Mammal Hair Mammary gland Diaphragm Monotremes Marsupials Eutherians Placenta Oviparous Gestation period	Teeth Enamel Dentine Pulp cavity Cementum Root canal Viviparous Respiratory system Digestive system Circulatory system	Urogenital system Crown Root Incisor Canine Bicuspid Molar Antler Horn

TheMammals

Mammal characteristics:

Hair
Mammary glands
specialized sweat glands located in the thorax or abdomen that produce milk to nourish the young.
Heart is 4-chambered
Breathing diaphragm -
a curved sheet of muscle below the rib cage. Contraction of the diaphragm during inhalation helps draw air into the lungs.
Viviparous
Endothermic

Game Ranger

See where mammals fit into Earth's history. The Class Mammalia is divided into roughly 26 Orders. Dichotomous key for mammal identification.

3 reproductive strategies in mammals:

Egg-laying mammals, the Monotremes
Oviparous, egg-laying mammals.
The female curls around the eggs to protect and incubate them.
Although females have mammary glands, the glands do not have nipples.
Duck-billed platypus and spiny anteater, neither are native to North America.

Pouched mammals, the Marsupials
Viviparous mammals, giving birth to live young, but the young are born very prematurely. They make their way into the pouch where they attach to a nipple and continue to develop. The picture shows 18 new-born opossums held in a teaspoon.
The Opossum in North America.
Nearly 250 other species in New Guinea, Tasmania, and Australia.

Placental mammals, the Eutherians
Viviparous mammals, giving birth to well developed young that have been nourished by a placenta in the uterus of the female.
The most successful group, making up 95% of all mammal species.
Every mammal native to the United States is a placental mammal, except the Opossum.

Gestation period:
Time of development in the placenta.
The period between fertilization and birth.

Gestation period for some mammals
Animal	Gestation (Days)
Mouse	19
Rabbit	31
Dog	61
Cat	63
Pig	112
Goat	151
Deer	201
Cow	284
Horse	330
Asian Elephant	645

Mammal teeth:

Mammal teeth are highly specialized. Examining the teeth can tell you a lot about the habits of the animal. While the shape, size, and numbers of teeth differ from one species to another, all mammal teeth have the same basic structure:

Enamel - a hard, smooth covering to protect the crown. Dentine - the porous, bone-like foundation of the tooth. Pulp cavity - contains blood vessels and nerves. Cementum - the material that "binds" the enamel to the dentine. Root canal - the canal through which blood vessels and nerves reach the body. The crown of a tooth is located above the gum. The root of a tooth is located below the gum.

Although some species are lacking a particular type of tooth, there are four types of teeth.

Incisors - knife-edged for biting and cutting. Canines - pointed for puncturing and tearing. Bicuspids (premolars) - have two points for shearing and shredding. Molars flattened for grinding and crushing. Carnivores have a full set of teeth. The teeth of deer are quite different.

3.5a assignment - Mammals
Scoring criteria

1. List the main characteristics used to define the class Mammalia.
2. What is a dental formula? what is it used for? What is your dental formula? Who has more teeth primitive Eutherians or Marsupials? How many?
3. Describe the structure of a mammary gland.
4. Study this website about Lactation Biology from the University of Illinois to answer the following questions:
   1. What type of mammals have the highest percentage of fat in their milk?

5. Of the 26 orders of mammals, list 2 of the orders, with an animal example (common and scientific name), that are not native to the United States. (example: order - primates    common name - chimpanzee  scientific name - Pan troglodytes) (hint: read the egg laying mammals section, above)
6. Name the three type of reproductive strategies found in Mammals.
7. What is the difference between oviparous and viviparous mammals?
8. What animal has the distinction of being the only poisonous mammal in North America? (hint: use the mammal characteristics link at the top of the page) 
9. How long, in days, is the gestation period for humans? How does this compare with elephants?
10. From another web page cute and paste a mammalian tooth and label (by hand the) its parts into this assignment.
11. For this section students will be dissecting a rat (Rattus norvegicus). Visit the: Rat anatomy dissection guide. Read through the guide. Search the web of Using the external anatomy link, label the external parts of the rat (numbers 1-9)  Use the head, thoracic and abdominal organs link and label the thoracic and abdominal organs. You may need to search for different pictures or diagrams of a rat. Label by hand. (You may also use this power point of a real rat dissection)       (biology corner:  all rat dissection parts)    *The idea is to have an external and internal labeled diagram of the rat.

Honors biology: along with the section above complete the section below

1. Visit this site on the life of mammals. Open the Mammal maker game and read the directions carefully. Use the beginner level to practice then move to the advanced level and complete the 10 levels as fast as you can. Record the names of each mammal from the 10 advanced levels here. What was your score? Did you make the high score table?

3.5b Mammals

Does an armadillo have hair?

	Antlers and Horns

Antlers are found in most species of deer. They are made of solid bone and grow from a bony base on the skull. Antlers begin growing in the spring as skin-covered projections. The dermal covering, or "velvet," is rich in blood vessels and nerves. When the antlers reach full size, the velvet dies and is rubbed off. The antlers are used in combat by males during the breeding season, and drop off afterwards. Antlers vary from simple spikes to enormous, branched structures. In most species, only males have antlers (both sexes have antlers in caribou).

All bovids have horns, at least in males and often in females. Horns can vary from simple spikes to extremely long, curved structures - but always un-branched. Bovid horns are made up of a permanent bony core covered with a layer of keratin, which is never shed. The horn picture above shows the hollow area where the bony core would be found.

3.5b Assignment - Mammals
Scoring criteria

1. Study these two websites and write at least one paragraph describing how a rhinoceros horn is different from a cow horn.

2. Study the webpage for each of the following mammals. Describe the economic importance, both positive and negative for each animal.

   Opossum Nine-Banded Armadillo Whitetail Deer Domestic Horse

   Eastern Cottontail Rabbit Fox Squirrel Short-Tailed Shrew Striped Skunk

3. Right click on this(North American deer) and "save target as" to you desktop. After video has downloaded watch the video and complete the questions below.
   1. How many different types of deer live in the world today? How many are found in North America?
   2. How much can a moose weigh?
   3. How many stomachs does a deer have?
   4. What are browsers?
   5. How many toes does a deer have?
   6. What is velvet?
   7. Give different reasons why horns are not the same as antlers.
   8. What animal is the largest member of the deer species?
   9. How deep can a moose dive in order to get food?
   10. What type of deer live in the largest herds?
   11. Explain the difference in living habitat between the white tail deer and the black tail deer?
   12. How soon can a fawn stand up after birth?
   13. Are deer in danger of extinction?

    

4. This section on mammals will include a dissection lab for a fetal pig. Pre-lab preparation is very important in that it will aid you in successfully completing the dissection. Visit the lab and read the directions carefully.

   Next complete the virtual pig dissection linked in the directions. Only fill out the answers for the following parts: (system study guides)

   • Digestive system
   • Circulatory system
   • Respiratory system
   • Reproductive system  (how can you determine the sex of your pig?)

   Attach the completed V.P.D. (virtual pig dissection) questions to this assignment.

Honors biology: Add the following task for question 4 only. (regular biology should still do question 5)

Take a look at the power point linked in the directions of the dissection lab. View those parts that pertain to our dissection.

 

5. For reference during the dissection, search for labeled diagrams of the following:
   • External fetal pig
   • Digestive system
   • Circulatory system
   • Respiratory system
   • Reproductive system

   Cut and paste them into a format that will allow you to use them as reference on the dissection lab.

 

3.5c Mammals

What is the largest part of the mammal brain?

Bats are the only mammal that can actually fly.

The order name Chiroptera literally means hand-wing, which is an indication that the fingers are the origin the the bat's true wing.

Mammal Skulls:

Mammal skulls have the same basic bones, but one of the most accurate ways to identify a mammal is by its skull. Compare the shape of these two skulls: coyote and German Shepard. You might think the skulls of these animals would be shaped very much alike, but it is easy to see the difference in the two. Notice that the coyote skull slopes gently from the top of the head to the snout while the dog skull slopes very quickly.

Mammal brains:

Mammal brains are the most highly developed in the animal kingdom. While the shape and size differ from species to species, all mammal brains are essentially like yours.

Assignment - mammals
Scoring criteria

 

1. Find a picture of a mammal skull on the Internet. Insert the picture onto a PowerPoint slide or word document. Label the following parts on the skull:
   1. orbit (eye socket)
   2. cranium (brain case)
   3. incisors
   4. canines
   5. cheek-teeth (molars & premolars)
   6. nasal bone
   7. zygomatic arch
   8. bony crest (sagittal crest & occipital crest)
   9. lower jaw (mandible)
   10. auditory bullae

    

2. Use the links above to find a diagram of a human brain. Cut and paste the brain into this assignment and label all the brain parts.
3. Use the links above to search for and compare the following mammal brains. How are they similar and how are they different? How do they compare to the human brain?
   1. bat
   2. elephant
   3. zebra

4. Use either of these links   to identify these mammal skulls:

5. What is the heart rate of the Little Brown Bat when hibernating?

6. What is the Arizona State Mammal?

    

Research Links:

• Search - The Animal Diversity Web

• Orders of Mammals - The Tree of Life Project
• Species Identification - Audubon Field Guides Online
• Mammals of Texas - Texas Parks and Wildlife
• Mammal Species of The World - National Museum of Natural History, Smithsonian Institution
• Mammal Skulls - Will's Skull Page
• All About Bats - Bat Conservation International
• More Bat Links - The Birmingham Zoo
• Squirrels - Illinois Natural History Survey
• Beavers - Illinois Natural History Survey
• Bobcats - Illinois Natural History Survey
• All About Shrews - The Shrew Site
• Guide to the World's Hoofed Mammal Species - by Brent Huffman
• Deer Net - University of Alberta
• Legacy of the Horse - International Museum of The Horse
• Fossil Horses - Florida Museum of Natural History
• Monotremata - University of Tasmania

   

   

  

   

   

   

   

   

   

   

     

   

  Unlike most mammals which have seven, the armadillo has nine cervical vertebrae.

   

   

   

   

   

   

   

     

   

  There is a lot of hair on an armadillo's body.
  Hair covers the belly and grows between the plates of the shell.

   

   

   

   

   

   

   

     

   

  The largest part of a mammal brain is the cerebrum, containing over 50% of the animal's nerve cells.