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anatomical changes for bipedalism
anatomical changes for bipedalism
relationship between birds and dinosaurs
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Dinosaurs and Birds
Are birds really dinosaurs or are they simply related? That is a question that has gained new life in recent years due to the overwhelming facts the are pouring in from newly found fossils and studies from fossils that have been found in the past. Two groups have formed in the study of this question: those who believe birds are a direct result of dinosaurs and those who feel dinosaurs and birds must have had a common ancestor. Determining which view is correct is a matter of opinion based on fact. The main problem involves the use of cladistics or phylogenetic systematics to group organisms according to characteristics they share. When one looks at dinosaur fossils, he or she may feel that certain characteristics are used for something entirely different than someone else who has looked at the same fossil.
One cannot talk about dinosaur and bird lineage without mentioning Archaeopteryx. Most paleontologists agree that Archaeopteryx was the first bird. Archaeopteryx thus represents what paleontologists would call a “transitional form” between two major groups of animals, the reptiles (dinosaurs) and birds. The main difference between the theropods and Archaeopteryx were the long arms of the Archaeopteryx, adapted as wings, the feathers, and the presence of a wishbone that the theropods did not have. All of these features tie it to birds and its other characteristics tie it to theropods. One might say it was the “missing link” between the ...
Researchers believe that Incisivosaurus shows a link between typical theropods and the more rare or at least bizarre Oviraptorosaurians which are more birdlike (Gee). Xu also believes that this may show a link between the Oviraptorosaurians and an herbivorous group of dinosaurs, the Therizinosaurs. Which shows that not all of them were carnivores (Mayell).
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.
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.
Jurassic Park is the story of how one man’s idea puts many lives in danger. With lots of experimentation, scientists who worked for him were able to extract blood from prehistoric mosquitoes and other biting insects caught in amber then examine it for foreign blood cells. After that, they would extract them. Doing that, they could obtain DNA of extinct animals; dinosaurs who have been extinct for millions of years. Through a long process, they could recreate dinosaurs. Jurassic Park is a book full of suspense and horrifying murders. I wouldn’t recommend this book to everyone, but just people who enjoy science fiction and suspense. I also recommend not read Dennis Nedry’s death multiple times because it’s gross and...just gross. But other than that, I would give this five dinosaurs out of five dinosaurs!
Dinosaurs were first believed to be cold-blooded because they were thought to be related closely to reptiles which are cold-blooded creatures. Cold-blooded animals don’t actually have “cold” blood, instead they rely on the temperature from their environment to regulate their own body temperature. They do this by taking advantage of external heat by basking in the sun, and by lying in the shade to cool down. A more correct term is “ectothermic” which means “heat from outside.” On the other hand, a warm-blooded animal creates heat internally by chemical reactions inside their body. They are able to regulate their body temperature internally instead of relying on their environment. Author of the article, “Dinosaurs: Warm or Cold Blooded?” Beverly Eschberger explains, “endothermic animals have a continually high requirement for food to fuel the heat generation. Providing they can find food their constantly-optimum body temperature means that they can stay active even when it is very cold” (par 3). Even though it was believed that dinosaurs were closely related to cold-blooded reptiles, most dinosaurs had similar behaviors of a bird which is a warm blooded animal. Believing dinosaurs were warm blooded would help explain the reason why dinosaurs were so dominant and plentiful for such a long period of time. There are many other factors that play a vital role in ...
Of course it was the movie Jurassic Park who seemed to coin the phrase “Dino DNA.” This movie gave the public the thought that, a) it is possible to find dinosaur DNA and b) we can clone dinosaurs from this DNA. This essay is not going to pick apart Jurassic Park’s scientific value, however it will share the current knowledge and information on dinosaur DNA. The discovery of DNA is important because it may uncover different bits of information. The idea of cloning dinosaurs, especially at this point is out of the question. It is really hard to clone living animals today, with full DNA and genome strands, we can’t even think about recreating animals millions of years ago.
ix[9] Highfield, Roger. Dinosaur Extinction Theory ‘A Myth.’ The Telegraph – UK. March 1, 2004. Internet: http://www.rense.com/general49/tho.htm
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...
The debate of whether dinosaurs were cold blooded or warm blooded has been ongoing since the beginning of the century. At the turn of the century scientists believed that dinosaurs had long limbs and were fairly slim, supporting the idea of a cold blooded reptile. Recently, however, the bone structure, number or predators to prey, and limb position have suggested a warm blooded species. In addition, the recent discovery of a fossilized dinosaur heart has supported the idea that dinosaurs were a warm blooded species. In this essay, I am going to give supporting evidence of dinosaurs being both warm and cold blooded. I will provide background information on the dinosaur that was discovered and what information it provides scientists.
When I started this paper, I had many questions. I wanted to know what all the main theories of dinosaur extinction are and how many there are. I also wanted to know what factors in each theory would have killed these massive beasts. Other questions I had are: had dinosaurs been dying out before the event? Did any dinosaurs survive the Cretaceous/Tertiary (K/T) event? What religious beliefs contradict the dinosaurs’ very existence? The last question I wanted to address was whether or not an event such as this one could happen to us? After five papers and hours of research, some of the new questions I have are: what happened after the Cretaceous/Tertiary event? I would also now like to know if one of these theories could happen to us and how we would be able to handle it. I came up with these questions because I wanted to know we are living with this present danger. Whether a huge ice age could eradicate an entire population of humans is mind-boggling and would be extremely interesting to research. To come up with these new questions, I let my brain wander. I was joking a...
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.
Norell, Mark, Lowell Dingus, and Eugene S. Gaffney. "Why Did Nonavian Dinosaurs Become Extinct?" Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory. Berkeley: U of California, 1995. N. pag. Print.