Ch 8: Fossils

Paleontology

The study of extinct organisms, based on their fossilized remains

Ch 8: Fossils

Fossils

The preserved remnants of once-living things, often buried in the ground

Ch 8: Fossils

Geology

The study of Earth systems

Ch 8: Fossils

Taphonomy

The study of what happens to the remains of an animal from the time of death to the time of discovery

Ch 8: Fossils

Strata

Layers of rock

Ch 8: Fossils

Stratigraphy

The study of the order of rock layers and the sequence of events they reflect

Ch 8: Fossils

Uniformitarianism

• Originally developed by Hutton
• processes operating today are also those that operated in the past

Ch 8: Fossils

The Principle of Original Horizontality

• Nicholas Steno
• Layers of rock are laid down parallel to the earth's gravitational field and thus horizontal to the earth's surface

Ch 8: Fossils

The Principle of Superposition

• Steno
• With all other factors equal, older layers are laid down first and then covered by younger layers

Ch 8: Fossils

The Principle of Cross-Cutting Relationships

• Hutton
• A geological feature must exist before another feature can cut across or through it, and that the thing that is cut is older than the thing cutting through it

Ch 8: Fossils

The Principle of Faunal Succession

• William "Strata" Smith
• Deeper fauna is older
• There are predictable sequences of fauna through strata
• Once a fossil leaves a section (goes extinct), it doesn't reappear in a higher section

Ch 8: Fossils

Geologic Time Scale (GTS)

The categories of time into which Earth's history is usually divided by geologists and paleontologists: eras, periods, epochs.

Ch 8: Fossils

Our Present GTS date

• Phanerozoic Eon
• Cenozoic Era
• Quaternary Period
• Holocene Epoch

Ch 8: Fossils

Provenience

The origin or original source (of a fossil)

Ch 8: Fossils

Relative Dating Techniques

Dating techniques that establish the age of a fossil only in comparison to other materials found about and below it

Ch 8: Fossils

Lithostratigraphy

• A relative dating method
• The study of geologic deposits and their formation, stratigraphic relationships, and relative time relationships based on their lithologic (rock) properties

Ch 8: Fossils

Tephrostratigraphy

• A relative dating technique
• A form of lithostratigraphy in which the chemical fingerprint of a volcanic ash is used to correlate across regions

Ch 8: Fossils

Biostratigraphy

• A relative dating technique
• using comparison of fossils from different stratigraphic sequences to estimate which layers are older and which are younger

Ch 8: Fossils

Calibrated Relative Dating Techniques

Techniques that use regular or somewhat regular processes that can be correlated to an absolute chronology to estimate the age of a site.

Ch 8: Fossils

Geomagnetic Polarity Time Scale (GPTS)

Time scale composed of the sequence of paleomagnetic orientations of strata through time

Ch 8: Fossils

Paleomagnetism

The magnetic polarity recorded in ancient sediments. Reversed or normal direction is used to correlate with the geomagnetic polarity time scale (GPTS) to infer an age for a site

Ch 8: Fossils

Chronometric Dating Techniques

Techniques that estimate the age of an object in absolute terms through the use of a natural clock such as radioactive decay or tree ring growth

Ch 8: Fossils

Radiometric Dating

Chronometric techniques that use radioactive decay of isotopes to estimate age

Ch 8: Fossils

Isotopes

Variant forms of an element that differ based on their atomic weights and numbers of neutrons in the nucleus. Both stable and unstable (radioactive) isotopes exist in nature.

Ch 8: Fossils

Half-life

The time it takes for half of the original amount of an unstable isotope of an element to decay into more stable forms

Ch 8: Fossils

Parent Isotope

The original radioactive sample

Ch 8: Fossils

Daughter Isotope (product)

The isotope that is produced as the result of radioactive decay of the parent isotope

Ch 8: Fossils

Potassium-Argon (K-Ar) dating

Radiometric technique using the decay of [potassium40] to [argon40] in potassium-bearing rocks. Estimates the age of sediments in which fossils are found

Ch 8: Fossils

argon/argon (argon40/argon39) dating

Radiometric technique modified from K-Ar that measures potassium40 by proxy using argon39. Allows measurement of smaller samples with less error

Ch 8: Fossils

Fission Track Dating

Radiometric technique for dating noncrystalline materials using the decay of Uranium238 and counting the tracks that are produced by this fission. Estimates the age of sediments in which fossils are found.

Ch 8: Fossils

Uranium Series (U-series) techniques

Radiometric techniques using the decay of uranium to estimate an age for calcium carbonates including flowstones, shells, and teeth

Ch 8: Fossils

Radiocarbon Dating

Radiometric technique that uses the decay of carbon14 in organic remains such as wood and bone to estimate the time since death of the organism

Ch 8: Fossils

Electron Trap Techniques

Radiometric techniques that measure the accumulation of electrons in traps in the crystal lattice of a specimen

Ch 8: Fossils

Thermoluminescence

Electron trap technique that uses heat to measure the amount of radioactivity accumulated by a specimen such as a stone tool since its last heating

Ch 8: Fossils

Grande Coupure (Big Cut)

A cold snap in the earth's temperature during the Cenozoic era which resulted in the large-scale extinction and replacement of many species

Ch 9:Origin of Primates

K-T Boundary

• A time period where drastic environmental/faunal changes occurred
• probably arising from an asteroid crashing into the earth
• contributed to the extinction of the dinosaurs
• allowed for small insect-eating mammals to grow

Ch 9: Origins of Primates

Plesiadapiforms

• Mammalian order or suborder or mammals that may be ancestral to later Primates
• late Cretaceous/early Paleocene to late Eocene
• characterized by small brains, prognathic faces
• not like primates bc lacked postorbital bar and opposable big toe, had large lower incisors and claws (not nails), small eye sockets on either side (not in front)

Ch 9: Origin of Primates

Prognathic Face

Projection of the face well in front of the braincase

Ch 9: Origin of Primates

Postorbital Bar

A bony ring encircling the lateral side of the eye but not forming a complete cup around the eye globe

• Order: Primates
• Suborder: Haplorrhini
• Infraorder: Catarrhini
• Superfamily: Hominoidea
• Family: Hominidae
• Sub-Family: Homininae
• Genus: Homo

Ch 9: Origin of Primates

Adapoids

• Family of mostly Eocene primates, probably ancestral to all strepsirhines
• small
• slow moving
• arboreal quadupeds
• ate fruit and leaves

Ch 9: Origin of Primates

• family of mostly Eocene primates probably ancestral to all haplorhines
• ate insects and fruits
• larger orbits=nocturnal
• quadrupedalism/leaping

Ch 9: Origin of Primates

Hole that monkeys have in their ears. We have a tube