BC: "My lords, we are vertebrate animals, we are mammalia! My learned friend's manner would be intolerable in Almighty God to a black beetle." -Sir William Henry Maule
FC: Mammals | By: Ameer Awad, Lucy Kool and Olivia Kiklica P5
1: Classification Kingdom Animalia Phylum Chordata Sub-Phylum Vertebrata Class Mammalia Orders: Monotremes, Marsupials and Placental Animals | Characteristics All mammals have a four chambered heart, are endothermic ('warm blooded', meaning they can produce their own body heat), have fur or hair, a four chambered heart, and is fed by their mother's milk. Monotremes, marsupials and placental animals also have specific characteristics, as will be discussed in the next few pages.
2: Monotremes | Monotremes are mammals that lay eggs. There are only two species of monotremes : platypi and spiny anteaters. Spiny ant eaters are covered in spines; when the young are born, they are eggs. The eggs hatch in the mother's pouch and drink her milk. Platypi have webbed feet, fur, and a duck-like bill. They lay their eggs underground in a den. After the young hatch, they feed off of milk that oozes on to the mother's fur.
3: Marsupials are born at a very early stage. They continue to develop inside their mother's pouch. Two types of marsupials are kangaroos (who have strong legs fro jumping, are herbivores, and are found in Australia) and Opossums (found in North America). Opossums can have 21 babies, but the mother opposum only has 13 nipples, so the 13 babies who make it to feed are the 13 who survive. Additionally, opossums are known for hanging from trees and playing dead when danger is near. | Marsupials
4: Placental Mammals Placental mammals are not born until their bodies are developed properly and can function independently. Placenta is the name for the organ that supplies the developing organism with nutrients and removes wastes. Placental mammals vary in their body structure, but usually are put into groups based on how they move and eat.
5: Biomes A biome is an ecosystem that is largely based on temperature (which determines plant life, which determines animal life). Mammals live in many biomes. Below is a list of biomes with an animal example. Marine Biomes: Dolphins and Whales. These creatures have fins so they can swim in the ocean. Freshwater Biomes: River Dolphins. River dolphins also have fins to swim in the water, and a tolerance for freshwater. Mountain and Ice Biomes: Polar Bears and Seals. These animals have fat reserves to survive the cold. Tundra Biomes: Certain foxes, who have hair on their feet to protect them from the snow. Decidious Biomes: These are forests where the trees shed their leaves during winter. Various mammals, including opossums, live here. Desert Biomes: Certain foxes Grassland Biomes: Lions, Wildebeest Tropical Rainforest: Monkeys
6: All mammals reproduce sexually. Some mammals give live birth while others lay eggs. Many young mammals are born without a coat of fur, thus needing their parents to keep them warm. Female mammals feed their young with milk produced in mammary glands. The young mammals are helpless and need their mothers for an extended time. After that, the parent teaches the young mammal how to survive after it becomes a respectful age. Some animals test their children to see if they are ready to live on their own. | Reproduction
7: Type of Symmetry | All mammals have bilateral symmetry. If they have bilateral symmetry it means that they could be split down the middle and look the same on both sides. This can prove to be an advantage for all mammals. Wolves, for example, probably couldn't survive without bilateral symmetry because they wouldn't have two pair of claws or two pairs of legs. That would mean that the wolf couldn't hunt nor could it move.
8: Feeding Habits Energy is one of the things most needed for endotherms to produce their body heat, and that mostly comes from food. Mammals, dividing into carnivorous, herbivorous, and omnivorous groups, have different teeth that aid them to obtain their food, and can help experts identify it's diet. Canines are sharp teeth that stab and tear food. Incisors are flat-edged to help bite off and cut parts of food. Lastly, molars grind food into tinier pieces for digestion. Mammals, like cows, can use their molars to gnash grass and plants apart. Lions can easily hook onto its prey and rip it apart using its canines. These are very important needs for a mammal's obtaining of food.
9: Mammal Era The first mammals to roam the earth appeared about 286 million years ago during the Permian period. They were reptile like, but shared mammalian traits. They became extinct about 160 million years ago. During the Jurassic period, mammals became more common. Nocturnal mammals lived around the time of the dinosaurs, but when the dinosaurs died out 65 million years ago, the first large mammals evolved. They soon adapted to living in different environments.
10: Food Webs | Some mammals eat mammals and others eat plants and grass. The smaller mammals eat other small animals or grass. On the other hand, the larger mammals eat the small animals and sometimes go out in a group to hunt larger animals. The type of teeth mammals have reflect on what they eat, (i.e, a lion). So, if the mammal was a carnivore it would have sharp teeth to eat with. Herbivores, though, have flat teeth for eating plants and leaves, like a giraffe.
12: Fur and Hair | All mammals have fur or hair at some point in their life. Even if it's only a few fairs to being covered in hair. Some animals have fur, which is an adaptation, to help survive in cold regions. hair grows from the living cells located below the surface of the skin. Each hair is made up of dead cells with the same tough material that birds have in their feathers.
13: Getting Oxygen to Cells | All mammals breathe with their lungs. Mammals breathe in and out because of the combined action of the rib muscles and a large muscle called the diaphragm. Lungs have a moist surface area where oxygen dissolves and goes into the bloodstream. Mammals have a 4 chamber heart and a two loop circulation. The first loop moves oxygen poor blood from the heart into the lungs and back to the heart. The second loop takes oxygen-rich blood from the heart to other body parts and back to the heart.
14: The Narwhal (Monodon Monoceros) - Literally, 'Corpse Whale' Narwhals are porpoises that live northwards in the arctic ocean. They are most recognizable for the long horn-like tooth that grows from the males, which can be up to 8.8 feet long. These tusks have given the porpoises the name 'the unicorns of the sea.' They use them to measure changes in their environment. Sometimes the females also grow a tusk, but it is not as prominent. Narwhals are carnivorous, hunting down squid and fish for their meals. They are social creatures; they live in groups of 15-20 though sightings of hundreds have been reported.