Flashcards in Mammal overview Deck (49)
Give the 2 subclasses of the mammal class.
Give the 2 infraclasses of the subclass Theria.
What is the difference between organisms in the subclass Prototheria and Theria
Prototheria- Lay eggs
Theria- Have live young
What has caused drastic changes in the mammalian phylogeny ?
How many mammalian orders are there ?
How many species exist in the mammalian order ?
Give a broad description of a mammal.
Group of animals with;
Bodies with fur (?)
Nurse infants with milk
Unique jaw articulation
What is the mammae ?
Mammary gland, where milk production takes place
What is a mammillae ?
A nipple/teat, delivers milk to the infant
How many mammaries will an organism have ?
Generally twice as many mammaries as the average litter size.
What are the benefits of feeding via the mammary system ?
Guarantees constant supply of food
Female can redistribute energy into milk production
Little energy required for offspring to feed.
What one species has paternal lactation ?
Dayak fruit bat
What bone has articulated to form the mammalian jaw ?
Has met with the squamosal bone in the skull to form jaw.
Which ancestral bones are responsible for an increase in the acuteness of mammalian in hearing ?
The quadrate and Articular bone.
The quadrate bone has become the....
Incus of the inner ear
(decreased in size)
The articular bone has become the....
Malleus of the inner ear
(decreased in size)
How many jaw joints do mammals have in the present day ?
One jaw joint, giving more efficient chewing.
How do mammalian teeth differ from shark teeth ?
They do not continuously grow.
Will replace them once or never.
Give cycle of placental mammal teeth.
Which teeth remain constant throughout a placental mammals life ?
Molars, only one set.
Give the cycle of marsupial teeth.
Only last premolar will be replaced
What enamel is found on mammalian teeth ?
What is an occipital condyle ?
Where the skull meets the top of the neck vertebrate.
How many occipital condyles do mammals have ?
What is the advantage to mammals of having 2 occipital condyles ?
Decreases tension on skull
Allows greater control of head movement
How many occipital condyle do birds have ?
What is the disadvantage of 2 occipital condyles ?
Decreased lateral head movement
Give the earliest fossil evidence of mammals.
160 million years ago
Who do mammals share there AMNIOTE common ancestor with ?
Reptiles, Dinosaurs, Birds,