Term
| Subclass Protheria Orders |
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Definition
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Term
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Definition
Infraclass Metharia (marsupials)
Order Didelphimorphia opossums
Order Paucituberculata - rat opossums
Order Microbiotheria - Monito del Monte
Order Dasyuromorphia - umbat, Tasmanian devil, marsupial mice
Order Peramelemorphia – bandicoots, bilbies (7, 21)
Order Notoryctemorphia - marsupial "mole“ (1, 2)
Order Diprotodontia - koala, wombat, kangaroos, possums (38, 141 |
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Term
| Monotreme Characteristics |
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Definition
Priminitive:
-Egg laying
-Therapsid shoulder girdle
- Cervical ribs
- Epipubic bones
- No auditory bulla and uncoiled cochlea (only mammals to have this)
- no corpus callosum
- Ovaries larger than other mammals
- Oviducts open into common urogenital sinus, similar to reptile cloaca
- Milk secreted by glands in skin, licked from tufts of fur
- Abdominal testes, penis is sac in floor of cloaca
- Sperm are filiform(thread-like) and reptilian in structure
- Young have 'egg tooth'
- platypus - 1-2 eggs
- echidna 1 egg
Derived characters:
- Rhinarium
- Highly modified limbs
- Edentate as adults
- Spurs |
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Term
| Typical Platypus reproduction |
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Definition
Eggs fertilized in fallopian tubes. Uterine wall produces nutritious secretions.
Egg retained in uterus about 28 days
Leather shell added, egg laid, 10 more days of external incubation. Lactation abnout 3-4 months. |
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Term
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Definition
Similar to platypus except only 1 egg, incubated in a pouch where hatchin g
occurs. |
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Term
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Definition
| In hind leg carries venom |
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Term
| Platypus aquatic characteristics |
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Definition
Excellent swimmer and spends much time in water foraging.
Propels itself when swimming using its webbed feet and moving the front two feet in a rowing motion. |
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Term
| Platypus feeding characteristics |
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Definition
| Platypus is a carnivore that feeds on worms, insect larvae, shrimp, and crayfish. Eats about 20% of its body weight a day. |
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Term
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Definition
| Generally active in day time. Tend to be solitary and use burrow when rearing young. Feed on insects and termites. |
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Term
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Definition
| Has snouts which have functions of both mouth and nose. Their snouts are elongated and slender. |
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Term
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Definition
| Locate food by smell, using sensors in the tip of their snout. They are powerful diggers and use their clawed front paws to dig out prey.. Feed on termintes primarily in forested areas. |
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Term
| Marsupial diagnostic feature |
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Definition
| Reproductive mode: Invest very little in young before birth. Marsupial litters weigh less than 1% f the maternal mass at birth compared to up to 50% in some rodents. |
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Term
| Marsupial investment in lactation |
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Definition
| Marsupials invest more during lactation and so in the end they are somewhat comparable in total investment. |
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Term
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Definition
-Eggs slightly larger than placentals
-Bifid penis
-Uteri seperate, but females have paired vaginae
-Gestation always short |
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Term
| Dentition in marsupials: polyprotodont |
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Definition
| Long mandible with small unspecialized lower incisors |
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Term
| Dentition in marsupials: Diprotodont |
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Definition
| Shortened manible with the first pair of lower incisors englarged to meet upper incisors |
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Term
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Definition
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Term
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Definition
| 2nd and 3rd toes are fused and in a common skin sheath |
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