bones3 Flashcards
Bones to know:
Skull
Forelimb
Hindlimb
Skull
Cranium
Mandible
5 major modes of primate locomotion
Arboreal quadrupedalism
Terrestrial quadrupedalism
Vertical clinging and leaping
Suspensory
Knuckle-walking
Hindlimb:
Innominate (or pelvis)
Femur
Tibia
Fibula
Forelimb:
Scapula
Humerus
Radius
Ulna
Arboreal quadrupedalism
good for small-bodied primates moving through a relatively continuous horizontal network of branches
Terrestrial quadrupedalism
walking on the ground
Vertical clinging and leaping
smallish primates moving between discontinuous vertical supports, with no horizontal supports
Suspensory
medium to large primates that need to spread their weight across multiple smaller supports
Intermembral index
ratio of forelimb length to hindlimb length
High values = longer forelimb, shorter hindlimb (suspensory, knuckle-walkers)
~ 100 = forelimb and hindlimb of similar length (quadrupeds)
Low values = shorter forelimb, longer hindlimb (vertical clingers and leapers
Knuckle-walking
Chimpanzees and gorillas only; retain suspensory adaptations (i.e., long hands and curved phalanges) but use knuckle-walking when walking on the ground
Bony correlates of locomotion
Intermembral index ratio of forelimb length to hindlimb length
Phalangeal curvature and length
Tail length
Phalangeal curvature and length
Long curved phalanges more arboreal
Short straight phalanges more terrestrial
Tail length
Long tail more arboreal
Short tail more terrestrial
Incisors
used for nipping, scraping, ingesting
Tooth types and their functions:
Incisors
Canines
Premolars
Molars
Canines
fighting, stabbing, biting, holding prey, display
Premolars
anteriorly canine-like, posteriorly molar-like
Molars
for chewing – shearing, slicing, crushing, grinding food into smaller pieces to be swallowed
Diet indicators in tooth morphology
Molar crests and cusps
Incisor size and shape
Molar crests and cusps:
High cusps and sharp crests flexible but tough foods (e.g., fibrous foods like leaves)
Blunt, low cusps less fibrous foods that can be soft (e.g., pulping fruit) or hard and brittle (e.g., crushing nuts)
Incisor size and shape:
Broad incisors taking bites out of fruits
Small inciors stuffing leaves into mouth, no bites necessary
Dental formula
Count the number of incisors, canines, premolars, and molars in ONE HALF of ONE JAW
