Fossils, Geology, Primate Origins Flashcards
taphonomy
branch of paleontology that deals with fossilization
statigraphy
study of rock layers, establish relative ages
Law of Superposition
sedimentary layers are deposited in a time sequence, oldest on bottom
lithostratigraphy
use characteristics of rock layers to link sedimentary sequences and establish
tephrostratigraphy
using chemical similarities of volcanic ash layers to determine time equivalence across
biostratigraphy (faunal succession)
using organisms themselves (fossil index) to establish relative ages across sites
paleomangetism
using changes in earth’s magnetic polarity to establish age
arboreal hypothesis
primate characteristics evolved as adaptations to arboreal lifestyle
disproved: primate ancestors already arboreal
visual predation hypothesis
primate characteristics evolved as adaptations for stalking and grasping insect prey in small terminal tree branches
- reduced olfaction = secondary result of close eyes
angiosperm exploitation hypothesis
primates co-evolved with adaptive radiation of flowering plants to exploit their products (fruits, flowers, nectar) and insects that feed on them
consensus view
incorporates ideas from visual predation and angiosperm exploitation models
- consistent w/ fossil evidence showing that earliest primates were nocturnal and had adaptations for insectivory and fruit-eating
dental adaptations for humans
canine reduction
teeth arcade
prognathism
muscles of mastication
skull adaptations for humans
sagittal crest
less robusticity
bipedal roots in ape skeletons
suspensory locomotion
knuckle-walking
anatomical mods needed for bipedalism
center of gravity
foramen magnum position
body proportions
vertebral column
pelvis shape
knee
