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Dinosaurs extinction
Dinosaurs extinction
Triassic jurassic extinction
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A winged creature flies silently above the forest, its beady black eyes pinpointing prey. All of a sudden, it swoops down with a startling squawk. It scoops up an unsuspecting worm and the poor, pink animal gets gobbled up in just a few bites. The creature flies off, fully fed, to find more prey for its young. Other worms and insects scramble to their homes in the ground and in the trees as another one of the monster’s shadow glides over the grass. It squawks in frustration and flies off in another direction, seeming to swim in the air. Would you believe that the scary creatures I’m talking about are just your average, feathery friends, a couple of birds? Maybe you would believe me if I told you that birds evolved from maniraptoran theropods- a group of dinosaurs! After all, without maniraptoran theropods, we wouldn’t have modern-day birds. First off, I must clear some things up. It is common knowledge that birds evolved from dinosaurs, but some people think that birds evolved from all or most dinosaurs. That part isn’t true. Can you imagine a bird evolving from a marine dinosaur, such as Pliosaur? That would just be weird. But birds DID evolve from dinosaurs. In fact, a group of dinosaurs called maniraptoran theropods.… But …show more content…
In the 1800’s, paleontologists discovered a small, bird-like creature about the size of a modern-day jay. It had the long, bony tail and a mouth full of sharp teeth like a dinosaur, but it had the beak, feathers, and wings of a bird. It was one of the only maniraptoran theropods of its time- about 150 million years ago in the late Jurassic period, an early period of dinosaurs. Also, many scientists believe that the early lizard would have been able to glide from tree to tree, looking down at the forest floor in search of prey like the birds at the
Paul, Gregory S. (2002). "Looking for the True Bird Ancestor". Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Baltimore: Johns Hopkins University Press. pp. 171–224. ISBN 0-8018-6763-0.
Underwater shark nets make us feel safer at the beach,but are we? That’s the question. Are we safe? There are lots of possibilities that the shark, with sharp like knife teeth, may outsmart us. Because of shark attacks we use nets, called shark nets. However, that doesn’t mean nets used in the past prevented shark attacks. These nets don’t only trap sharks they trap other sea creatures.
...ories of why dinosaurs went extinct abound, and as there is no theory yet to be truly confirmed as the “right one”, my theory of dinosaur cannibalism is also purely anecdotal. The discovery of the cannibalistic Majungatholus atopus in Madagascar is an important scientific find because it confirms a long-standing theory of cannibalism among certain carnivorous dinosaurs. Behavioral patterns of extinct animals are difficult to establish; however, these bones give authentication to previous unfounded beliefs about the ancient feeding practices of some dinosaurs.
The Thescelosaurus was a “bird-hipped” dinosaur or an ornithischian ( Russell 2). This herbivore lived near the end of the Cretaceous period, about one million years before the conclusion of the dinosaur era. Thescelosaurus was about the size of a short-legged pony, according to paleontologist Dr. Dale Russell and was native to North America from Wyoming up to Alberta, Canada.
The idea of cloning dinosaurs and other prehistoric life became popularized by the 1992 film Jurassic Park (based on Michael Crichton’s 1990 novel). Though it may have sparked new interest into the field of paleontology, it did so with deceiving inaccuracies. However, the technical fallacies of the actual dinosaurs are somewhat forgivable as it added to the film’s dramatic appeal. Velociraptor, as depicted in the film, was about the size of a grown man. In reality, velociraptor came to about the kneecap. Furthermore, velociraptor would more likely have been covered in feathers rather than the lizard-like skin portrayed in the movie. One scene shows velociraptor fogging the window of a door. This is an endothermic or warm blooded trait as it implies the dromaeosaurid’s body temperature is above the temperature of his environment. There is also no evidence of dilophosaurus bearing a neck frill, and brachiosaurus did not have the ability to chew his food in a circular motion (iguanodon was the first dinosaur to develop this technique by acquiring back molars to allow for equine or bovine-like chewing). Fortunately, tyrannosaurus remained very close to his biological authenticity, with the only paleobiological errors stemming from a lack in computer animation such as rudimentary ball and joint programs. However, the erroneous nature of the deoxyribonucle...
ix[9] Highfield, Roger. Dinosaur Extinction Theory ‘A Myth.’ The Telegraph – UK. March 1, 2004. Internet: http://www.rense.com/general49/tho.htm
When you make the choice to adopt a pet from the humane society you are providing that animal with a better quality of life.
5 The Field Museum. (2002). New Species Clarifies Bird-Dinosaur Link. Science Daily [online], 14 Feb 2002. Available at http://www.sciencedaily.com/releases/2002/02/020214080242.htm
We use dinosaurs to represent the changes in nature that have occurred throughout time. Studies found that although the “oldest rock did not show evidence of life, the progression of plant and animal life that changed in recognizable intervals, from ancient life, age of reptiles to the age of mammals” (Dino Nature Metaphor, slide 6), measured the age of the earth. When we think of dinosaurs in relation to nature, we think of that very powerful force that controls the cycle of life. Nature was able to yield such magnificent ferocious creatures that walked the earth and then take them back when they served nature’s purpose. Dinosaurs fit perfectly in nature’s constant
...ll. This group still remained successful during the Jurassic period and had a wide geopraphic distribution. Other reptiles evolved to not only live on land, but to fly. The earliest known birds appeared during this period; Archaeoteryx being the first to be considered the intermediate between the birds and predatory dinosaurs. It is debated on whether this ancient bird could actually fly or merely glid from tree to tree. Carnosaurus, meaning “meat-eating” is another group of dinosaurs that ruled during the Jurassic. With such large herbivorous prey animals, the correlation of these large predators make sense of why they were so common. An Allosaurus was one of the most common Carnosaurs in North America. Upon finding numerous intact skeletons in fossil beds, it has been reported that the Allosaurus was superficially similar to the later evolving Tyrannosaurus rex.
Fossil evidence suggests that the Cathartid (New World) vultures have been around for quite some time with two fossil species dated from the early Oligocene (about 35 million years ago). During the Pliocene and Pleistocene (about 2 million years ago) th...
A very deadly and contagious disease may have circulated among the dinosaurs forcing them to become extinct. Still yet another theory is that the Earth just gradually changed in climate over a long time period and the dinosaurs were not able to adapt to the cooler, dryer climate. There are probably other theories as to how the dinosaurs became
Several models have been proposed to explain why might Archaeopteryx or its decedents develop the ability to fly. The “pouncing proavis” or “trees-down” model was proposed by J.P. Garner and colleagues in 1999. They theorize that birds evolved to the ability to fly by first living in trees and then gliding down to ambush prey. Natural selection favoured individuals that could glide the furthest to catch prey and eventually led to the origin of flight. Garner and colleagues (1999) believed that this theory explained three aspects of early flight: the model matches observed secession in flight evolution based on fossil records, it predicts a primitive bird-like animal had few adaptions to flapping but very complex aerodynamic feathers, and it explains the origin of rachis in feathers.
The sun dried grass crunched under David’s feet as he reached the mailbox, sweat plastering his golden hair to his forehead. The rural landscape of Shark Bay is bone dry; the lingering heat wave serving as a slap in the face with the wind blowing what is left of his fields into whirlwinds of dirt. His was once a land of luscious green landscape, the soft air turned branches into wind chimes as the trees swayed. These same trees have been bleached by the heat ridden gusts carving tortured sculpture in their trunks. Some might now see this world as one of desolate wasteland but David grew up with the land, this land was a living, growing friend that he knew, loved, and cared for as much as he did his wife and children.
Reptiles are vertebrate, or backboned animals constituting the class Reptilia and are characterized by a combination of features, none of which alone could separate all reptiles from all other animals.The characteristics of reptiles are numerous, therefore can not be explained in great detail in this report. In no special order, the characteristics of reptiles are: cold-bloodedness; the presence of lungs; direct development, without larval forms as in amphibians; a dry skin with scales but not feathers or hair; an amniote egg; internal fertilization; a three or four-chambered heart; two aortic arches (blood vessels) carrying blood from the heart to the body, unlike mammals and birds that only have one; a metanephric kidney; twelve pairs of cranial nerves; and skeletal features such as limbs with usually five clawed fingers or toes, at least two spinal bones associated with the pelvis, a single ball-and-socket connection at the head-neck joint instead of two, as in advanced amphibians and mammals, and an incomplete or complete partition along the roof of the mouth, separating the food and air passageways so that breathing can continue while food is being chewed. These and other traditional defining characteristics of reptiles have been subjected to considerable modification in recent times. The extinct flying reptiles, called pterosaurs or pterodactyls, are now thought to have been warm-blooded and covered with hair. Also, the dinosaurs are also now considered by many authorities to have been warm-blooded. The earliest known bird, archaeopteryx, is now regarded by many to have been a small dinosaur, despite its covering of feathers The extinct ancestors of the mammals, the therapsids, or mammallike reptiles, are also believed to have been warm-blooded and haired.