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.
The difficulty in re-constructing dinosaurs for television and movies lies in the fact that not everything can be preserved. Fossilized bones create the skeleton of a dinosaur, thereby allowing scientists to study how they moved, how big they grew, and how different body parts worked as a whole. But what children see on television: the scaly green skin of the brontosaurs or the brown hair of a mastodon may not hold much fact. Unfortunately, particular physical features cannot be fossilized. Skin, cartilage, hair and other soft tissues usually decay before leaving science no clues to what these dinosaurs truly looked like. The public also cannot know the social behaviors of dinosaurs. Movies generally portray all carnivores like the T-Rex as monstrous bullies while the larger vegetarians all seem slow and peaceful. Up until recently, no hard evidence can be found to help support or dismiss any of these stereo-types. In the barren deserts of Argentina, a team of scientists from the National Geographic Society came across a massive graveyard of fossilized dinosaur eggs. In 1997, Dr. Luis Chiappe and Dr. Lowell Dingus discovered a rare opportunity to finally study the external functions of an ancient creature that contained fossilized teeth imprints, embryos and skin impressions. This unearthing unlocks endless prospects to learn about dinosaur behavior and external attributes, topics which used to be some of the most problematic areas of study. The most remarkable aspect, of course, is how the most delicate of information is found within an egg.
At a time, scientists believed all dinosaurs were cold-blooded. However, with a recent discovery of a dinosaur found with a fossilized heart in the northern part of South Dakota in 1993, many paleontologists are starting to think that there were some dinosaurs that were warm blooded.
Borkowski (2015) distinguished between transactional leadership and transformational leadership by explaining that: transactional leadership is directed toward task accomplishment and the maintenance of good relations between the leader and subordinates throw consideration of performance and reward. And, Transformational leadership, contrasting transactional leadership, is directed toward the influence and management of institutional change and innovation through revitalization and
Xu, X., Zhou, Z., Prum, R.O. 2001. Branched integumental structures in Sinornithosaurus and the origin of feathers. Nature 410: 200-203.
Every so often a discovery is made that attempts to shake up pre-conceived notions of how the dinosaurs actually lived or how they came to be. On June 22, 2000, in Oregon, scientists announced the discovery of the oldest known animal to have feathers. Though no records indicate how the age of the animal was determined, the fossil was dated at 220 million years old. It lived at the time of the very earliest dinosaurs, and about 75 million years before the first known bird.1[1]
Where should the nostril on dinosaur models be placed? Although it seems like a rather simple question, it is a topic that has been recently researched so that scientists can feel reassured in creating anatomically correct models of dinosaurs. Amniotes (a group which in the Triassic spilt into reptiles and synapsids and which include dinosaurs), have large nasal openings, but since the nostril is made up of flesh and cartilidge, it is almost always not preserved in the fossil record (Lauren and Gauthier 1996). These were often huge in dinosaurs, such as the sauropods, hadrosaurines, and ceratopsids, so that there are several places in which the nostrils could be placed. For many years, scientists have placed the nostrils on dinosaurs in the caudal position, which is located on the top of the head. The nostrils were placed in this location because it was thought in the mid nineteenth century that sauropods lived in water (Clarke 2001). This was believed because at the time, palenotolgists thought that sauropods probably weighed several tons, and that the animals could not have supported themselves on land (Rincon 2003). It was believed that having the nostrils in this position would help the dinosaurs to breathe easily, instead of having to lift their heads completely out of the water (Clarke 2001).
If we compare these two types of leadership, we can see that they have many differences. Firstly, transactional leaders appeal to the self-interest of employees who seek out rewards for themselves, in contrast to transformational leaders, who appeal to group interests and notions of organizational success. Secondly, transactional leaders work within an organizational culture, while transformational leaders make new ideas and therefore "transform" organizational culture. Thirdly, transactional leadership reacts to problems as they arise, whereas transformational leadership is more likely to address issues before they become problematic. Finally, transactional leaders reward and punish in traditional ways according to organizational standards; transformational leaders attempt to achieve positive results from employees by keeping
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.
According to Yoder-Wise (2015), a leader can be defined as, “an individual who works with others to develop a clear vision of the preferred future and to make that vision happen” (p 35). As employees, we often have our own ideal of a good leader, which may be influenced by experiences and perception of workplace norms. While one’s opinion of an effective leader may vary, there are several recognized leadership theories. The following will focus on the transformational leadership approach.
...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.
According to our text book there are two main classifications of leadership approaches, transformational leadership and transactional leadership (Yoder-Wise, 2011). Transformational leadership is centered on motivation and building relationships with staff through a shared vision and mission (Frandsen, 2013). Transactional leadership approach involves one superior with minimum or no input from the employees (Yoder-Wise, 2011).
The crocodilian is an order of a large predatory semiaquatic reptiles who have been around for millions of years. Roughly around 83.5 million years ago is when the crocodilian first appeared, the crocodilian family consists of the alligators, caimans, and the gavial idea family. Crocodilians are a solid massive lizard like reptile, they have long flattened snouts, and compressed tails. Crocodilians are elite swimmers and can also move on land in a “High or Low walk” some smaller species can even gallop. These reptiles have a four chambered heart that is somewhat similar to birds, and have a unidirectional looping system o...
Transformational leadership is an extension of transactional leadership. Organization should maintain base of transactional leadership while moving their organizational culture towards one of Transformational qualities.
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.
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.