Mammalogy Lecture 5
Terms
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- Where did Monotremata
- Australia
- Where did Metatheria fossils appear?
- North America
- What's the earliest Metatherian fossil?
- Clemensia; placed in the Family Didelphidae
- Where were primitive Eutherians found?
- China and North America
- What are Didelphimorphia?
- Opossums
- What are Paucituberculata?
- Shrew Opossums
- What were Taeniodonta?
- Semi-fossorial insectivores
- What were Tillodonta?
- Rodent-like w/large incisors
- What were Pyrotheria?
- Herbivorous ungulates, rather elephant-like
- What were Condylartha
- Ungulates
- What were Pantodonts?
- Side branch of Condylartha
- What were Dinocerata?
- Grotesque, lg rhino-like beast
- What were Creodonta?
- Carnivorous, possibly ancestor to Recent Order Carnivora
- What are Xenarthra?
- Primitive armadillo-like mammals
- What were Dermoptera?
- Culugo (flying mammal)
- What type of eggs do Monotremata have?
- Macrolecithal and Telolecitha egg
- What is a Telolecithal egg?
- yolk concentrated towards vegetal pole of ovum (same as in birds, other mammals have isolecithal eggs)
- What is a Macrolecithal egg?
- lg amounts of yolk (all other mammals have a microlecithal egg)
- What is an isolecithal egg?
- Evenly distributed yolk (other mammals)
- Monotremata eggs have what kind of cleavage?
- Meroblastic: early cleavage (cell division) restricted to sm disc at the animal pole (same as birds)
- Which ovary(ies) are functional in a platypus? Echidnas?
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Platypus: left ovary functions
Echidnas: both - What's present in the oviduct of a monotremata?
- Shell gland
- Describe 3 characteristics of the male monotremata's anatomy of reproductive system
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1.Testes are abdominal
2. Seminal vesicles and prostate glands are absent
3. Penis bifurcated; baculum absent - Describe the pouch in echidnas and platypus
- Echidnas develop a temporary pouch while platypus never develop a pouch
- How long do monotremata incubate their eggs for? WHat's special about their mammaries?
- 7-10 days. Mammary glands lack nipples and young suck milk from lobules (tuffs of hair) in pouch of ehidna
- List the fossil record of the monotremata
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1. Primitive monotreme (steropodoon)-Early Cretaceous fm New South Wales of Australia
2. Platypus (3 teeth)-Early Paleocene fm Patagonia
3. Platypus (teeth & pelvis)-Middle Miocene fm Australia
4. Recent genera known fm the Pleistocene of Australia - What are the living families of Order Monotremata
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1. Family Tachyglossidae
2. Family Ornithorhynchidae - What animals are in the Tachyglossidae Family?
- Echida or spiny anteaters
- How many living Genera of the Tachyglossidae Family are there?
- 2 (short and long nosed Echidna; common names)
- What does Myrmecophagus mean?
- Ant loving or ant feeder
- Briefly describe their foraging habits
- Turn over stones and dig open ant and termite nests to feed off of ants, termites, and other invertebrates
- Describe the Tachyglossidae's mouth
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1. Loss or great reduction of teeth
2. Dentary greatly reduced, slender and delicate
3. Long, protrusile tongue
4. Viscous mucus - How many eggs are layed and incubated in the pouch by the Tachyglossidae
- Single leathery-shelled egg
- Describe the Tachyglossidae's hibernation
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1. True hibernation: body temp drops to 5.5C when ambient temp in 5.0C
2. Hibernation initiated by cold and lack of food
3. Arousalfm hibernation is spontaneous - What is the only species in the Family Ornithorhynchidae?
- Duck billed platypus
- What do Duck billed platypus feed on and where?
- Larval insects; primarily bottom feeders and remain submerged for up to a minute
- Where are Duck-billed playtpus found (geographically)?
- Eastern Australia and Tasmania
- What's the population status of the platypuss?
- Thought to be endangered: common but vulnerable to local extinctions
- Describe the reproduction of the Duck-billed platypuss
- 1 to 3 eggs, usually 2, laid in a nest of moist leaves b/w late August and mid-October: Burrow 50ft or more in length