Anatomical Traits Of Non Human Primates Flashcards
Vertical clinger and leaper
Common in strepsirhines. Hind legs are longer than the front ones. This means they can sit against the tree trunk and launch themselves through the air from a vertical posture.
Example is a Indri
Generalised primate body plan 1
They lack specialisations but have versatility in modes of transport, arm swinging, running, leaping or walking. All non human primates are quadrupeds, and theres great variation in how they use their limbs.
Terrestrial quadrupeds
They walk and run on the ground and in the trees. Their arms and legs move in a limited plane of motion. The palms of the hands and feet make contact with the surface they’re walking on. Example is a Baboon
Arboreal quadruped
lives in both the trees and on the ground. The running motion features a limited range of motion of the limbs these are adapted for fast forward running, not three dimensional climbing. The scapula is orientated vertically across the upper arm and shoulder allowing the arm to swing back and forth in a pendulum motion, but not rotate.
Brachiator
An apes arm has full range of motion. This is an adaptation to arm hanging for feeding. Arm hangers need a scapula that is orientated across the back rather than on the sides to allow this freedom of motion. Apes also possess a cone shaped ribcage and torso, a long curved digit bones, small thumbs and long arms.
Grasping hands with opposable thumbs or toes
Fundamental primate adaptation, as it allows grasping with more precision.
Flattened nails
Flat nails instead of claws, this is true of all but one group of primates, marmosets and tamarins. Many strepsirhines have nails and a single claw.
Forward facing eyes
Eyes mounted on the front of the head, as a result the peripheral vision is limited by the anatomy. Forward facing eyes provide very good depth- perception because the over lapping of eyes provide a three dimensional view of the world.
Generalised teeth and diet
Shape of teeth are important and tell us about mating systems as well as diet. Most non-human primates eat a diet of a combination of leaves, fruit and other plant products with occasional animal protein in the form og insects, small mammals or other animals. Only Tarsiers eats mainly small animals.
Generalised teeth and layout
Non-human primates do not possess enormous for tearing meat or food, nor do they have molars for grinding as grazing animals do. The make up for teeth, from the middle of the dental arcade is; 2 incisors, 1 canine, 2 premolars and 3 molars. The exception being most new world monkeys that have a 3rd premolar and the strepsirhines that vary.
Petrosal bulla
Tiny bit of skeleton that covers and protects the inner ear. This is the only bony trait shared by all primates, live or extinct and it occurs in no other mammalian groups.
Enclosed bony eye orbits
Enclosed or partially enclosed eye orbits in the skull may protect the eye more efficiently than the open orbits of lower mammals. The orbit is more complete in haplorhines than strepsirhines.
