Date post: | 20-Jan-2016 |
Category: |
Documents |
Upload: | roberta-mccormick |
View: | 219 times |
Download: | 0 times |
Examples of Saltatorial Mammals
Lemuridae
Macropodidae
Saltatorial Rodents
HeteromyidaeDipodomys ingens: Giant
Kangaroo Rat
DipodidiaeEuchoreutes naso- Long
Eared Jerboa
Muridae: Gerbillinae
Muridae: Murinae
PedetidaePedetes capensis Cape
Springhare
Saltatorial Adaptations
A. All these forms have very long hind limbs: selection has optimized Vo & they have very long out levers on their hind limbs.
B. They have large hind limb musculature to compensate.
There often is a reduction in number of digits in the hind limb.
The front limb is almost always very generalized, and is used in feeding, grooming, etc.
C. Other AdaptationsStiffening of axial skeleton.
Elastic energy storage mechanisms.
Long counter-balancing tail.
D. Advantages:rapid accelerationextreme maneuverabilty.
Cursorial Adaptations: Increase Stride Length
1.Increase length of distal elements
2. Change in foot posture.
Cursorial Adaptations: Increase Stride Length
PerrisodactylsCetartiodactyls
Fused metapodials – cannon bone
Cursorial Adaptations: Increase Stride Length
3. Loss/Reduction of clavicle – allows scapula to rotate during stride.
Suspension of front limb in muscular sling
Cursorial Adaptations: Increase Stride Length
4. Increased dorso-ventral flexion of spine.
Incurs a huge energetic cost.
Cursorial Adaptations: Increase Stride RateOptimize Vo
1. Short in-levers and long out-levers.
2. Increase the number of joints: Vo Total = Sum of all Vo in limb
Vo(Total) = Vo(Scapula) + Vo(Humerus) + Vo(Ulna) + Vo(Cannon Bone) + Vo(Hoof)
3. Decrease inertia of limb distally
Loss of peripheral digits.
Confine movement to a single plane – astragalus.
Concentrate muscles to proximal portion of limb.
Scansorial Mammals
Prehensile Organs
AtelesAteles geoffroyi:
Geoffroys’s Spider Monkey
Claws
SciurusSciurus carolinensis:
American Grey Squirrel
Friction Pads
Erethizon
GalagoGalago crassicaudatus:
Greater Bushbaby
Myzopoda aurita (sucker-footed bat)
GlidingPetaurus
Eupetaurus
Cynocephalus
Stylar cartilage
Gliding
Thorington et al. Journal of Mammalogy, Vol. 79, No. 1
pp. 245-250.
Eupetaurus - wooly flying squirrel
Swimming
Lutrines (Mustelidae) Hippopotamids
Hippopotamus amphibius Lontra canadensis
Swimming
Otariids Phocids
Phoca vitulinaZalophus californicus
Transitional sirenian fossils (Pezosiren):
Domning (2001. Nature)
Transitional pinniped carnivoran fossils (Puijila):
Rybczynski et al. (2009. Nature)
Pakicetus
Ambulocetus
Some fossil cetaceans
Basilosaurus
Megaptera
Hind limb