeping crest that resembles Presley's infamous hairdo. Cryolophosaurus sported small horns adjacent to the backward-sweeping crests, Measuring at about twenty feet long, Cryolophosaurus was to the early Jurassic what Tyrannosaurus was to the late Cretaceous: the King of the Tyrants. 

Although Cryolophosaurus was the largest predator of its day (the much larger Allosaurus wouldn't come until millions of years later), paleontologists speculate that it may have been a scavenger rather than a hunter; the crests were relatively frail, and the ferocity of the hunt would likely damage the crests. Because the crest bones have been intact, it makes more sense that Cryolophosaurus scavenged for its food. One large skeleton of this dinosaur indicates it may have been a voracious eater: what looks like an herbivorous dinosaur's rib was found wedged inside the bones of the Cryolophosaurus' throat! Some postulate that this dinosaur choked on its dinner; others argue that the rib belongs to Cryolophosaurus and was maneuvered into that weird position after death. As to the purpose of this dinosaur's crest, it probably served as courtship decoration. 

And just for shits and giggles, here's a cool video of a pair of Cryolophosaurus battling it out!

Parasaurolophus

Type Species: Parasaurolophus walkeri
Classification: Dinosauria - Ornithischia - Ornithopoda - Hadrosauridae - Lambeosaurinae - Parasaurolophini
Time Period: Late Cretaceous
Location: North America
Diet: Herbivore

What better way to kick off "Dinosaurs of 2015" with the sexiest dinosaur of them all? Parasaurolophus is my all-time favorite dinosaur, and she's had cameos in The Land Before TIme and the Jurassic Park movies. She was a big bitch, too:

and that's for a full-grown adult. She'd look MUCH bigger to me.

Her name means "like Saurolophus," since both dinosaurs had trombone-like crests protruding from the backs of their heads. But whereas Saurolophus' crest was solid bone, Parasaurolophus' crest was hollow and lined with looping nasal cavities running from the nostril on the crest to its throat. You can get a sense of this dinosaur's size (as well as the size of its swooping trombone-like crest) in this clip from The Lost World:

As to the purpose of the crest, paleontologists have offered lots of theories (none testable, of course). There's the theory that it was a snorkel for underwater swimming, that it could've been the "entrance" to an air container so that Parasaurolophus could submerge beneath the waves. I don't think this is too likely: despite the proliferation of movies presenting this dinosaur in the water, research within the last decades has shown how the water pressure wrapping around these titanic dinosaurs when submerged would've been strong enough to crush their ribs. Others theories include its intensification of scent, it was an area used to "cool off" the brain, or that it was a horn used for social display, identifying its age and sex and herd membership. 

The most widely-accepted theory is that the crests were used to emit sounds. These noises would warn of impending danger, attract potential mates, or signal to other members of the herd. The nasal loops within the crest lend credit to this theory. A vocal organ such as a voice-box would make the sounds, and the sound would then be pushed through the hollow tubes within the crest, giving the creature a deep, bellowing rumble. Scientists have mapped the nasal loops and have run simulations to determine what the sounds would've been like:

That's the trumpeting of a dinosaur.

A cry out of place in this world.

A howl very, very alien.

Stygimoloch

Type Species: Stygimoloch spinifer

Classification: Dinosauria - Ornithischia - Marginocephalia - Pachycephalosauridae - Pachycephalosaurini

Time Period: late Cretaceous

Location: North America

Diet: Herbivore

A contemporary of my favorite dinosaur Parasaurolophus, my second favorite dinosaur is this wicked-looking devil to the left. His name means "the horned devil from the river of Hell," since (a) it's a horny bastard and (b) lots of its remains have been found in the Hell Creek Formation in Montana (the sty is inspired by the River Styx in classical mythology; moloch is derived from the pagan god by the same name, who would be identified by Judeao-Christian sources as "the Devil"). 

Stygimoloch was a medium-sized pachycephalosaur, dwarfed by its relative Pachycephalosaurus, the most widely-known pachy of them all! This guy's skull was decorated with horny bumps, piercing horns, and spikes; it also had the domed skull, a signature of the pachycephalosaurs. The horns ran from the base of the dome to the snout. The skull horns may have been used for butting enemies in dire circumstances, or maybe even in mating rituals, but because the horns are relatively weak, they were probably used solely for courtship displays. The horniest Stygi got the chic. Here's a size comparison between a human being and our Dino of the Week:

Interesting fact: rather recently, some paleontologists have started advocating the idea that Stygimoloch is simply the juvenile version of Pachycephalosaurus. That's an interesting take, but I hope they're wrong: I don't want to find a new 2nd Favorite Dinosaur.

Triceratops

Type Species: Triceratops horridus
Classification: Dinosauria – Ornithischia – Marginocephalia – Ceratopsia – Neoceratopsia – Coronosauria – Ceratopsoidea – Ceratopsidae - Chasmosaurinae - Triceratopsini
Time Period: late Cretaceous
Location: North America
Diet: Herbivore

Triceratops was, in one word, massive. Stocky legs built like iron suspended its barrel-like rib-cage. Its known for its three horns (two protruding from above the eyes and a third from the nose), but not all Triceratops specimens have three horns. These burly creatures would dwarf any of us in their shadow:

The brow horns probably had a horny covering, and the base of the horns was actually hollow. This open space is called a sinus; it helped to cushion the brain when the horns were "in action," acting as a shock absorber. These sinuses are found in modern-day goats, sheep, and cows. And while Triceratops is often portrayed as the stereotypical ceratopsian, its skull frill was unique: most ceratopsians had fenestrae, or open-air cavities, in their frills that would be covered with skin in real life. These fenestrae helped keep the frill relatively light. Triceratops lacked such cavities, rendering its frill extremely heavy (this explains why its frill was smaller than most ceratopsians of its size). Their large beaks were powerful and scissor-like, and they would've been able to slice clean through a human arm. Their jaws were lined with tightly-knit teeth used for grinding their food. Triceratops wasn't the brightest bulb on the dinosaur tree; its brain was small for its size, even smaller than those of the "duck-billed" ornithopods, or carnivores.

Healed wounds in Triceratops' frill show that this dinosaur had a burly temperament. This hot-headed dinosaur probably fought against others in its herd, warring over females, territory, or leadership. The horns may have served the same purpose as antlers in modern-day moose: rather than attacking members of the own herd, Triceratops may have vied for dominance by locking horns with an adversary and "wrestling" until the weaker backed down. The horns would've been helpful not just in battling other males but also in defending itself against predators; recent models suggest that the horns packed such a punch that they could shatter solid bone. Nothing in the world today could withstand the charge of a bull Triceratops, so any hungry tyrannosaurs would have to think twice before taking the bitch on.

he's thinking, "I should've thought twice..."

Ankylosaurus

Type Species: Ankylosaurus magniventris
Classification: Dinosauria-Ornithischia-Thyreophora-Ankylosauria-Ankylosaurini
Time Period: Cretaceous
Location: North America
Diet: Herbivore

Ankylosaurus was the tank of the dinosaur era. If James Gurney's Dinotopia took place in 1930s Europe, Ankylosaurus would be leading the German blitzkrieg. The entire top side of its body was heavily armored with thick, oval plates embedded in its leathery skin. Two rows of spikes ran along its body, large horns protruded from the back of its head, and it sported a club-like tail. My attempt at describing it reminds me of the weird apocalyptic angels seen in the biblical literature; this animal is just that weird. Only its underside was un-plated, so that flipping it over was the only way to wound it (and that would be quite a feat, seeing as these guys weighed in around 3.5 tons!). Ankylosaurus had four short legs (though the hind legs were larger than the front), a short neck, and a wide skull with a teeny brain. Its diet consisted of plants (that's an herbivore, if you're into the lingo), and it probably had a fermentation compartment in its bowels to aid in the digestion of the tough plant material (this would make it fart a lot). Ankylosaurus trackways have been found in Bolivia, showing that these animals could run at a "decent jog," according to Christian Meyer, a Swiss paleontologist working at the site (speed estimates are made by measuring the distance between the footprints, the animal's leg length, the pattern of the tracks, and other factors that are tossed into an algorithm). 

Because a complete skeleton has yet to be found, estimates on Ankylosaurus' size vary; a conservative estimate puts it at about 25-35 feet long and six feet wide and four feet tall. As far as weight goes, we're talking 3-4 tons. Here's what the "fused lizard" would look like facing off an African elephant.

the ankylosaurus would win

Stegosaurus

Type Species: Stegosaurus armatus
Classification: Dinosauria-Ornithischia-Thyreophora-Stegosauria-Stegosauridae-Stegosaurinae
Time Period: late Jurassic
Location: North America & Europe
Diet: Herbivore

The "roofed lizard" is one of the most famous dinosaurs, ranking in popular lore alongside Tyrannosaurus and Triceratops (though Stegosaurus would've never met any of the other two; they were separated by millions of years). Stegosaurus weighed more than two tons and foraged on low-lying plants. Because its diet would've been composed of ground-hugging foilage, it wouldn't had to compete against the titanic sauropods that shared the land during the late Jurassic. Stegosaurus had a small head with weak jaws, and a beak at the front of the mouth chopped vegetation. Inside the mouth, dozens of leaf-shaped teeth ground the vegetation prior to digestation. The front legs were only half as long as its hind legs, but they were stout and able to carry the weight of the dinosaur's "upper-body"; the disproportion between the front and hind legs gave Stegosaurus a steep arch down towards the head, making the hips the tallest part of its body. 

While Tyrannosaurus is known for its scrawny arms and killer teeth, and while Triceratops is known for its three horns and bony frill, Stegosaurus has gathered renown because of the two rows of staggered bony plates running along its back. These plates started off smaller at the head, were biggest at the hips, and then decreased towards the tail. These plates measured several inches thick at the base but became thin and narrow at the tips. These knobs and plates in the skin helped to strengthen and protect the dinosaur's flanks and hips. Some reconstructions even show the plates pointing downward from the back, covering its sides as a sort of roofed protection; these artists speculate that the plates were misaligned at burial. Four ghastly spikes protruded from its tail, and it probably used these as deterrents against the larger predators of the late Jurassic (such as Allosaurus and Ceratosaurus; remember, T-Rex wasn't around!). Here's a famous painting of a Stegosaurus fleeing from a pursuing Allosaurus:

you know he's gonna get it

Endocasts of Stegosaurus' skull show that it had a small brain. This doesn't rule out intelligence, but it certainly doesn't argue for it. In the past, scientists believed that because Stegosaurus had such a tiny brain (about the size of a dog), it must've been a dumb, lumbering animal; this, in turn, led to the widespread belief that all dinosaurs were dumb brutes. Nowadays such a belief is a paleontological anathema (though we can probably assume that Stegosaurus' intelligence is just what would've been needed for a slow-moving, ground-hugging, armored eater). In the burgeoning days of dinosaur discoveries, paleontologists sought to compensate for its small brain by postulating a second brain in its hip region; they based this off the evidence left behind by the sacral plexus, which was a bundle of fleshy nerves that helped with the function of the spinal cord. Regardless of its intelligence, it's still a wicked cool dinosaur, and it could fuck you up. 

you could downright impale yourself on those spikes

Megalosaurus

Type Species: Megalosaurus bucklandii
Classification: Dinosauria - Saurischia - Theropoda - Carnosauria - Megalosauroidea - Megalosauria - Megalosauridae - Megalosaurinae
Time Period: Middle Jurassic
Location: Europe (England)
Diet: Carnivore

The remains of Megalosaurus were first documented in the 17th century, and the bone discovered was described by Robert Plot as the thighbone of a Roman war elephant; it was later attributed to one of the giants of biblical lore. In the 18th century, the first name given to it was Scrotum humanum; in the next century, scientists began realizing they'd stumbled upon something extraordinary. In 1824, realizing that the bones probably belonged to a giant reptile, its name was changed to Megalosaurus, and in 1827 it became Megalosaurus bucklandii. Its name literally means 'Great Lizard.' Sir Richard Owen, who coined the name Dinosauria, included reproductions of Megalosaurus in the Crystal Palace. His depiction of Megalosaurus looks nothing like what modern paleontologists believe it to have looked like. Owen's recreations were founded on the assumption that dinosaurs were nothing more than big lizards, and the recreations muddled discoveries from different dinosaurs into a somewhat-coherent picture:

As dinosaur discoveries have intensified, more remains of Megalosaurus have been discovered, offering a more complete picture of this theropod. Megalosaurus reached up to twenty feet long snout-to-tail, and it weighed around 1500 pounds. It was bipedal, walking on stout hind legs and balanced by a tail held horizontal from the body. Its arms were robust but short. It had a large head filled with curved teeth. While many of the early theropods were lithe and agile, or at least stream-lined, Megalosaurus was robust and heavily-muscled.

This Jurassic theropod was smaller than its Cretaceous descendants, but that didn't make it any less ferocious. For many years, any theropod fossils discovered were deemed as Megalosaurus. Famous dinosaurs such as Tyrannosaurus, Allosaurus, and Dilophosaurus were thrown into the Megalosauridae family, making it the "waste-basket" of theropod dinosaurs. Nowadays, however, paleontologists have distinguished Megalosaurus from its ancestors and descendants, and Megalosaurus stands in a category all its own.

Apatosaurus

Type Species: Apatosaurus ajax
Classification: Dinosauria-Saurischia-Sauropodomorpha-Sauropoda-Diplodocidae-Apatosaurinae
Time Period: late Jurassic
Location: North America
Diet: Herbivore

Othniel Marsh, the paleontologist who discovered Apatosaurus, created its name from a combination of Greek words: apate (meaning "deceptive") and sauro, meaning "lizard." This dinosaur was deceptive indeed, and legions of schoolchildren have learned about Apatosaurus under the pseudo-name Brontosaurus (but that is another tale for another time). Marsh named this sauropod the "deceptive lizard" because its monstrous bones resembled those of mosasaurs, a large marine reptile whose remains are scattered throughout North America. Apatosaurus could reach up to seventy feet long from the head to the tip-o'-the-tail, and they could weigh over thirty tons (the equivalent of five adult African elephants). Their hips, at twelve feet above ground level, were the highest parts of their bodies (except for the head perched atop the neck). 

a full-grown Apatosaurus stretched nearly as long as three Abram Tanks

Apatosaurus is one of the largest land animals found in the fossil record, though it's dwarfed by many of the later sauropods that would evolve during the Cretaceous. These dinosaurs traveled in herds, and one can image the sight of dozens upon dozens of these lumbering behemoths shaking the ground in their slow and steady foraging march. Their long, thick tails ended in a whip, and despite earlier depictions of these sauropods with their tails dragging along the ground like those of alligators, Apatosaurus would've held the tail off the ground. Muscles attached to the tail bones kept the tail rigid, but the muscles also enabled Apatosaurus to lash the tail against predators. Although the tail would've served as a whip of monstrous proportions, the main function of the tail was that of a balancing beam; by holding the tail directly outwards from the body, Apatosaurus was able to distribute its massive weight between its head and tail so that it didn't topple over from being so top-heavy. 

Its stout legs were held straight beneath their bellies, with blunt toes at the feet. Its chest was gargantuan and the ribs were like cages, protecting the internal organs and the pumping heart. Its vertebrae were tall and straight, filled with hollow gaps to make them lighter. Apatosaurus fed day and night; because of their size, they had to constantly eat. To allow time for sleep, they swallowed their food whole, allowing gastroliths (stones swallowed to mush up the tough plant fibers within their bowels) to do the main work. Their necks reached high, but because of the weight and structure of the neck bones, they had a limited range for raising their necks; the thickest regions of the neck couldn't be lifted above their shoulders. The skull tapered to form a shallow mouth lined with delicate teeth at the front of the jaws for stripping foilage off the trees. 

Apatosaurus is replete with misinformation. As aforementioned, early depictions of Apatosaurus depicted it dragging its tail along the ground in the vein of modern reptiles; however, biomechanical reconstructions of Apatosaurus' skeleton show that this isn't accurate. Furthermore, sauropod trackways show no tail marks, and sauropod tail bones don't show any wear or tear from becoming tangled in plants or caught in cracks in the rocks, as one would expect if Apatosaurus dragged its tail. Another misconception is that Apatosaurus (or sauropods in general) spent most of their time in the water; but Apatosaurus shows no adaptations for this behavior, and trackways are found in semi-arid areas where water isn't overly abundant. In addition, the water pressure that would be exerted on the mammoth Apatosaurus would likely have crushed the animal's rib cage, and this would be far from conducive to survival and reproduction. Adult Apatosaurs had few enemies, but the juveniles would've been easy prey to any lurking predators; trackways of these migrating sauropods show that the young were kept in the middle of the herd, protected from the outside by the larger, grown-up sauropods.

Chasmosaurus

Type Species: Chasmosaurus belli
Classification: Dinosauria – Ornithischia – Marginocephalia – Ceratopsia – Neoceratopsia – Coronosauria – Ceratopsoidea – Ceratopsidae - Chasmosaurinae
Time Period: middle Cretaceous
Location: North America
Diet: Herbivore

Chasmosaurus is recognized by the large fenestrae in its massive, rectangle-shaped frill. Most ceratopsians had hollow openings in their frill (fenestrae) that would be covered with skin in actual life, and Chasmosaurus has some of the largest fenestrae of any ceratopsians; hence the meaning of its name, "Chasm Reptile." Paleontologists speculate that the skin over the fenestrae was filled with blood vessels that enabled the skin to flush bright colors; this would be profitable for mating season, warding off predators, or even communicating among members of the herd.

Chasmosaurus had three horns on its face. The brow horns weresmall and blunt, perhaps serving as decorative pieces. The nasal horn seems built for serious business. Long and powerful, a jab from this horn could cut through the thickest flesh. Some specimens have smaller horns, and paleontologists speculate this is due to sexual dimorphism (phenotypic differences between males and females of a certain species). Chasmosaurus' skin was pebbly, rough, and thick like double-layered leather. Circular tubercles ran in regularly spaced rows across its skin, with smaller tubercles between the slender rows.

any depiction of Chasmosaurus sex is post-worthy. period.

Deinonychus

Type Species: Deinonychus antirrhopus
Classification: Dinosauria-Saurischia-Theropoda-Tetanurae-Avetheropoda-Coelurosauria-Maniraptora-Paraves-Dromaeosauridae
Time Period: early Cretaceous
Location: North America
Diet: Carnivore

Deinonychus belongs to the dromaeosaurids, a sub-group of theropods whose name means "running lizards." These "raptors" (a slang term popularized by the movie Jurassic Park) were fast, agile, medium-sized theropods who were (likely) covered in feathers and (probably) hunted in packs. Deinonychus was one of the first dromaeosaurs discovered. They were powerful, bristling with muscles. A large head rested upon their shoulders, and their jaws, though relatively weak, made up for lack of strength with gruesome teeth angled towards the back of the mouth. These backward-facing teeth would've helped Deinonychus to hold struggling prey and to rip flesh off bone. Its long arms dangled down, each with a three-fingered hand; each digit ended in a bloodcurdling claw. These fingers were flexible, hinting that they were probably used as a main weapon of attack. The femur (thigh bone) was smaller than the tibia and fibula (the shin bones), which was a common feature among dromaeosaurs; this set-up enabled Deinonychus to run fast. The hind legs were tridactyl, meaning that they walked on only three toes.

One of Deinonychus' most memorable features is the slashing claw on each foot. These claws were sickly and curved in an arch; the claw would be held up off the ground when the dinosaur was running. This claw could be flicked easily, tearing into flesh and then ripping back. A good swipe of this claw could disembowel prey. Although media portrays the "killer claw" as the main weapon in the dromaeosaur arsenal, it's likelier that the claws helped Deinonychus to latch onto its prey while attacking with its razor-sharp hand claws. Thin rods of bone ran along the vertebrae of the tail, holding it stiff off the ground. Where the tail connected to the body, however, it was flexible, allowing it to sway up, down, left, or right; this would help balance the animal during vicious assaults.

Deinonychus was probably a pack hunter; several individuals coordinated attacks to take down large prey. An important discovery (depicted below) was the remains of several Deinonychus and a single Tenontosaurus tangled together in the grip of a desperate battle. This remarkable find is a powerful piece of evidence stacked in favor of Deinonychus hunting in packs. 

Recent portrayals of Deinonychus show it covered in feathers. While there's no evidence that Deinonychus in particular had feathers, the proven existence of other feathered dromaeosaurs (such as Velociraptor) implies that dromaeosaurs were probably feather-covered. Many paleontologists speculate that most theropods, including Tyrannosaurus, had feathers at some stage in their lives. This lends credence to the idea that modern-day birds are descended from theropod dinosaurs.

#tantricfeathers