Chp 8, Fossils Flashcards
What are Fossils?
Remains of once-living organisms
What is Taphonomy?
The study of what happens to an organisms remains
What is Sedimentary?
Rock formed when the deposition of sediment creates distinct layers of stratas
Who is William Smith?
An engineering surveyor that created the hypothesis Principle of Faunal Succession
What is the Principle of Faunal Succession?
The relative positions of strata and fossils found in the layers are the same
What are the 3 ways Fossilization can occur?
1) Organism remains are in an oxygen free environment.
2)Volcanic ash buries remains
3) Remains are transformed into sedimentary rock
What are the Key stages missing in fossil record?
1)Paleo. have only searched in minimal places
2)Fossils are preserved in some places
3) Rock sequences containing fossils are not complete in all places
What the most commonly found fossils?
Bones and teeth
Order of evolution organized by Paleo. ?
Paleozoic, Mesozoic, Cenozoic
Who is James Ussher?
Archbishop who asserts that Earth was created on Sunday, Oct 23, 4004 BC
Who is Niels Stensen aka Nicolaus Steno?
Pioneer of Steno’s Law of Superposition: Principle that the lower the stratum, the older its age
What is Biostratigraphic dating?
Chemical dating method that uses the associations of fossils in strata to determine each layers approximate age developed by William Smith
What is Fluorine dating?
One of the 1st chemical dating methods proposed by chemist James Middleton
What is an example of fluorine dating?
Paleontologist Kramberger applied fluorine dating to human remains, proves that both animals Krapina Neanderthals were in Pleistocene area
What is an example of Bio.strat dating?
Irish elk fossil predates northern Eur. site, 10,600 yBP
What is the 1st evidence for Cultural dating?
Pebble tools: 3.3 mya
Who is A.E Douglass?
Pioneer of Dendrochronology chronometric dating method that uses a tree-ring count to determine numerical age
Who is Willard Libby?
Pioneer of Radiocarbon dating, method 14C to 12C is measured to provide an absolute date for a material younger than 50,000 yrs
What is Amino acid dating?
Absolute dating method for organic remains such as bone. Based on the decay of protein molecules after date
What is Racemization?
Chemical reaction resulting in the conversion of L to D for AA dating
What is Polarized light?
A kind of light used in AA dating- allows changes to be measured and dated
Example of Amino Acid dating?
1)Dating Boarder Cave in South Africa (145,000-70,000 yBP)
2) Human occupation during the Pleistocene in Britain
What is Paleomagnetic dating ?
Absolute dating method- based on the reversals of Earth’s magnetic field
What is Electron spin resonance dating?
Absolute dating method- uses microwave spectroscopy to measure electrons spins in various materials
What is Thermoluminescence dating ?
Dating method in which the energy trapped in a material is measured when the object is heated
What is Genetic dating?
Geneticist M. Goodman, et, all developed the molecular clock for dating the divergences of the major primate taxa
Example of genetic dating?
Old world monkeys 1st diverged from all other primates at about 14 MYA
What is Temperature in the anthropological context?
Single most important feature of climate. Scientists can identify and study the effects of temps. on biologic and geologic chemistry
Example of reconstructed temperature?
Study of Foraminifera- atmospheric temp. directly affects the waters temp- affects the mount of 18O microorganism increases-vice versa
What are C3 plants?
C3 photosynthesis- Co2- 3 carbon atoms- temperate regions-includes wheat, sugar, hardwood, trees
What are C4 plants?
C4 photosynthesis- Co2- 4 carbon atoms- warmer regions, low humidity- includes corn, sugarcane
Examples of C3 & C4?
Scientists can determine which kind of plant an animal ate based on the ratio 13C to 12C in animals remains
What is the Paleozoic era?
1st major era of geologic time, 545-240 mya, fish, reptiles & insects appeared
What is the Mesozoic era?
2nd major era of geo. time, 230-66 mya, emergence & extinction of dinos
What is the Cenozoic era?
The era lasting from 66 mys-present, encompasses the radiation & proliferation of mammals
What are Epochs?
Divisions of periods in geologic time
What is the Pangae?
Hypothetical landmass in which all the contents were joined approximate 300-200 MYA
What is Tectonic?
Various structures on Earth’s surface i.e continental planes
What is Stratigraphic correlation?
Process of matching up strata from 7 sites via analysis of chemical, physical, & properties
What is Fluorine dating?
Chemical dating method that compares the accumulation of fluorine in animal & human bones
What is the Chemical dating?
Dating methods that use predictable chemical changes that occur over time
What are Index fossils?
Fossils that are from specified time ranges, found in multiple sites, & can be used to determine the age of associated strata
What is an Isotope ?
2 or more forms of a chemical element
What is an Igneous rock?
Rock formed form the crystallization of molten magma
What is Fission track dating ?
Absolute dating method based on the measure of the # of tracks left by the decay of uranium-238
