Extinction gets certified when there is no surviving individual that is able to create a new generation through reproduction. Functional extinction describes this state where only a countable few specie members survive, and can neither thrive nor reproduce. This could be as a result of age, lack of representation of both sexes and poor health and distribution. The actual point of extinction is difficult to identify due to the larger potential range that a species has, and the determination of extinction is usually done retrospectively.
Dinosaur is a term that gets used to refer to a wide variety of chiefly terrestrial, carnivorous and herbivorous reptiles of the now extinct Ornithischia and Saurischia orders that thrived during the Mesozoic Era. They are thought to have been the biggest known land animals that shared a specific common anatomy. True dinosaurs had legs ankles and hips somewhat structured like a bird’s, such that the legs were mobile under the body and not outside like present lizard species. Sir Owen Richard formed the name dinosaur in 1841 to identify the remains of extinct reptiles. The name dinosaur originated from the Greek word deinos which means fearfully terrible, and sauros, which means lizard.
Many explanations have been given, some of which have been convincing, about the extinction of dinosaurs. These explanations range from disease, volcanic eruption, asteroid impact, and climate change, which is the most supported of all theories (Page 56). II CASE PRESENTATION A. ASTEROID IMPACT THEORY The Asteroid Impact theory gets used by many scientists to explain the disappearance of dinosaurs from the face of the earth. As such, several variations of this theory exist, some of which are largely similar with minor differences setting them apart. The asteroid extinction theory gets sometimes referred to as the K-T Asteroid Theory, and the Alvarez Asteroid Impact. All these theories vary marginally, but are all centered on a single event though to have prematurely destroyed most of the life forms on earth dating back 65 million years ago (Norman 77). The asteroid theory got first fronted by the father son team of Walter and Luis Alvarez in1978. Walter and Luis analyzed sediment samples collected in the 1970s at the K-T layer close to the town of Gubbio in Italy. The tests revealed high concentrations of the element Iridium, rarely found on earth, but found in abundance in meteorites. Upon analysis of more sediment of K-T boundary strata from other regions of the globe, high concentrations of Iridium got recorded, as well. Guided on the basis of the average sediment thickness, team Alvarez suggested that a large comet or asteroid, perhaps several miles in diameter would be needed to spread as much Iridium as was recorded all over the earth. The impact of such an asteroid hitting the earth would be a massive explosion, massive fires and total annihilation of whatever life existed then, dinosaur inclusive (Parsons 95). A crater, partly submerged in water and worn down, got found along the Mexican Yucatan Peninsula whose creation largely coincides with the K-T boundary. Scientist from the world renowned National Aeronautics and Space Administration estimate that the Chicxulub Crater as it is currently known would have gotten formed as a result of the action of a 6 to 12 mile diameter asteroid. The crater is currently about 130 miles wide (Debus 66). Scientists from the Southwest Research Institute in Colorado have traced the asteroid path back into space. Their calculations revealed that a collision between an asteroid that was 100 miles wide called Baptistina, and another asteroid of relatively small size out beyond Mars’