P. Chordata - Mammalia Pt. 1 Flashcards
What are cardinal features of being a mammal?
Hair
Mammary Glands
Strong jaw/heterodont
Large brain
Large, strong girdles
What is the function of the mammary glands?
Mammary glands function in nourishment and provide direct care for the young.
Function of hair for mammals?
Hair functions as insulation.
Describe the different types of mammals based on how they birth their young:
There are…
- Monotremes
- Marisupals
- Placentals
Give an example of monotremes
Duck-billed platypus
What type of animals would fall under marsupials?
Kangaroo, possum, koala, etc.
Example of a placental:
Bears, humans, deers, etc.
What does oviparous mean and what type of mammal does it fit under?
Oviparous means to lay shelled eggs and it fits under Monotremes.
What does viviparous mean and what type of mammal does it fit under?
Viviparous means to bear live young and this is done by marsupials and Placentals.
What is the difference between viviparous marsupials and viviparous Placentals?
Marsupials birth their young around 8 weeks which would be considered premature for Placentals.
Placentals typically carry theirs to term. Their young develop to a later stage.
For the 3 types of mammals, what are the temperature conditions they prefer?
Monotremes = Tb 32
degrees celsius
Marsupials = Tb 35 degrees celsius
Placentals = T 38 degrees celsius
What are two ways a mammal can increase their running speed?
1) Narrow the foot
2) Lengthen the distal portion of the leg
(increase length of stride)
How can the foot be narrowed in order to increase speed?
1) It can be compacted and
2) the mamma can lose digits (reference slides)
Define a distigrade:
These are mammals that move using only the ball of their foot and toes, moving their ball of for first.
Ex. Dog
What is a plantigrade?
A plantigrade is a mammal that uses all three parts of their foot” the heel, ball of their foot, and their toes.
Ex. humans
What is an unguligrade?
These mammals move with their toes only.
Ex. Deers
