Transitions Of Reptiles To Mammals Essay

2603 words - 10 pages

a long boring read, lots of techno words needs work on footnotes and referencesTransitions of Reptiles to MammalsA long long time ago, in a galaxy not too far away, was a little blue planet calledEarth, and on this world not a single mammal lived. However a lot of time has past sincethen and we now have lots of furry creatures that are collectively called mammals. Howdid they get their? Where did they come from? These are the kinds of questions that ledme to my subject of choice. I will endeavor to provide examples, using specifictransitional fossils, to show that mammals have evolved from a group of reptiles and weresimply not placed here by unknown forces.Before I begin, I would like to define some terms so that nobody gets left in thedust. The term transitional fossil can be used in conjunction with the term generallineage, together they help explain the how one species became another.'General lineage':This is a sequence of similar genera or families, linking an older to a very different youngergroup. Each step in the sequence consists of some fossils that represent certain genus orfamily, and the whole sequence often covers a span of tens of millions of years. A lineagelike this shows obvious intermediates for every major structural change, and the fossilsoccur roughly (but often not exactly) in the expected order. However, usually there arestill gaps between each of the groups. Sometimes the individual specimens are not thoughtto be directly ancestral to the next-youngest fossils (e.g. they may be 'cousins'' or'uncles' rather than 'parents'). However they are assumed to be closely related to theactual ancestor, since the have similar intermediate characteristics.-1-Where Does It All Begin ?Mammals were derived during the Triassic Period ((from 245 to 208 million yearsago) It began with relatively warm and wet conditions, but as it progressed conditionsbecame increasingly hot and dry.) from members of the reptilian order Therapsida. Thetherapsids, members of the subclass Synapsida (sometimes called the mammal-likereptiles),generally were unimpressive in relation to other reptiles of their time. Synapsidswere present in the Carboniferous Period (about 280 to 345 million years ago) and are oneof the earliest known reptilian groups. Although therapsids were primarily predators bynature, some adaptations included a herbivorous species as well, they were generally smallactive carnivores. Primitive therapsids are present as fossils in certain Middle Permiandeposits; later forms are known from every continent except Australia but are mostcommon in the Late Permian and Early Triassic of South Africa.The several features that separate modern reptiles from modern mammalsdoubtlessly evolved at different rates. Many attributes of mammals are correlated withtheir highly active lifestyle; for example, efficient double circulation of blood with acompletely four-chambered heart, anucleate and biconcave erythrocytes (blood cells), thediaphragm, and the...

Find Another Essay On Transitions of Reptiles to Mammals

evolution of reptiles Essay

1508 words - 7 pages a protective environment in which the embryo can develop and enables reptiles to lay their eggs in dry environments. On the other hand, amphibians must lay their eggs in or near water. The reptilian skeleton differs from other vertebrates in many ways. For example, reptiles have many bones in their lower jaw to enable them a greater bite mobility, but mammals only have one bone in their lower jaw called the mandible. Mammals ears consist of three

Warm Blooded Or Cold Bloded Essay

668 words - 3 pages Dinosaurs, like other reptiles, were thought until fairly recently to be cold-blooded. There is still a good case for this viewpoint. But lately some scientists have swung to the idea that dinosaurs were warm-blooded. There is a good case for this too. Scientists have conflicting opinions on this subject. Some paleontologists think that all dinosaurs were "warm-blooded" in the same sense that modern birds and mammals are: that is, they had rapid

Extinction

1174 words - 5 pages because they all died! All animals die, but extinction happens because lesser new are born than die.The dinosaurs were a very great success and the superiors of their time with no competition from other vertebrates. The mammals, which did exist during the entire dinosaurian period, were small nocturnal animals, which played only little or no role to the dinosaurs.At the beginning of the Triassic various other groups of reptiles, which had survived

The Once Pristine Idyllic Wetland is Now a Garbage Dump

620 words - 3 pages watchers opine that the number of bird species sighted in the wetland is definitely more than in the Vedanthangal bird sanctuary. The heterogeneous ecosystem of the marshland supports about 337 species of floras and faunas: GROUP NUMBER OF SPECIES Birds 115 Plants 114 Fishes 46 Reptiles 21 Mammals 10 Amphibians 10 Molluscs 9 Butterflies 7 Crustaceans 5 Total 337 Birds, fishes and reptiles are the most prominent of the faunal groups. Russel's

Religion vs. Science

1007 words - 4 pages . Birds, which, according to both creation myths in Genesis, "were created on the same day as fish,"(Genesis) do not enter the fossil record until the Jurassic Period "190-136 million years ago"(Encarta). Representing an ultimate variation on the dinosaur theme, birds trace their descent from reptiles. This is quite different from those ancestral to the mammals. Contrary to the claims of some creationists, evolutionists do not claim that reptiles

A brief History of Life on Earth

521 words - 2 pages continents slowly moved northward. At the end of the Devonian there was another 75% mass extinction of all marine life due to climatic circumstances. The Carboniferous (354-290 mya) brought large amounts of glacial formation on Gondwana. Terrestrial animals diversified and some of the first reptiles appeared during Carboniferous period. During the Permian period (290-245 mya), all of the continents came together to form the super-continent Pangaea

What is the evidence for the thory of evolution?

530 words - 2 pages the fact that dinosaurs that lived 150 millions of years ago that suggest that they are related to crocodiles. Also certain fossils have been found that are similar to both reptiles and mammals. This suggests that they were the animals that created the first mammals.Although all of this evidence is not absolute proof, it is still very strong evidence that the theory of evolution is true.

The classification of reptiles

794 words - 4 pages consists of the alligators, caimans, and the gavial idea family. Crocodilians are a solid massive lizard like reptile, they have long flattened snouts, and compressed tails. Crocodilians are elite swimmers and can also move on land in a “High or Low walk” some smaller species can even gallop. These reptiles have a four chambered heart that is somewhat similar to birds, and have a unidirectional looping system of airflow within the lungs. In the

The Green Anole (Anolis Carolinis): Physique, mating, and needs. Small reptile care

605 words - 2 pages Reptiles manage to endure as one of the most fascinating types of creatures on earth. One of the most commonly found reptiles in southern United States is the Green Anole, or Anolis Carolinis. The life of one of these unique creatures comprises of numerous intriguing physical properties, interesting mating behavior, and invigorating physical needs.Overall, the physical characteristics of a Green Anole interest many. Out of over 300 species of

Dinosaurs are Awesome

663 words - 3 pages time period and before the Tertiary. This is a time when dinosaurs were at their height with many thousands of different species known or yet to be identified. Our earliest ancestors were small rodent-like mammals that lived during this time and gradually evolved into the many different types of mammals we see today. The dinosaurs though, would become small reptiles such as the lizards we see today after one of the greatest known extinctions of

Human Origins

2113 words - 8 pages different taxon because birds and dinosaurs share a feature of the pelvis not found in any other group, including reptiles.” Earlier, on (pg 95), they are discussing transitional forms of fossils and use in parentheses the clarification “dinosaurs to birds and reptiles to mammals”. These two statements imply very different definitions for the term “reptile”. First of all, “reptiles” as commonly defined is not a monophyletic clade. In order to

Similar Essays

Transitions Of Reptiles To Mammals Essay

2568 words - 10 pages Transitions of Reptiles to Mammals      A long long time ago, in a galaxy not too far away, was a little blue planet called Earth, and on this world not a single mammal lived. However a lot of time has past since then and we now have lots of furry creatures that are collectively called mammals. How did they get their? Where did they come from? These are the kinds of questions that led me to my subject of choice. I

Response Of Marine Mammals To Anthropogenic Nose

1208 words - 5 pages lethal injury in marine mammals has received considerable attention in the scientific and public spheres. Routine anthropogenic sounds in the underwater consisting of seismic surveys, pile driving or chemical explosions; leads to extensive disturbance of normal behaviour by marine mammal species (Department of Arts, Heritage and the Gaeltacht, 2012). Marine mammal exhibits diverse impacts are including: changes in vocalisations, behavioural

A Journey Through Evolution The Locomotion And Behavioral Changes Of Fishes, Reptiles, Amphibians, Birds And Mammals. A Good Starting Place For Short Biology Papers

2071 words - 8 pages This is a huge area of discussion, therefore, you must be very selective of your topic, and write succinctly and to the point. For example, you may want to choose the theme of "reproductive strategies" of fishes, amphibians, reptiles, birds, and mammals, or you may choose "locomotion", "environmental adaptations", etc etc etc - the list is endless. I am interested in reading your specific interest in evolutionary biology.Throughout the millions

Types Of Animals On Earth Essay

1320 words - 6 pages . Animals that roam the Earth are classified into three major categories, namely mammals, reptiles and amphibians, where each category is further divided into their respective orders (refer to Figure 1 in Appendix 1). The first major type of animal is mammal. There are more than 4,000 different species of mammals. The smallest is the hog-nosed bat, which weighs 0.05 ounces. The largest is the blue whale, which can be 100 feet long and weigh 150