Introduction to Paleontology and Fossil Analysis

Paleontology

The study of extinct organisms based on their fossilized remains

Fossil

The preserved remains of once-living organisms

Taphonomy

The study of the process of fossilization

Fossilization

A rare event that requires several conditions to be met before remains can be preserved

Conditions for Fossilization

Remains must be suitable for fossilization, buried, and the material in which they are buried must be suitable for fossilization

Cranial size and shape

Indicates cognition and behavior

Hands

Indicate manual dexterity

Lower limb

Indicates locomotion

Teeth

Indicate diet, behavior, and social structure

Body proportions

Indicate ecology

Pelvis, spine

Indicate obstetrics and locomotion

Feet

Indicate bipedalism

Footprints

Provide information about locomotion, as seen in Laetoli, Tanzania

Coprolites

Fossilized feces that help understand diet and environment

The Matrix

Skeletons become fossils by absorbing minerals from their surroundings

Context

Critical for analyzing fossils and dating them

Relative dating

Dating method using principles of stratigraphy

Absolute dating

Dating method using radiometric methods and paleomagnetism

Stratigraphy

The study of rock layers and layering

Stratigraphic Laws

Principles that govern the order and age of sedimentary layers

Original Horizontality

Layers were originally flat; tectonic shifts cause them to shift

Lateral Continuity

Sedimentary regions are deposited in sheets

Superposition

The lower levels are older, and the upper layers are younger

Cross-Cutting Relations

The youngest layer is the one that cross cuts through the normally youngest layer

Law of Faunal Succession

Allows dating of sediment based on the estimated age of a fossil

Atomic Structure

Composed of protons, electrons, and neutrons

14C Dating

Estimates age based on proportion of remaining 14C, usable for remains younger than 50,000 years

Potassium-Argon dating

Based on the decay of 40K to 40Ar, useful for volcanic rocks up to billions of years old

Magneto stratigraphy

Links unknown sections to known timescales using magnetic polarity patterns