Classification Of Mammals
What are Mammals?
Mammals are vertebrates (backboned flora and fauna) that feed their young on mother's exploit. There are approximately 4,260 species of mammals.
When we think of an creature it is likely to be a mammal. People are mammals. Cats and dogs are mammals. So are such ranch animals as cattle, goats, hogs, and horses. Mammals also include such captivating animals as porcupines, gorillas, giraffes, rhinoceroses and kangaroos.
Mammals are found to be present all over the world in all different climates. Mammals such as chimpanzees and elephants inhabit in tropical regions. frosty foxes, polar bears and many other mammals make their home near the north pole. Camels and coyotes live in deserts. Some mammals even live in the sea such as dolphins, seals and whales. One group of mammals, the bats, can take off.
Evolutionary Perspective
Tertiary period started about 70 million years ago. It was the start of the "era of mammals". It produced adaptive emission in the mammals. Extinction of many reptilian lineages also persent in this period.
1.Evolution of pelycosaurs
Mammalian characteristics evolved gradually over a period of 200 million years. The early synapsids were the pelycosaurs. Some of them were herbivores. The others were predators. Thay showed skeletal adaptations for voracious life.
1. Evolution of therapsid
Some other mammal like reptiles arise from the pelycosaurs by the center of Permian period known as therapsid.
• Predator therasids: some therapsids were predators, their teeth were intense at the front of the mouth, they had engorged teeth for holding and tearing the kill.
• Herbivore therapsids: The teeth of herbivores were also mammal like. Some had large gap called diast...
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...rs ago, they diversified, leading to the three major groups of today: monotremes (Prototheria, including the platypus, echnidna, and extinct relatives), marsupials (Metatheria, including kangaroos, koalas, and many obscure living and extinct forms), and placental mammals (Eutheria, including mice, elephants, whales, and humans, among many others).
Theria
Theria is derivative from a Greek word meaning wild beast,it is a subclass of mammals that give birth to live young without using a shell egg, consisting of the eutherians (as well as the placental mammals) and the metatherians (including the marsupials). The only misplaced extant mammal group is the egg-laying monotremes.
The initial known therian mammal fossil is Juramaia, from the center Jurassic of China. However, molecular data suggest that therians may have originate even earlier, during the Early Jurassic.
...silophodon, a small, agile bipedal herbivore. The Ceratopsians appeared at beginning of cretaceous period from the family Ornithopoda. Pachycephalosaurs contained a ten inch thick skull, which was actually fairly fragile, and their first line of self defense would be to run away. Ceratopsians, which mean horned face, are large beasts with horns that can defend themselves pretty well. Both were very similar, but contained distinct differences.
The relationship of the three species and their ancestors can be summarized by looking at the fossils above. It is evident that all of these three species possess fangs and other types of sharp, prominent teeth. These analogous features indicate that there is some similarity in ancestry, since they all form part of the same family group, although they come from different genus. However, there is some difference in the shape of the head. The coyote possesses a straighter jaw and more angular head. The wolf, on the other side, has a wider denture similar to the fox. These three species also share Homologous structures, such as fangs, are present in these species. Another homologous structure is the legs and ribs, since they all have a similar
1.A lot of people are misinformed, have misconceptions, or might not have any idea at all about what these animals are about. The ferret family, which includes weasels, mink, polecats, martins, skunks, badgers, otters, wolverines, and the endangered black-footed ferret. Early Greek literature suggests that unlike its cousins, the ferret has been domesticated for approximately two to three thousand years.
: Primates didn’t just appear among Earth, but they evolved. The coevolution has to do with flowers and fruits. Fruits were evolving to get tastier for primates to eat and as primates ate them they spread them around as well. As they ate these new evolved fruits and flowers this invited changes onto their bodies as
Their dorsal fin is extremely long, tampered and pointed in a triangular shape or rounded and curved towards the end. The skull is oval shaped and the beak is extremely short and rounded at the end. The killer whale’s jaw is powerful with teeth that are able to tear apart flesh of their prey. They can withstand the jolting, wiggling and hurtling movements of prey that are trying to escape. The killer whale is born with a single blow hole instead of two. Their flippers are paddle shaped with rounded ends and flukes are tapered back and pointed at the end resembling to a triangle/pyramid
The descendants of the first radiation of mammals, monotremes have characteristics of both placentals and marsupials, while still retaining characteristics of reptiles and birds in a combination all their own. Introduction At first glance, platypuses seem to be an amalgamation of mammals, birds, and everything in between. In fact, their reproduction biology also has much in common with a variety of animals—reptiles, birds, placentals and marsupial mammals. Platypuses belong to a group of animals called monotremes. These egg-laying mammals have been a mystery to researchers since their discovery by Westerners over 200 years ago.
Mountain building and climate changes happened often in this period, as well as the breakup of Pangaea. Mammals were very popular and they were very different and everywhere. The climate was much colder now. The animals adapted to their environment and diets; meat eaters had sharp teeth for cutting and ripping, rodents had self-sharpening front teeth for gnawing and plant eaters had molars for grazing plants.
Hippopotami belong to a group of animals called artiodactyls. This group of animals, which includes deer, camels, sheep, pigs, and cows, are “named for the even number of fingers and toes...
The Jurassic period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 millions years ago, following the Triassic Period and preceding the Cretaceous Period. During the Jurassic Period, the supercontinent Pangaea split apart. Laurentia, the northern half, made up what would eventually form North America and Eurasia. The creation of these opened basins for the central Atlantic and the Gulf of Mexico. The southern half, Gondwana, drifted into an eastern segment that now forms Antarctica, Madagascar, India, and Australia, and a western portion that forms the present Africa and South America. This rifting, along with generally warmer global temperatures, allowed for diversification and dominance of the reptiles known as dinosaurs. Along with dinosaurs, several different types of life and rock formations emerged during the Jurassic period.
good source of food. The Trilobites fought back for a time, growing spines during the
...nder, C., Tsai, C., Wu, P., Speer, B. R., Rieboldt, S., & Smith, D. (1998/1999/2002). The permian period. Informally published manuscript, Biology 1B project for Section 115, University of California Museum of Paleontology, CA, Retrieved from http://www.ucmp.berkely.edu/permian/permian.php
The Triceratops were very interesting dinosaurs. They were very smart and strategic. They moved in herds and used mating calls. They were very complex. They had an interesting body shape that gave them an advantage towards their predators. They were known for their horns and parrot-like beaks. They were herbivores that lived in North America. Triceratopses were very interesting.
All primates have essentially the same kinds of specialized mammalian teeth adapted to eating a wide variety of foods. Beginning at the front, each quadrant of the mouth has 2 incisors, 1 canine, and varying numbers of premolars and molars. The incisors are used like scissors for nipping off pieces of food. The pointed canines are for piercing and tearing. The premolars and molars, with their cusps, are used to grind and smash food. In platyrrhine species, there are 3 premolars and 2 or 3 molars. This results in a dental formula of 2.1.3.2 or 2.1.3.3. In contrast, all of the catarrhines have 2 premolars and 3 molars, making a dental formula of 2.1.2.3. The chimpanzee shown below is an Old World anthropoid species and, therefore, has a catarrhine dental formula.
The fossil record of horses extends back to an odd-toed ungulate mammal belonging to the taxonomic family Equidae, a dog-like ancestor 55 to 42 million years ago in the genus Hyracotherium in North America. Hyracotherium had a primitively little face , four-toed forefeet, three-toed hind feet, an arched back, small brain, and higher hindquarters than forehand. Later genus has increased in body size, brain complexity, the size of cheek teeth, lengthening of the face, and reduction of toe number. However, even though horses got larger over time but these trends are not seen in all of the horse lines. Genus such as Hipparion existed from 23 to 2 million years ago, showed gains in size, But some later genus such as Archeohippus, and Calippus got smaller again (Boundless, 2016),(Encyclopedia of Life,2015), (equineworld.co.uk, 2014), (Molen, M.