Good Example Of Research Paper On Sirenians

Introduction

Arguably one of the strangest animals, the Sirenian has been among the most studied sea animals in modern science. According to scientists, the Sirenian, commonly referred to as the sea cow in layman language, first appeared on earth 50 million years ago (Berta, Sumich & Kovacs, 2006). As a matter of common knowledge, the sea cow is completely aquatic, and lives in a multiplicity of water bodies. It is feared that the Sirenian will soon become extinct, especially considering that most of its closest relatives have walked down the path of extinction. It is an animal that has raised professional curiosity among the sea biologists, environmental scientists and other marine researchers. Worth of note also is the actuality that the Sirenian has made significant appearances in such things as folklore of many cultures. This paper is a detailed report on the evolution, the taxonomic record, the fossil record, the origins and the significance of the Sirenian.

Evolution and Taxonomic Path of the Order Sirenian

The evolution of the Sirenian has been a major topic of research in marine mammology for the sole reason that the information available from the fossil records is scarce and rather inconsistent. Even so, the taxonomic path of the Sirenian is not complicated as its evolutionary path. Primarily, the Sirenian belongs to the Kingdom animalia. The sea cow is a member of the phylum chordata and the large class mammalian. Members of this class portray distinct features, such as breastfeeding their off springs, being warm-blooded and so on. The sea cow belongs to the clade ththytheria and order sirenia. Lastly, it falls under the families: trechechidae and dugongidae. From the study of taxonomy, it is clear that the Sirenian has two genera (trichechus., which has three species, and dugon, which is associated with just one species) the species under trichechus (manatee) are famous inhabitants of the coast of south America, the Atlantic coasts and west African shores. The species of dugon is known to live in the pacific and the Indian oceans.
It is imperative to mention that the sirenians are placental mammals that are believed to have evolved from being terrestrial animals to being completely aquatic (Marshall Cavendish Corporation, 2010). Research indicates that they live in various water bodies, and are not confined to the oceans as was the initial perception. This being the case, sienians can be found in estuaries, rivers, lakes – both manmade and natural – and oceans. Speaking of sirenians and manmade lakes, Lake Volta comes into the picture. The blocking of River Volta to create a manmade lake came as good news for the human population, and devastating news for the aquatic life. The sirenians, ordinarily referred to as sea cows, are divided into two, namely, the manatees and the dugong. They are the only nautical mammals that are known to be pure herbivores, feeding on sea grasses and other flora in the sea floors.
Fossil records indicate that the sirenians made the first appearance on earth approximately 50 million years ago (Berta, Sumich & Kovacs, 2006). While there has been unending arguments about the first appearance of the sirenians, most fossil records indicate that it was between 47 million years and 50 million years ago. The modifications and alterations in the structure of this aquatic animal can be attributed to such powerful factors as oceanographic changes, human interference and climatic cooling. While these factors affect the animals in near equal measure, it is clear that climatic cooling and human interference are the most notable ones when it comes to extinction and decline of the sirenians. Human interference has been the most notable threat to the sirenians in West Africa. The folks are so much interested in the meat of the sirenians that hunting has become so rampant.
The taxonomic path and evolution of the sirenian reveal that the closest relative is the modern day elephant. Taxonomy also shades light on the reality that the sirenians, the desmostylia (now extinct), the proboscidea (the modern day elephants) and the embrithopoda (currently extinct) come together to form what is referred to as tethytheria (Best & Dusi, 2014). This has led to speculation about the connection between the sirenian and the elephant, with some extremists arguing that the sirenian was once an elephant. According to such extremists, the elephant evolved to become an herbivorous sea mammal. Fossil history reveals a lot concerning the appearance of the sirenian. While some researchers and archeologists argue that the first sirenians appeared in the old world. Recent evidence indicates that the first sirenian appearance was observed in Jamaica.
Worth of note is the actuality that, even with the differing opinions on the location of the earliest appearance of the sirenian, all researchers agree on the fact that it was during the early Eocene period. Since that time, many notable structural alterations have taken place, with great diversification being observed. It is critical to mention that, while the diversification took place during the Eocene period, it was during the late stage of the Eocene period. In addition to the diversification, the animals spread widely across the geographical regions of the world. Primarily, the main reason for such spreading is the reality that the sirenian is an inhabitant of many habitats. Foremost, the sirenians live in the seas, the rivers, the lakes, and estuaries. This way, they spread across the world, and today, they are found in virtually all parts of the world – West Africa, the Atlantic coast, the Indian Ocean, the pacific and the key rivers across the globe.
Fossil records show amazing statistics and useful information regarding the evolution of the sirenian. For instance, it reveals that the most primitive sirenian was the prorastomus, which appeared in Jamaica around 47 million years ago. While other researchers differ on the location of the fossils of prorastomus, it is evident that, the skeletal structure found in the Caribbean island of Jamaica is older than the ones found in the new-fangled world as well as those found in the old world. Another important piece of information is that the first and earliest quadrapedal sirenian was the pezosiren, which is also associated with the early Eocene period (Perrin, Würsig & Thewissen, 2009). There are many structural differences between the earliest quadrapedal sirenian and the current ones. For instance, the hind limbs of the modern sirenians have changed to form short bony structures with heavy muscle or the horizontally extended fin used for marine propulsion.
Fossil record also reveals that the first sea cows on record were the size of the modern day pig, with four limbs and other amphibious features. Information available from fossil analysts reveals that the dugongidae first appeared towards the end of the Eocene. From the information, the dugongidae had acquired the adaptive features of marine animals, to enable it cope with the new environment. Primarily, the animal had acquired a flipper-like characteristic around the front limbs. The flipper enabled the animal move swiftly in water. Additionally, the sirenian had begun developing a streamlined body shape, for effortless movement in the marine environment. In furtherance of the movement adaptations, the sirenian developed a powerful tail which had a big horizontal fin that made is easier to propel the massive body of the mammal.
In the late Eocene, the last families of the sirenians, the trichechidae sprouted from the early dugongids. Existing record reveal that dramatic structural changes took place during this period – the late Eocene period. However, it is vital to note that, even though the sirenian has undergone a multiplicity of changes in its evolutionary path, the animal is innately herbivorous. Its evolutionary changes did not alter its eating habits. The only change seen in its diet is shift from eating terrestrial plants to consuming aquatic flora such as the sea grasses and other aquatic angiosperms (flowering plants in the marine environment). The study of fossils reveals that tremendous changes took place in the bone structure of the sirenian (Stamm, 2008). The mammal is a shallow diver which has massive bones. According to marine mammologists, the bones can be described as pachyostotic (significantly swollen) and osteosclerotic (significantly heavy). These features enable the mammal to manage a horizontal position in water. They are also instrumental in helping the animal stay submerged. Evidence of high bone density is acquired from the fossils discovered, especially the ribs.
Among the primary steps that were clear in the evolution of the mammal as it evolved to be completely aquatic, is the development of the tail, which in some species is manifest in short hind limbs that seem to be sunken into the body. The limbs are sufficiently muscular, and can sustain the task of propelling the weighty mammal, which can be as heavy as a ton. Being a warm-blooded animal, the sirenian developed a thick layer of fat, which could help it maintain its temperature in the cold marine environment. This is an adaptive feature in all aquatic mammals, such as the whale. First evolving 50 million years ago, it is not possible to tell the thickness of the layer and the changes it underwent.

The Prorastomus and Its Significance

The term prorastomus sirenoides means “broad front jaws”. The prorastomus sirenoides is presently extinct. It was undoubtedly the most primitive sirenian, which existed in the Eocene Epoch, around 40 million years back in the Caribbean island of Jamaica. prorastomus sirenoides was approximately 5 ft (1.5 meters) in length and had a broad skull structure. Evidence that the mammal was terrestrial is drawn from the actuality that the molars had a crown-like top – a feature common in all herbivores in the terrestrial setting.
The prorastomus sirenoides is exceptionally significant in shedding light on many aspects of the sirenian’s evolutionary path. For instance, it is used as a reference point when studying the structural changes that the animal has undergone. It explains the fact that the sirenian was initially a terrestrial animal (Perrin, Würsig & Thewissen, 2009). For instance, such features as the crown of the molar can be used to explain the terrestrial origins of the modern day sea cow. Lastly, the prorastomus sirenoides is an instrumental reference point when studying the connection between the sea cow and the elephant. It portrays exceptional similarity, which has faded over the years.

Role of Sirenians in Sea-Faring Folklore

Contrary to common misconception that the sea cow is only a subject in marine mammology and other National Geographic Documentaries, the sirenian is a common figure in the folklore of many cultures. Research indicates that Native Americans used the ground powder of the sirenian’s cows to treat earaches and asthma. They believed that the bones of the mammal had strong medicinal characteristics. Simailrly, most West African communites that are inhabitants of the coastline associated it with sacred characteristics according to available literature, West African communities believed that the sea cow was once a human creature, and that killing it was a serious taboo that called for penance. In Ghana, the sirenian, also referred to as the “water mami” is believed to be having some therapeutic capabilities.
Many cultures across the world associate the sea cow with many sea-faring events. For instance, communities from the near east, Europe, asia and Africa believe that the sea cow has some unique powers over other sea creatures. Also, they believe that the sirenian has some spiritual powers that enable it communicates with the human race. Essentially, people from different cultures associate the sirenian with the mermaids. A mermaid is a well-known sea creature that appears in fairy tales and other spiritual tales. People from many cultures believe that the sirenian is the creature that appears as a mermaid. The mermaid tales have their roots in ancient Greece and Assyria.
In ancient Assyria, the people believed that a goddess changed into a mermaid. The goddess, according to legend, was known as Atargatis. Atargatis had accidentally killed her mortal lover (Taylor, 2001). The goddess, in shame and frustration, dived into the water, if only to punish herself for the awful deed she had performed. Upon dumping herself in the sea, she turned into a fish that was half-human. From the waist upwards, she remained human, because, according to folklore, the water could not hide her beauty. From the waist downwards, she was a fish. Some old Greek coins bear an image of the goddess who has a human head and a fish’s body. The people of Assyria usually saw the sirenians and thought it was their goddess.
Christopher Columbus, a known world traveler, reported having seen mermaids on his journey across the world. Considering that Columbus’ tales belong to middle history, it is correct to conclude that until recently, people believed that the sirenians were indeed mermaids. In the 20th and the 21st centuries reports and testimonies of seeing mermaids have been on the news. Some regions have been prominently mentioned in the mermaid cases. Among them, the most pronounced are Canada, Zimbabwe, and Israel. Among the most popular of children’s literature is the old tale Little Mermaid. Written by Hans Christian Andersen, this piece of literature has stood the test of time because it was initially written in the year 1836. Further into Asian folklore, the Babylonian god Ea was a mermaid. The people of Babylon considered the sirenean a holy creature without the knowledge that it was an ordinary animal that they were misconceiving as a spiritually superior being. From the foregoing, it is manifest that the sirenian is an animal that has undergone a multiplicity of evolutions, and bears wondrous significance in many fields.

References

Berta, A., Sumich, J. L., & Kovacs, K. M. (2006). Marine mammals: Evolutionary biology. Boston: Elsevier/Academic Press.
Best, T. L., & Dusi, J. L. (2014). Mammals of Alabama. Tuscaloosa : The University of Alabama Press
Marshall Cavendish Corporation. (2010). Mammal anatomy: An illustrated guide. New York: Marshall Cavendish.
Perrin, W. F., Würsig, B. G., & Thewissen, J. G. M. (2009). Encyclopedia of marine mammals. Amsterdam: Elsevier/Academic Press.
Perrin, W. F., Würsig, B. G., & Thewissen, J. G. M. (2009). Encyclopedia of marine mammals. Amsterdam: Elsevier/Academic Press.
Stamm, D. R. (2008). The springs of Florida: Text and photographs. Sarasota, Fla: Pineapple Press.
Taylor, J. (2001). Petra and the lost kingdom of the Nabataeans. London [u.a.]: I.B. Tauris.