Mammal Locomotion Flashcards
What is a plantigrade limbs?
An animal that has all its phalanges and metatarsals/metacarpels on the floor (eg. us)
Not really evolved for high speed, eg. Shrews bears and rodents
What is a digitigrade limbs?
Has its phalanges on the floor but not metatarsals/metacarpals (eg. Dog)
Greater acceleration because of muscles and tendons stretched out, eg. Foxes and rabbits/hares
What is an unguligrade limbs?
Only toe nails/tips of toes are on the floor (eg. Pigs)
Terminal phalanges and hooked support weight
Little muscle at ends of limbs, most is in shoulders, toes and limbs are very light, so great speed and endurance
What are perissodactyla limbs?
Odd toes unguligrades
Eg. Rhinos (3) and horses (1)
What are Artiodactyla limbs?
Even toed unguligrades
eg. Hippo (4) deer/bovines (2)
Why did different limb forms evolve?
- Evolutionary arms race between predators and prey?
2. Need to move longer distances to obtain food after low productivity grasslands replaces high productivity woodlands
What are graviportal limbs?
Massive columnar limb bones to resist crushing under great body weight
Eg. Elephants, diplodocus
Give examples of specialised feet
Moles: huge phalanges with claws, for digging
Squirrels/sloths: gripping feet and claws
What evolutionary advantage in hands and feet do primates have for climbing trees and gripping things?
Opposable thumbs
What are volant mammals?
Mammals that can glide, do not generate lift, but sustain height over longer distances than normal
They have the Patagium, the flight membrane
What are chiroptera?
Flying mammals -> bats 986 species
They generate powered flight, patagium stretched over modified phalanges of forelimb to hindlimb and tail
What adaptions to amphibious mammal forms have?
Tail as propeller and rudder, webbed feet
Eg. Otters and beavers
Give examples of mainly aquatic mammals
Walrus, sea lions, fur seals
(Pinnipeds)
True seals, elephant seals
(Phocidae, forelimbs reduced, hind limbs permanently reflected backwards)
Give examples of completely aquatic mammals?
Cetacea
- Odontoceti (toothed): sperm, killer, dolphins, porpoises
- Mysticeti (baleen whales): blue, minke, right
What are the Sirenia?
Dugong and manatees (4 species) In same class as elephants and aardvark
