The Cenozoic Era Essays

The Cenozoic Era Essays The Cenozoic Era Paper The Cenozoic Era Paper Essay Topic: Equus The Cenozoic Era, which describes the period 65 million years ago (mya) to the present, is a very phase in evolution because it involved the emergence of a variety of species from plants, arthropods, fishes, reptiles and mammals. This era is characterized to have the mammals as the biggest terrestrial animals because the dinosaurs had already gone extinct during the earlier Mesozoic era.   The Cenozoic era is divided into two periods, namely the Tertiary Period, which covers 65 to 1.8 mya, and the Quaternary Period, which ranges from 1.8 mya to the present time.   The Tertiary Period is further subdivided into five epochs. Archaeological findings have revealed that the oldest primate fossils, which were unearthed in Morocco, were dated to be 60 million years old thus placing the emergence of this species in the Paleocene Epoch.    This starts right after the disappearance of the dinosaurs (65 mya) and runs until 53 mya, is characterized by the diversification and multiplication of nocturnal mammals which earlier were hiding from the dinosaurs to avoid predation.   These small nocturnal mammals thus evolved into bigger animals and changed their life cycles from simple night foragers into the diurnal animals.   In addition, the birds, plants and other animal species grew in number because of the absence of the predatory dinosaurs. The early arboreal primate species, or proto-primates, that emerged during this epoch were morphologically similar to lemurs and tarsiers, including the adaptation of hands that were composed of five digits of which one was an opposable thumb.   The proto-primates were small in size, similar to that of squirrels and tree shrews.   These primate species had also adapted stereoscopic vision, large brains and nails to replace claws.   Taxonomical classification of the proto-primates positions them under the genus Altiatlasius. The next primates that emerged occurred during the Eocene Epoch, which runs from 54 to 37 mya.   This epoch is characterized by the emergence of the grass plants that served as a new food source for herbivores.   Such change facilitated the adaptation of grazing mammals such as those of the Equus family in the prairies and savannas.   Flowering plants and trees also started to flourish during this epoch. The proto-primates included the prosimians, such as the lemurs and tarsiers, and these primates started to spread out to the rest of the areas around the world as they further evolved into approximately 60 genera.   Taxonomy has classified these genera into two families, the Adapidae which include the lorises and lemurs and the Omomyidae, for the tarsiers.   The significant diversification of the prosimians must have been due to the absence of competition for resources because the bigger primates did not yet exist at the time.   The prosimians are characterized by large eyes and brains and thin snouts. The bone structure of prosimians show a new structure at the base of the skull called the foramen magnum.   This hole provides a passage for the spinal cord to pass from the brain and this facilitates the position of the entire body, from the horizontal axis, which is observed among grazing animals, to the vertical axis for standing erect (Ackermann RR, 2007).   Due to changes in the climate, the prosimian species decreased in number and reached extinction by the end of the Eocene Epoch. The first species of monkeys then emerged during the Oligocene Epoch, as suggested by fossil records that were collected from the Fayum area in Egypt.   These monkeys are taxonomically classified under the suborders Anthropoidea, Apidium and Aegyptopithecus.   The Oligocene Epoch, which extended from 34 to 23 mya, features the emergence of new mammalian species and the temperature deciduous forests.   The early species of large animals such as the elephants and rhinoceros increased in size and the first primate species such as the monkeys, apes and human emerged. Most of the fossils from ape species come from the Miocene Epoch, thus suggesting the apes evolved from the earlier monkey species (Andrews and Kelley, 2007; Suwa et al., 2007).   The Miocene Epoch, which runs from 23 to 5 mya, is typified by the selection and spreading out of large herbivores such as the cattle and deer.   It is also during this time that the modern horses, deer and birds emerged. The Pliocene Epoch, which extends from 5.3 to 1.8 mya, is characterized by the emergence of the modern mammals and the cooling and drying of the climate just like what is observed in our present time.   The change in the climate resulted into the shrinkage of tropical forests and leaving these only to exist in areas that are close to the equator. Primates follow a certain social structure that is specific to their locale.   Primates have been observed to live in a certain niche and migration is rarely an occurrence.   These species also show some protection towards their area and show aggression if they perceive that another species or primates from other area are attempting to infiltrate their group. Thus, interactions between primates of different groups that live in different areas are not common. Interestingly, chimpanzees are an exception to this primate social behavior because these particular primates tend to be friendly with other primate species that come from other areas or groups.   In the forest, this primate defense behavior for territory is a featured that has been observed by primatologists.   Six social patterns have been described to exist among primates (Chalyan and Meishvili, 2007). These include a single female primate and her progeny, one male primate with several females, a monogamous primate family, a polyandrous primate family, a multi-male and multi-female primate group and a fission-fusion primate group. The monogamous primate family can be employed as a model for our human ancestors because it is composed of a typical human family consisting of a father, mother and children.   Just like humans, the monogamous primate family pattern let their offspring leave upon completion of their development so that they could put up their own monogamous primate family. I would like to design and develop a conservation program to save the great apes of Africa that involves a number of goals.   Firstly, I would like to stop the poaching and exportation of great apes from the tropical forests.   I am aware that the unlawful capture and killing of these apes has been uncontrolled and I would like to establish severe punishment to those who are caught abusing these precious primates.   Secondly, I will propose that a sanctuary be identified and that perimeter fences that are highly sensitive to any human interference will be detected. The jungles of Africa are huge hence there will be a need to employ a large group of people to help out in manning the perimeter of these particular areas.   Thirdly, I would propose that deforestation be stopped because the cutting down of trees in Africa affects the ecological balance of the area.   The decrease in trees will directly mean a shortage of food resources for the great apes.   Thus deforestation influences the great apes to migrate to other areas and this migration may make them more susceptible to capturing and killing (Walsh et al., 2003).