Microraptor Zhaoianus Discovery Strengthens the Dinosaur-Bird Connection Theory
The evolutionary connection between dinosaurs and birds (that birds evolved from theropod dinosaurs) has long been theorized and is today generally accepted as a scientifically viable school of thought. Furthermore, several monumental discoveries have recently been made (21st century) in the area of the fossil record which have acted to solidify this evolutionary connection, drawing the evidentiary ties between dinosaurs and birds even closer together. Paramount among these new unearthings is the recent discovery (in 2000) of the Microraptor zhaoianus. In the following analysis I will attempt to summarize both the discovery of this unusual specie, and the impact the discovery has had on the school of thought regarding the evolution of birds.
The discovery expressed in the original article of my research is that of a Microraptor zhaoianus fossil. The Microraptor zhaoianus is classified as a non-avian, dromaeosaurid (swift lizard), which is a subgroup of the theropods1[1]. The theropods were a group of raptors whose characteristics included small size, bipedalism, and a close relation to birds2[2]. Certainly, there is no doubt that the Microraptor fits this description.
The size of the Microraptor is indeed a large part of what makes its discovery so important. On the whole, non-avian dinosaurs are classified as medium to large sized entities. However, the Microrapto is unusually small as its body measures a mere 47 mm3[3]. In fact, it is the first fully mature non avian dinosaur on record that has been found to be smaller (only slightly) than the earliest known bird, Archaeopteryx4[4]. Furthermore, in addition to its comparabl...
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...arning.com/subjects/dinosaurs/glossary/Dromaeosaur.shtml> (15 March 2004).
3[3] Xu, 705-708.
4[4] Xu, 705-708.
5[5] Anna Salleh, “Chinese macroraptor looks like bird-dinosaur link” 8 December 2000, < http://www.abc.net.au/science/news/stories/s221244.htm> (15 March 2004).
6[6] Xu, 705-708.
7[7] Xu, 705-708.
8[8] Xu, 705-708.
9[9] Salleh,1.
10[10] Xu, 705-708.
11[11] Xu, 705-708.
12[12] Xu, 705-708.
13[13] Xu, 705-708
14[14] Richard Prum, “Paleontology: Dinosaurs take to the air,” Nature 421, no. 6921 (2003): 323.
15[15] Prum, 323.
16[16] Xu, 705-708.
17[17] Paul Willis, “Dinosaur fossil with proto-feathers,” 8 March 2001, < http://www.abc.net.au/science/news/stories/s256326.htm> (5 April 2004).
18[18] Paul Willis, “Missing link from fur to feathers,” 27 April 2001, < http://www.abc.net.au/science/news/stories/s283717.htm> (5 April 2004).
Ceratopsians and Pachycephalosaurs are closely related in their characteristics. Ceratopsians processed a saddle-shaped boney frill that extended from the skull to the neck and typically had horns over the nose and eyes. The most popular was the triceratops, which could reach over 26 feet and weigh in excess of twelve metric tons. Their frills served as two major functions. It protected the vulnerable neck from being harmed. The second major function that the frill provided was due to the fact that the frill contained a network of blood vessels on its underside, which were used as a means to get rid of excess heat. The Pachycephalosaurs were considered to be bipedal. They were also found to have thick skulls, flattened bodies, and tail that were covered in an array of body rods. Pachycephalosaurs were thought to have been more than fifteen feet long and processed a skull that was surrounded by a rounded dome of solid bone. It was thought that they used their heads in combat or mating contests, but that was disproved fairly recently, which I will discuss later in the paper. Both Ceratopsians and Pachycephalosaurs were “bird-hipped” and both of these suborders contained a backwards pubic bone. Both were Marginocephilia, or “fringed heads”, which is one of three clads under the Orinthiscia order. They were also herbivore dinosaurs that inherited their fringe at the back of the skull from earlier ancestors.(2) Their classi...
It takes many experiences in order for an immature child to become a responsible, well-rounded adult. In J. D. Salinger’s The Catcher in the Rye, Salinger’s main character Holden Caulfield matures throughout the course of the novel. In the beginning of the novel, Holden is a juvenile young man. However, through his experiences, Holden is able to learn, and is finally able to become somewhat mature by the end of the novel. In The Catcher in the Rye, Holden Caulfield’s story represents a coming of age for all young adults.
Web. The Web. The Web. 11 February 2014 “Biology: Evolution”. The New York Public Library Science Desk Reference.
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.
...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.
Dinosaurs are often compared to and resemble modern day reptiles. Scientists will study how these modern day reptiles behave, look, act, and move to draw conclusions on how the dinosaurs would behave, look, act, and move. They also look at the intern make-up of the modern reptiles to predict how the dinosaurs internal make up would be. However, a recent discovery in South Dakota is stirring up some controversy (Hesman). While Mike Hammer was walking around a ranch in South Dakota he stumbled across a “big-eyed” dinosaur that he now refers to as Willo. The thing that caught his eye was the chest cavity of the dinosaur, upon further investigation he found a rock that was preserved in the curve of the dinosaur’s ribs, he was convinced that this rock was once a heart. Hammer then went on to take the dinosaur fossil in for a medical X-ray scan, this X-ray showed evidence that could change how we think about dinosaurs.
“66 Million–Year–Old Dino With A Heart.” Media Kit 17 April 2000. North Carolina University. 2000 <http://www.dinoheart.org/mediakit/index.html>.
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...
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 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.
Natural philosophers of every century of human existence have asked what we owe to each other, society or government. In The Origin of Civil Society, Jean-Jacques Rousseau argued that the only natural form of duty is to one’s family, and all other obligations are based on agreement (57). Henry David Thoreau, in 1849, wrote in Resistance to Civil Government (sometimes known as Civil Disobedience), “it is not a man's duty, as a matter of course, to devote himself to the eradication of any, even the most enormous wrong; he may still properly have other concerns to engage him; but it is his duty, at least, to wash his hands of it, and, if he gives it no thought longer, not to give it practically his support” (143). This sort of conflict, which has accompanied all men at the great changes in society, is what drives conflict in Herman Melville’s Bartleby, the Scrivener. Melville, like the Byzantine architects, crafts a work of art that studies a microcosm of the macrocosm. That is to say, by looking at the relationship between two people, Melville is able to explore the larger context around them, specifically the radical change of society in the mid-19th century. Like Thoreau, Bartleby’s famous word, “I would prefer not to,” send a shockwave through contemporary expectations and give rise to how a person approaches a situation. Bartleby and Thoreau are both transcendentalists, and look to return to a Rousseauian state of nature. They have both arrived there after a journey of self-examination – most definitely in Thoreau’s case, and most probably in Bartleby’s – and their non-conformist attitudes raise questions of what is expected of people with regard to their duty to society and each other. Bartleby in particular makes the nameless...
A quote by Charles Kegel seems to adequately sum up the problems of Holden Caulfield: "Like Stephen Dedalus of James Joyce's A Portrait of the Artist as a Young Man,Caulfield is in search of the Word. His problem is one of communication: as a teenager, he simply cannot get through to the adult world which surrounds him; as a sensitive teenager, he cannot get through others of his own age" (54).
...pdated 1995, accessed 3 Sept. 2000), Dino Buzz – What killed The Dinosaurs ? – Current Arguments,
Erdman, Shelby Lin. "Scientists Reaffirm Theory That Giant Asteroid Killed Dinosaurs." CNN. Cable News Network, 09 Mar. 2010. Web. 07 Mar. 2014.
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.