Dinosaur Physiology and Questionable Four Chambered Heart Discovery
In recent years, there has been cardiovascular evidence that questions the widely held belief that dinosaurs were indeed ectothermic. There was a discovery of a skeleton encased in sandstone that closely resembled a Thescelosaurus. The set of bones had a heart shaped rock within the chest region. Tests are being done to find out if this heart is in fact the suggested four-chambered heart. If it is, then there could be important changes in the theories of dinosaur physiology.
This case is somewhat provocative because it makes claims that the suggested four-chambered heart and single aorta strongly indicate that dinosaurs were warm blooded and able to maintain their body temperature by having a faster metabolism. Virginia Morell writes that experts saw, “two large, oval chambers or ventricles, divided by a septum” (Morell). If what was found was indeed a heart, its anatomy resembles that of birds and mammals, not reptiles. Most modern reptiles have a three-chambered heart with two arches leading from the heart to the body; oxygen rich blood then mixes with oxygen poor blood. No direct evidence of the cardiovascular system has been reported in any archosaur fossil. If the suggested heart has a single aorta, then it would be endothermic. This provides a feature that would associate the dinosaur with today’s birds. If the Thescelosaurus, called “Willo,” did have a four-chambered heart, then this might also strengthen the hypothesis that some dinosaurs were ancestors of today’s birds.
Michael Hammer, a professional fossil preparator from Oregon, found the skeleton in South Dakota in 1993. The dinosaur in question ...
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...ws that there is no definite answer even if our society’s technological advances are able to show detailed images of fossils. This is important because it shows that Science is not static, but more prone to the ambiguity of truth and fact with the advancements of new evidence--thus, forcing one to question what he or she may define as “fact.”
Works Cited
Fisher, et al. 21 April 2000. “Cardiovascular Evidence for an Intermediate or Higher
Metabolic Rate in an Ornithischian Dinosaur.” Science, v. 288, pg 503-505.
Morell, Virginia. 21 April 2000. “Revealing a Dinosaur’s Heart of Stone.” Science,
v. 288, pg 416-417.
Oglesby, Christy. 21 April 2000. “Heart of a Dinosaur.” CNN.com.
5 April 2004. <www.cnn.com/2000/fyi/news/04/21/dinosaurs/#1>
Rowe, Timothy. 2 February 2001. “Dinosaur with a Heart of Stone.” Science,
v. 291, pg 73.
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...
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.
The article from Science News, “Telltale Dino Heart Hints at Warm Blood”, by Tina Hesman and the Journal article it was based on from Science, ”Cardiovascular Evidence for an Intermediate or Higher Metabolic Rate in an Ornithischian Dinosaur”, by Paul Fisher and others both offer a new perspective on the topic to be discussed, however there are some key differences between the two articles. How the two articles differ will be discussed later on in the paper. Both of the articles discuss the finding of a heart in a dinosaur that when studied challenges a common belief about dinosaurs hearts.
“66 Million–Year–Old Dino With A Heart.” Media Kit 17 April 2000. North Carolina University. 2000 <http://www.dinoheart.org/mediakit/index.html>.
This idea was reinforced when a Diplodocus (a type of sauropod that lived in the late Jurassic) skull was found in 1884 that contained a large hole in the top of the head. Scientists believed that this hole contained the entire nostril (Witmer 2001; ). This positioning of the nostrils was used for many other models of dinosaurs as well, but when it was discovered that...
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
A group of scientists from North Carolina and Oregon used medical technology to search an iron-stained concretion inside the specimen’s chest. With the assistance of imaging equipment and software, they were able to reconstruct 3-dimensional structures through the interior of the concretion. The images reveal a heart that was more like that of a bird or a mammal than those of reptiles, significantly adding to evidence suggesting that at least some dinosaurs had high metabolic rates. In addition, the heart appears to have been four chambered with a single aorta, which is most commonly found in mammals or birds.
The Triceratops was discovered near Denver, Colorado, in 1889. It was discovered by a Paleontologist by the name of Othniel C. Marsh. The first fossil that was discovered was mistakenly identified as an extinct species of Buffalo. A Triceratops skull was discovered in 1888 by John Bell Hatcher. A majority of the fossils were found in North America. Most were found in northern United States, to the Southern parts of Canada. The fossils were in good condition and fairly intact when discovered in Denver.
Mojetta and Discovery Channel had a lot of strong data on prehistoric sharks. The information that was presented in their text gives people knowledge of prehistoric sharks characteristics, time frame they lived in and the remains of these creatures. These bits of information might raise more questions for people about evolution. There have been many different species of prehistoric sharks discovered throughout the years.
...uestion, we will be able to extend research about why humans came from where they did as well as know where to expect the fossil record to lie. Without debates like this one, the research community could lay stagnant, but instead these debates promote new motivations to answer the ever-human desire to know.
The transaction leader differs approach differs from the transformational leader. In general it is motivated by a change taking place. According to McLaurin and Almiri, transactional leadership is a bargaining exchange process between the leader and the follower, lead to the expected or planned outcomes, focus on maintaining the status quo, does not consider the needs of the followers on an individual basis, and the flow of power is more stable than the transformational leader.
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.
In conclusion, transactional and transformational leadership can be merged or used individually depending on various circumstances. However, they are partially correlated. In order to make the best use and get the desirable results out of these principles, leaders should attain a deep understanding of each theory as they are dissimilar in conducting. Moreover, an appropriate balance should be considered if leaders aim to integrate them together. In my point of view, either stand alone or combination usage would benefit to any organizations if the application of leaders was taken in proper situations.