ANT 2511 Exam 3 Sinelli Flashcards
What is a fossil?
the remains of an organism chemically changed into rock
What is taphonomy?
the study of what happens to an organism after death
Best conditions for fossilization?
soil, sediments, water, sand, mud, ash
Steno’s Law of Superposition in Stratigraphy
things on the bottom are older than
things on the top
Cultural dating
things found together can be related and used to date each other
Relative dating
simple observation that one artifact or fossil is older than another. Ex: stratigraphy, biostratigraphy, cultural dating, flourine dating
Absolute dating
methods provide specific dates and time ranges. Ex: K-Argon dating, fission track dating, luminescence dating, dendrochronology
Dendrochronology
based on reading rings of trees
Radiocarbon C14 dating
-based on the
decay of 14C, which is an unstable isotope of carbon.
-Carbon 14 has a half-life of 5,730
years
-Only used on remains of biological organisms
-date up to 50,000 years old
Argon dating
-half-life of circa 1.3 billion years
-based on decay of potassium-40 (40K) to argon-40 (40Ar)
-dates the layers around the fossil to give approximate dates for when fossil was deposited
Hominin
Members of the Family Hominidae that occurred after the split from African great apes
Protohomin
-Early hominin, do not exhibit all the characteristics of hominins. maintain some climbing/ robust features.
-Sahelanthropus tchadensis, Orrorin tuganensis
How is bipedalism in hominids distinct from that of birds and kangaroos?
-“habitual” bipedalism in humans, main form of locomotion
-bipedal posture, body always at 90 degree to walking surface
Skeletal indicators of bipedalism
-foramen magnum position—centered (anterior) toward the back (posterior)
-S-shaped spine
-basin shaped pelvis, (also know impacts on birthing with bipedal pelvis shape)
-lower limb features: enlarged femoral head, knee angled inward, short toes
-arched feet
-Valgus angle (Knees inward)
Foramen Magnum position
Means “Large Hole”
Ape: Spine attaches to back of skull
Hominin: Attaches under skull, indicating bipedalism