Paleontology
Paleontology involves the inquiry of living things like creatures, vegetations, and further beings that existed in the primitive period, that is, in excess of 5,500 years past. Fossil leftovers of creatures transpire in coatings of sedimentary rock, which develop from the upsurge of dust, rock pieces, sand, and other deposits. The creatures were living when the rocks were in the process of formation. They were obscured and conserved as fossils as the coatings of rock mounded up. (Weishampel 1)
Paleontologists examine fossils to study what sort of existence subsisted at different epochs in World’s olden times. They also observe how the primitive animals and other creatures interacted with each other and what their relation to life is at present. The oldest identified fossils are microorganisms that survived about three and a half billion years in the past. The fossil documentation demonstrates that living things went through a process of gradual to form and develop into their present appearance.
Paleontology is significant in the learning of geology. The period of rocks may be decided by the fossils present in them. Fossils also disclose whether rocks were created under the sea or on land. The majority of rocks that enclose oceanic shell fossils were shaped under the ocean. Generally, rocks that inhibit land animal and land plant fossils were shaped on land or in watercourses and lakes. The acquaintance of where rocks were shaped assists researchers named “Paleo-geographers” plot the earth as it was millions of years in the past. Paleontology also supports the position of oil, which is frequently located in rocks that hold some fossils. (Weishampel 1)
With the specified paleontology’s enormous foretaste, the entire primitive existence, it is improbable that anyone investigator could examine the whole area under discussion in detail. As a result, the subject matter has been classified into focused sub-disciplines or branches.
Micropaleontology
The learning of minuscule fossil creatures, micropaleontology has a diversity of workable functions. Through investigating microfossils, such as plankton or pollen, conserved in sedimentary rocks, professionals in the field provide useful data for oil-drilling operations, characterizing the geology of the extraction area. Microfossils are also used to derive information on ancient climate shifts, which are employed in studies of modern environmental changes. (Gallagher 1)
Paleobotany
Concerned with the anatomy, evolution, and ecology of fossil plants, paleobotany also has industrially important applications, often being utilized to determine the origin and distribution of coal deposits. For example, the study of plant fossils associated with coal beds indicates that most of the large, important coal seams in eastern North America and Europe were laid down in tropical deltas during the Pennsylvanian Period which ranged from 320 to 284 million years ago. (Gallagher 1)
Paleoichnology
Although it is impossible to draw absolute conclusions about dinosaur behavior, credible theories can be advanced based on paleoichnology, the study of trace fossils. For example, sourwood dinosaur tracks in Oxford, England; all headed in the same direction and with varying gaps between the left and right feet, suggest to some paleontologists that these dinosaurs moved about in herds consisting of more than one species of Sauropoda. (Gallagher 1)
Precambrian Paleontology
The formation of the earth started with the commencement of the Precambrian Era, about 4.6 billion years ago, and ended just about 570 million years in the past (or, depending on the source, 540 million years ago), encompassing about 88% of the planet’s history. It was initially believed by scientists that throughout most of the Precambrian, life did not exist. However, this era began to attract greater attention from paleontologists in the late 1940s, owing to the discovery in Australia of a surprisingly large and diverse grouping of fossils left by soft-bodied invertebrates from the late Precambrian. In 1993 the extent of Precambrian life became clearer when the American paleobiologist J. William Schopf reported the existence in Western Australia of bacterial microfossils that were almost 3.5 billion years old. In 1996 the American geological researcher Stephen Mojzsis reported that chemical evidence in rocks found in Greenland may indicate that life existed as far back as 3.9 billion years ago. If Mojzsis is correct, this would prove that earth’s first organisms developed quickly, perhaps just 100 to 500 million years after the planet’s surface had acquired sufficient amounts of water and other materials, such as carbon, hydrogen, and oxygen, to sustain life. (Gallagher 1)
Exopaleontology
A newly rising field, exopaleontology deals with the search for extraterrestrial fossils. Interest in the possibility that living or fossilized organisms might exist within the solar system has been sparked by the discovery on earth of microbes that can survive under extreme conditions of temperature, alkalinity, or acidity and by evidence suggesting that other bodies in the solar system, aside from earth, either have or may once have had environmental conditions hospitable to life. For example, there are indications that more than 3 billion years ago Mars possessed both surface water and an atmosphere containing the elements needed for life to develop. As a result, it has been speculated that if living organisms evolved there, fossilized microbes may exist in the planet’s sedimentary rocks and could perhaps be found with the help of unmanned space probes. (Gallagher 1)
Invertebrate Paleontology
This sub-discipline concentrates on invertebrate animals, that is, those that have no backbone, including worms, spiders, insects, and many marine organisms, such as sponges, coral, jellyfish, mollusks, and sea anemones. A large and diverse group, invertebrates are common in the fossil record.
Many fossilized insects, apparently members of aquatic species, have been preserved in the sediment of lake beds. Often, however, only portions of these specimens, those covered by the hardest parts of the exoskeleton, remain.
In the case of jellyfish or other soft-bodied animals, the organisms themselves did not fossilize; only their imprints, made up of a thin film of carbon formed by tissue decay, have been preserved in rock. Prehistoric plants also were preserved in this manner. (Gallagher 1)
Vertebrate Paleontology
Concentrating on animals that possess an internal skeleton made of bone or cartilage, this field encompasses the study of prehistoric fishes, amphibians, reptiles including dinosaurs, birds, and mammals. The study and analysis of skeletal anatomy, especially using the techniques of cladistics, have yielded new interpretations of evolutionary relationships among vertebrates. Moreover, information about the geographical distribution of prehistoric land vertebrates has helped scientists to determine the sequence and timing of continental fragmentation and biological migrations. (Gallagher 1)
Science and Methodology of Visualizing the Life and Behavior in the Prehistoric Time:
Paleontologist’s performance is mainly base on a number of distinct pieces of evidence. These are as follows:
The Imprints found in the Rocks
Different forms of life leave their imprints concealed in the rocks normally through the process of sedimentation and intermittently due to volcanic commotion also. These imprints can not be considered as fossils technically, while they represent this in the common awareness.
True Fossils
These are the remains of different forms of life, usually the rigid parts like a skeleton or a part of it and the dentures or teeth, in which mineral is replaced with organic molecules.
A diverse progression of the fossilization process takes place with supple tissue while mineral-loaded water blocks up in the gaps usually covered by fluids or gases. This process of mineralization may take place yet at the cellular stage, amazingly parting at the back of the meticulous fossils.
The above-mentioned processes of imprints and mineralization might take very long periods like millions of years to come about. (Paleontology 6)
Preserved Organic Tissue: these kinds of tissues are remains of tiny invertebrates for instance the insects which might have been ensnared in remnant plant resin. However, the organic leftovers of a number of much shortly vanished species, for instance, the mammoths, are discovered in icebergs and swamps.
The Living Fossils
These are referred to as a number of existing forms of life which are presently obtainable. These include some well-known primeval varieties of fish called “Coelacanth”. They are known to have survived for millions of years and they are supposed to look like extended vanished life forms. (Paleontology 6)
Visual Observation
The initial action in examining the fossils is to obtain them except, obviously, the paleontologists decide to study fossils that are previously obtained. All types of fossils are very scarce to find. This is so since the circumstances in favor of fossilization rely on numerous aspects related to one another. For instance, for the mineralization process to occur, there has to be simply the appropriate mixture of minerals and water. Similarly, the progression that allows imprinted fossils, requires merely the precise environmental and biological processes to operate almost immediately subsequent to the expiry of the particular organisms. Therefore, paleontologists search for revealing geological patterns that could direct them to fossil leftovers. Investigation of such geological patterns, identified as topology, can also permit paleontologists to time the fossils. Topology is outmoded at present. It is accepted as “comparative dating” as it was the finest for ascertaining the sequence of fossils formation and not their exact epochs. (Paleontology 6)
The obtained fossils are examined through a number of distinct techniques. On the whole, the evident and most primitive of these approaches is a close examination of the leftovers. This examination may assist the paleontologists to categorize and order the existing structure. Visual observation is also used by paleontologists to study more complicated structures of life by accumulating different parts and recreating the entire being once more. (Paleontology 6)
Investigative instruments utilized during the former sixty years have stimulated paleontologists a long way ahead of straightforward visual observation and relationship of fossils. Conceivably the principal aspect is radiometric timing, specifically, the investigation of the radioactive decomposition that biologically takes place, to an extent, in all constituents or, more exclusively, contained by the radioactive chemical elements imparted in components. Since radioactive isotopes collapse at a precise velocity, that is their supposed partial lives scientists can record the sum of a radioactive isotope in a specified component and understand when it was formed.
Carbon is regarded as the main element of all existing forms of life, thus, in the middle of the 20th century; the decomposition of the isotope carbon-14 became the pivot of scientists’ investigations. Studies established carbon-14 as a valuable pointer for comparatively small episodes of age simply, approximately agreeable for around forty thousand years, showing it compassionate in the research of dinosaurs and even human leftovers but mostly ineffective intended for paleontologists who research in spans of millions of years. Paleontologists shortly determined that metal is found in all living things present on the earth called potassium 40 of a radioactive isotope and it proved to be a model radiometric indicator for paleontologists.
Consistent with present estimations dinosaurs had changeable development rates. They did not develop as quickly as birds or mammals, or as gradually as non-existing avian reptiles. A few of them even now preserved the plesiomorphic stretchy expansion approaches; some further could have developed at a continued speedy rate. This adaptable approach was innate by basal birds, which had in general lesser paces of increase contrasted to present birds known as Ornithurinae, which initiated with the most primitive recognized Cretaceous descriptive, had a quick pace of development with no warning of the capture of bone authentication. Diverse assumptions have developed to give details of this progression change, which is usually envisaged as consequential from modifications in tendencies primarily decline in body volume, almost certainly connected with the flying ability and reproduction capacity. Birds encompass an existing endothermic cluster boldly nested inside the vanished theropods. This is significant in decoding their ecology. ( Dinosaur Paleohistology 1)
Paleontology at Present
During 2003, in northeastern China, paleontologists discovered the fossils of a small, feathered dinosaur with four wings. Named the “micro raptor,” the dinosaur lived between 125 million and 145 million years ago and measured approximately 30 inches about 75 centimeters in length. With two pairs of wings, one set on its forelimbs and the other on its hind legs. The creature may have glided between trees like today’s flying squirrel, and pounced down on unsuspecting prey. Numerous paleontologists believe that birds evolved from some type of small, feathered dinosaur. The micro raptor could represent an important part of the puzzle as scientists try to understand how modern birds came into being. (Castagno 1)
Afterward, in 2003, paleontologists made another remarkable discovery, this time in northern Venezuela. About 6 million years ago, the area was home to one of the largest rodents on Earth. A team of paleontologists, led by Marcelo Sanchez-Villagra of Germany’s Tubingen University, discovered two fossil skeletons of Phoberomys Patterson, an enormous 1,500-pound (680-kilogram), a marsh-dwelling rodent that resembled a giant guinea pig. The fossil skeletons helped paleontologists determine much about the creature, including its size. In addition to its weight, they know the animal was about 9 feet (3 meters) in length, 4 feet (1 meter) tall, and may have used its long tail for balance. (Castagno 1)
Aided by a variety of sophisticated technologies, paleontology has entered a dynamic phase of its scientific development. Stable isotope geochemistry, neutron activation analysis, rare-earth trace element analysis, and other advanced forms of geochemical testing have been applied to paleontological investigations, revealing the age, the environment, and even the diet of prehistoric species. (Gallagher 1)
Computed Tomography to Visualize Dinosaurs
A sophisticated medical tool, the computed tomography (CT) scanner also has become an essential paleontological resource. Used inpatient care, the scanner produces thousands of cross-sectional X-rays, from which it creates a three-dimensional image of a patient’s internal organs.
The same technology also allows scientists to examine the interior structure of a fossil without having to break apart the specimen. For example, a CT scan revealed the complex of tubes and chambers within the bony crest that Parasaurolophus, a dinosaur from the Late Cretaceous Period, bore on top of its skull. Through computer simulation, scientists employed this data to duplicate the sound that may have resulted when the dinosaur blew air through the crest. CT scanning also demonstrated the presence of a four-chambered heart in Thescelosaurus, indicating that this Late Cretaceous dinosaur, and possibly others from the period, were warm-blooded. (Gallagher 1)
Biomechanics
Another valuable tool used by paleontologists is biomechanical analysis, in which mathematical and computer models are employed to re-create the way prehistoric organisms moved. For instance, with the aid of CT scans, a three-dimensional model of a dinosaur skeleton can be drawn on a computer screen. Through examination of muscle scars on the fossil bones and the musculature of present-day animals, muscles and skin can be added to the model and the virtual dinosaur then tested with regard to the range of motion of its limbs and the impact of physical stresses on the bones and joints. Biomechanical analysis is responsible for the recent, and somewhat controversial, theory that the carnivorous dinosaur Tyrannosaurus rex would have been slower on its feet than previously thought and therefore, perhaps, a less effective hunter than paleontologists had once believed.
Cladistics
Since the 1970s paleontologists have increasingly used a classification scheme known as cladistics, in which evolutionary relationships are determined by the number of derived traits (those inherited from a common ancestor) that separate species share. Current paleontological research employs dedicated computer programs to analyze this information. The software utilizes the results of this analysis to build a cladogram, a branching hierarchical diagram in which species are placed in groups, or clades, based on the presence or absence of shared, derived characteristics. Among its more important accomplishments, the cladistic analysis gave rise to the assertion that birds descended from the theropod group of dinosaurs. As though demonstrating the relevance of cladistics in the modern world, in 2007 the fossil skeleton of a large, birdlike dinosaur that lived 70 million years ago was given the name Gigantoraptor. It was uncovered in the Inner Mongolia region of northern China. (Gallagher 1)
Paleontology has experienced an enormous increase in public interest over the past several years. As long as people remain fascinated by life in the ancient past, paleontology will continue to be an active, advancing field of science where new and important discoveries are constantly being made. The most common association with paleontology is, of course, the dinosaur, and dinosaurs have never been more popular. The American Museum of Natural History in New York City and the Carnegie Museum in Pittsburgh has permanent dinosaur displays. The ancient reptiles are featured prominently in movies (such as the Jurassic Park series), documentaries, books, video games, and Internet sites. This popularity has served to attract a new generation of scientists to the field, who have played a vital role in our future by helping us to understand the past. (Castagno 1)
Works Cited
Castagno, Anthony J. “Paleontologists and Their Science.” New Book of Popular Science. 2008. Grolier Online. Web.
“Dinosaur paleohistology: Current state of knowledge”. 2008. Web.
Gallagher, William B. “Paleontology.” Encyclopedia Americana. 2008. Grolier Online. Web.
“Paleontology.” 2008. Web.
Weishampel, David B. “Paleontology.” World Book Online Reference Center. 2008. Web.