Bats, Primates Flashcards
What are the key characteristics of monotremes?
• Late Jurassic/early Triassic origin
• Duckbilled platypus, echidna
• Single cloacal opening
• Lay eggs
• Lack nipples, secrete milk from skin
• 5 species, restricted to Australia & New Guinea
Monotremes are unique among mammals due to their egg-laying and milk secretion methods.
What features are shared between marsupials and eutherian mammals?
- Higher metabolic rate
- Nipples providing milk
- Live young
Marsupials exhibit several traits that align them closer to eutherians, facilitating their survival and development.
How are marsupials distributed globally?
• 200 species in Australasia
• 130 species in South & North America
• Earliest fossils from South America
• Australian marsupials have diverse ecological roles similar to eutherians
• North & South American marsupials consist of 3 families
The distribution reflects historical continental drift and ecological adaptation.
What significant event occurred during the Cretaceous period concerning marsupials and placentals?
Marsupials and placentals split in the Cretaceous period
This split led to the development of distinct evolutionary paths for these two groups of mammals.
What are some examples of eutherian mammals?
• Human
• Blue whale
• Proboscidea
• Xenarthra (sloths, anteaters, armadillos)
• Rodentia
• Lagomorphs (hares and rabbits)
• Primates (lemurs, monkeys, apes)
• Carnivora (cats, dogs)
• Chiroptera (bats)
Eutherians are characterized by their complex reproductive strategies involving a placenta.
What are the general characteristics of mammals?
• Endothermic
• Hair
• Mammary glands & sweat glands
• Placenta (most)
• Large cerebral neocortex
• Extended parental care
• Specialized teeth
• Jaw structure
• Auditory ossicles
These traits define mammals and distinguish them from other animal classes.
How many species are in the Chiroptera order?
1100 species
Chiroptera includes bats, representing about 20% of all mammal species.
What are the two suborders of Chiroptera based on current molecular studies?
• Yinpterochiroptera
• Yangochiroptera
These classifications reflect evolutionary relationships among bat species.
What is echolocation?
Echoes of emitted sound waves that gather a picture of the environment
Echolocation is crucial for navigation and hunting in certain mammals, particularly bats and some marine animals.
Which families primarily exhibit hibernation as a form of heterothermy?
• Vespertilionidae
• Rhinolophidae
Hibernation helps these species manage energy use during periods of low food availability.
What are the two responses of mammals to temperature extremes?
• Wing fanning & sweating to cool down
• Increased energy expenditure for heat production or heterothermic response to lower temperature
These responses are essential for maintaining homeostasis in varying environmental conditions.
What are the three groupings of primates?
- Lemurs, lorises, pottos – prosimians
- Tarsiers – prosimians
- Monkeys, gibbons, apes – anthropoids
Each grouping represents distinct evolutionary paths and adaptations.
What are some social adaptations advantages in primates?
• Individual recognition
• Enhanced cooperation in defense, parental care, feeding
These adaptations are vital for survival and reproductive success in social species.
The oldest fossil of monkeys dates back how many million years?
45 million years
This fossil evidence provides insight into the evolutionary history of primates.
Marsupial characteristics?
- Cretaceous
- Kangaroo, opossum
- Cloaca (as with monotremes)
- Yolk-type placenta – short gestation
- Marsupium for protection of young
