The 3 subclasses of mammals differ strikingly __________________

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Prototheria (monotremes)
Metatheria (marsupials)
The 3 subclasses of mammals differ strikingly
__________________ __________________
Eutheria (placentals)
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• Monotremes Unique Reproduction
• _______
• __________
• ____________

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Unique Features of Monotreme Reproduction

• 1. ______________ (relative to body size) than
  other mammals
• 2. _______________________
• ________ opening called a cloaca, similar to
  reptile cloaca (meaning of name __________)
• 3. __________________ in skin, licked from tufts
  of fur at concentrations of glands

• 4. Young have __________ like birds to help break
  out of egg
• _____________ 1-2 eggs
• ____________ 1 egg

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How can a mammal lay an egg????

• Monotreme egg?

• Reptile egg?

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More evidence of evolution
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Typical platypus reproduction
Egg is fertilized in fallopian tubes before entry
to uterus, eventually __________________________
before being laid. __________________________ 4
mm, when laid 12 mm.
Egg retained in uterus about 28 days while
development proceeds. THEN shell added, egg
laid, _____________________________________.
__________ _______________________________________
_________ Lactation about 3-4 months.
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• Platypus
• Low body temperature around 90 degrees farenheit
• Living species of platypus lack teeth
• Only found in Australia
• Baby platypuss is called a puggle
• Small approximately 20 inches and 3 pounds
• Eat insects and crustaceans using their sensitive
  bill to
• Locate their prey.
• 7. Use front feet to swim, steer with tail and
  backfeet

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________________________
________________, incubates in a pouch where
hatching occurs. _______________________________ _
________________________ _________________________
___ more. http//animal.discovery.com/videos/foole
d-by-nature-spiny-anteater.html
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Marsupials
kangaroo
Wombat
Wallaby
Koala
Marsupial wolf
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Our friend, the opossum only marsupial in north
america

1. __________________ (0.16 g)
2. Attach to nipples in pouch ____________
3. Short gestation, longer lactation

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Opossum
Mating season, January July, 1-2 litters
depending on latitude.
Egg fertilized in fallopian tubes,
_____________________________ ____________________
__________ ___________________________. Last 1/3
of gestation (4 days), membrane shed, eggs sink
into depressions in uterine wall
(___________________, but no firm implantation),
absorbs nutrients and embryos continue to grow.
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________________________. 7-9 young make it to
suckling stage.
Lactation continues to a total of about 95-105
days. Rarely live longer ___________________. In
wild, maximum known lifespan was 3 years.
Females often get just ________________________.
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Some differences (from placentals) found in
marsupials

• _______________________
• _______________________
• _______________________
• _______________________
• ________________
• Gestation always short as or shorter than length
  of estrus cycle

• _________________
• Many have pouch, but some only have folds of
  skin, and a few dont have anything

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Differences in female reproductive tractsLabel
The Diagram
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_________________ _________________ ______________
____
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Gestation versus lactation
What does this graph show? _______________________
__________________________________________________
__________________________________________________
_________________ What does this data
mean? ____________________________________________
________________________________________
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Another way to look at this...
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Time conception to weaning
Takes marsupial longer than placental to raise
young to same size (weaning age)
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So, which is better?
_________Lactation is most energetically costly
period of reproduction, and less efficient means
of energy transfer to young. Probably costs them
a bit more in terms of time and
energy. ____________ Newborn marsupials need to
be able to crawl to pouch or teat, suckle,
breathe, digest. But no wings, hooves, or
flippers! ___________Marsupials in individual
offspring at time of birth, can adjust litter
sizes, etc.
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Placental vs. marsupial morphology
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Australian Marsupials Over 140 species Most
are threatened due to
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Red Kangaroo
Diet Herbivore Average life span in the wildUp
to 23 years Size 3.25 to 5.25 ft Weight200 lbs
Group nameMob Can reach speeds up to 35 mph and
jump over 6 feet
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Diet Lives on eucalyptus leaves Average life
span in the wild20 years Size23.5 to 33.5 in
Weight20 lbs Protection status Threatened.
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Bandicoot/Billby Over 40 species Diet
omnivore Lifespan 2-3 years Size 7-14 inches
1-3 pounds All species are endangered
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Tasmian Devil Diet Carnivore Lifespan 5
years Size20 to 31 in Weight9 to 26 lbs
Protection statusEndangered
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The Amazing Antechinus!
All females give birth within a few days each
year. In late Sept, shortly after females mate,
all males die! ____________ only 1 reproductive
period per lifetime _____________ multiple
reproductive events per lifetime