Microraptor: The Missing Link Between Birds and Dinosaurs
In December of 2000, three Chinese scientists reported the discovery of the smallest adult dinosaur ever found, a species that claims to tighten the evolutionary gap between dinosaurs and birds. The dinosaur’s specie name is Microraptor, and it is slowly restoring the integrity of a sect of paleontology that was discredited in November of 1999 after National Geographic printed a story on the discovery of a species known as Archeoraptor. The magazine “trumpeted the story as the ‘missing link’ between birds and dinosaurs,” only for the scientific world and later the public to discover that the skeletal composite built was a, “primitive bird with a dinosaurian tail glued on” (Holden).
The discovery of Archeoraptor was not a total waste of time, however. The dinosaurian half of this faulty species, the tail, in truth actually did help to close the gap between birds and dinosaurs. The tail that was found turned out to be the tail of a Microraptor. The Chinese farmer, who originally discovered the ruins of what came to be known as Microraptor, stumbled across them in the same fossil beds that had housed the remains of inadequate Archeoraptor (Tiny, Feathered). The remains were found in Xiasanjiazi, Chaoyang County in fossil beds composed of layers of rocks known as the Jiufotang Formation, which dates back to the early Cretaceous period, and underlain by the famous Yixian Formation. This formation, “has yielded more than 1,000 specimens of early birds and feathered dinosaurs” (Wang, Xu & Zhou).
Xing Xu, one of the three scientists credited with the discovery of Microraptor bought the specimens the Chinese farmer had found for $5000 (Tiny, Feathered). He then took ...
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...st mistakes of Archeoraptor behind them, those who believe Microraptor to be the evolutionary link between birds and dinosaurs are going to have to prove themselves. With time, tests and evidence it is hoped that Microraptor will help to write a missing part of biological history, answering the questions: What is the evolution of birds? moreover, did the ancestors of arboreal birds once reside on the ground or have they always been in trees? with solid facts.
Works Cited
Holden, Constance. “Florida Meeting Shows Perils, Promise of Dealing for Dinos.” Science Magazine. 288.5464. (14 April 2000): 238-239.
Stokstad, Erik. “Tiny Feathered Dino Is Most Birdlike Yet.” Science Magazine. 290.5498. (8 Dec 2000). 1871-1872.
Wang, Xiaolin, Xing Xu, and Zhonghe Zhou. “The smallest known non-avian theropod dinosaur.” Nature. 408. (2000). 705-708.
Raymond Rogers, David Krause, and Kristina Curry Rogers found significant evidence that the carnivorous dinosaur, Majungatholus atopus, was also a cannibal (Krause et al 2003). The dinosaur remains of the Majungatholus atopus were dated in the late Cretaceous Period from 65 to 70 million years ago. The Majungatholus atopus inhabited the plains of the northwestern Madagascar and bones and teeth continue to be found throughout the Maevarno Formation and within the channel-belt deposits of the Anembalemba Member. The Majungatholus is commonly found, along with other vertebra taxa in ‘bonebeds’ in the Madagascar area, which is probably the reason this dinosaur is still preserved. The trio discovered teeth marks in many bones of the ribs, ilium, and precaudal axial skeleton co...
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.
Dinosaur fossils are one of the few ways in which scientists can study the history of life on earth millions of years ago. Each new discovery is unique in its own way and provides valuable information about the past. No two finds are exactly identical; therefore, when dinosaur remains are uncovered, the possibility and excitement of new information or even a new species exists. Until the year 2000, no dinosaur has ever been found with a fossilized heart. Scientists at North Carolina State University and the North Carolina Museum of Natural Sciences discovered a sixty-six million year old Thescelosaurus with a heart.
In the early 1800’s, a new discovery that left paleontologists in awe was the fossil finding of the immeasurable amount of species of reptiles, Ichthyosaurs. Greek for “fish lizards”, these fossils were found all over the world. Because these large aquatic reptiles migrated just as whales do today, paleontologists have had the amazing advantage of collecting fascinating bone fragments throughout the past 177 years. Ichthyosaurs swam the ocean life from about 245 million until about 90 million years ago- approximately the same time dinosaurs ruled the land. The earliest Ichthyosaur fossil findings were in parts of Canada, China, Japan, and possibly Thailand. Countless fossils came from coatings of limestone produced out of the ocean-floor ooze that was predominantly superior at preserving very well facts of the creatures it digested (Perkins 2).
Matson Museum of Antropology. Penn State college of Liberal Arts. 2011. 1 Aug 2011 .
The chapter of life which saw the rise of the dinosaurs is one of the most fascinating periods in our earth’s history. It is often the subject which brings about young children’s first exposure to science. When these children learn about these intriguing prehistoric beasts, one of their primary inquiries concerns the cause of their annihilation. What could have led to the demise of all those creatures, who lived very successfully for millions of years? This question has plagued experts and curious children alike for decades. In the early 1990s, a “smoking gun” was discovered – purported to solve the mystery of how the dinosaurs met their fate. This discovery was the Chicxulub crater in Yucatan, Mexico. The claim was that this 180 kilometer crater was the impact scar left by an asteroid that collided with the earth. The asteroid was so large and landed with such force that it effectively ended the dinosaurs reign over the earth. However, recent evidence and research reported in Proceedings of the National Academy of Sciences suggests that this could not have been the case, because the Chicxulab crater predates the mass extinction by roughly 300,000 years. Rather, the evidence suggests that two or more impacts caused the mass extinction experienced by dinosaurs.
“...99.9 per cent of all [species] that have ever existed are now extinct.” (Benton 1) After one hundred and sixty million years of domination, the reign of the dinosaurs ended in fire and ice. Sixty five million years ago, the largest volcanoes in the history of the Earth erupted across what is now India, effectively annihilating the dinosaurs by spewing out noxious gas and ash, that effectively blocked out the sun killing off most vegetation and breaking the food chain, leaving the dinosaurs to starve. Compared to other groups of animals the dinosaurs were the most vulnerable to such a climatic event and the result was the end of the dinosaurs’ glorious evolutionary history.
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
This recent discovery has left scientists with many questions to be answered. The discovery is quite important because any research up until now has failed to uncover any evidence that would reveal that dinosaurs fed among their own kind. Ray Rogers whom has been leading the ten-year excavation states in the article that there are at least 14 current day animals that still practice cannibalism such as lions, komodo dragons, crocodiles, hyenas, black bears and grasshopper mice, but in contrast, any evidence of cannibalism among dinosaurs is sparse.
Until recently, scientists believed the chances of finding a fossilized dinosaur heart were extremely slim. The heart belonged to a 66 million year old dinosaur found in Harding County in Northwestern South Dakota. The dinosaur, found in 1993, weighed over 650 pounds and was 13 feet long. The dinosaur was in fairly good condition with the exception of the left side of the skeleton. The small, plant-eating Thescelosaurus, nicknamed ‘Willo’ has been acquired by the North Carolina Museum of Natural Sciences. Thescelosaurus was an ornithischian, or "bird-hipped," dinosaur that lived in the latter stage of the Cretaceous period. This was approximately 1 million years before the end of the dinosaur era. Native to North America, its range extended from the northern United States up into Canada. Since using the 3-D software to reveal Willo's heart, scientists have also used it to create 3-D images of the fossil's skull, and of remains from other dinosaurs in the museum's collection. (Fisher, Paul)
...pdated 1995, accessed 3 Sept. 2000), Dino Buzz – What killed The Dinosaurs ? – Current Arguments,
Solomon Asch (1946) conducted a study to see how people form impressions. Participants were given a set of traits describing a person. The list included Warm, Cold, Polite or blunt (among others). Participants rated the Generosity, Happiness, sociability and popularity (among other words) of the new person.
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.
Instead of seeing students as partially full vessels waiting to be filled, teachers should conceive their work as creating learning situations where students can build their own knowledge through an a...