While there is no direct indication of the Tyrannosaurus rex having had feathers, scientists now consider that the T. rex had feathers on at least parts of its body. Because of their presence in related species. Mark Norell of the American Museum of Natural History stated with evidence "we have as much evidence that T. rex was feathered, at least during some stage of its life, as we do that australopithecines like Lucy had hair." The first evidence for feathers in tyrannosauroids came from the small species Dilong paradoxus, found in the Yixian Formation of Chinaback in 2004. As with many other theropods uncovered in the Yixian, the fossil skeleton was preserved in a shell of filamentous structures which are commonly known as the precursors
The respiratory system is the system for taking in oxygen and giving off carbon dioxide in organisms. The respiratory systems of California sea lions, king cobras, and bald eagles have a few similarities and differences, but they all allow the intake of oxygen for each organism.
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...
The Feather Pillow written by Horacio Quiroga is a very touching story. The story contains a female who seems to be in love with her husband. The female seemed to not feel conformtable at home though, she mentioned that her husband gives her chills. She narrates the story as if he husband controls her life and she has no freedom.
The reading states that critics have opposes the idea that Sinosauropteryx was a feathered dinosaur and the author provides three reasons of support. However, the professor explains that critics are unconvincing and refutes each of the authors' reasons.
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.
... over the print is correct. All of these facts are bittersweet though, since sample specimens have nothing to be compared to since no actual creature specimen has been collected. It can be concluded, however, that these remains did not come from any animal currently known to modern science.
Majungatholus atopus roamed the plains of northwestern Madagascar about 70 million years ago during the Late Cretaceous (Perkins, 2003; Rogers et al, 2003). The discovery of 21 tooth-marked elements originating from two Majungatholus atopus individuals suggests evidence that the dinosaur supplemented its diet by feeding on its own dead or hunting them (Rogers et al, 2003). It cannot be confirmed whether they were purely scavengers, hunters, or both. Scientists are certain that the marks are not the doing of any other predator because the teeth marks are not consistent with any other known species that lived in the area. Only one other theropod that inhabited the area during the time Majungatholus atopus did, Masiakasaurus knopfleri, had teeth and bite marks too small to have caused these markings. Two large crocodile species also shared the same ecosystem but their teeth were “too blunt and too irregularly spaced to have produced the narrow grooves found on the Majungatholus bones”(Perkins, 2003). The tooth marks on at least nine Majungatholus elements attest to intertooth spacing in the perpetrators jaw and denticle drag patterns consistent enough to make a compelling case for Majungatholus feeding on other Majungatholus (Rogers et al, 2003).
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.
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...
...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.
John Updike’s poem “The Great Scarf of Birds” expresses the varying emotions the narrator experiences as he witnesses certain events from nature. His narration of the birds throughout the poem acts as numerous forms of imagery and symbolism concerning him and his life, and this becomes a recollection of the varying emotional stances he comes to terms with that he has experienced in his life. These changes are so gradually and powerfully expressed because of a fluent use of diction and figurative language, specifically symbolism and simile, and aided by organization.
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.
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.
With its abundance of genera, the Burgess Shale is one of the world’s most important fossil fields. It’s discovery in 1909 led to over 100 years of paleontological study in the Canadian Rockies, a majority of which has been carried out in two quarries known as the Walcott and Raymond quarries (Hagadorn, 2002). Though he was originally in search of trilobites in the Burgess Shale Formation, paleontologist Charles Walcott also discovered a diverse group of soft- and hard-bodied fossils, from algae and sponges to chordates and cirripeds (Hagadorn, 2002). Soft-bodied fossils are incredibly rare due to their delicate structure and susceptibility to decay, so it is hard-bodied fossils that more regularly occur in fossil findings. However over 75,000 soft-bodied specimens have been found in the Burgess Shale formation (Hagadorn, 2002). These specimens are preserved in layers of shale formed from deposits of fine mud. One of the most significant species discovered is the Pikaia gracilens. Believed to be an early chordate, the Pikaia gracilens existed very close to the beginning of the evolutionary path that ultimately lead to humans (McGraw-Hill Encyclopedia, 2006).
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.