GEO 103 - Lesson 4
Modifications for living in a certain way and performing particular functions
Adaptations
Another division of the marine ecosystem (aside from pelagic), the "bottom"
Benthic realm
When burrowers churn and mix sediment, resulting in destruction of original grain orientations in clastic sediments
Bioturbation
A body of rock that is identified strictly on the basis of its contained fossils
Biozone
Occurs when soft tissues are preserved as thin films of carbon
Carbonization
In drilling for oil, geologists recover Devonian conodonts in a stratum known to be Permian in age. Explain how this may have occured
Conodonts are made of the durable mineral apatite. The conodont in question was eroded from a Devonian layer (along with quartz sand grains), was transported by wind and water, and was then deposited into a layer of sediment during the Permian. This is known as a reworked fossil
Mollusks, crustaceans, and fish are considered...
Consumer organisms (carnivores)
Species not restricted to any single geographic location within a terrestrial environment
Cosmopolitan species
A chronostratigraphic (time-rock) unit contains a different fossil assemblage at one locality than another located 200 km away. Suggest a possible cause for the dissimilarity.
Ecological differences
Species confined to a particular geographic location
Endemic species
Benthic animals that live on top of the sediment that carpets the sea floor
Epifaunal
The remains or traces of ancient life
Fossils
The interval between the first and last appearance of a species
Geological range
The places where an organism lives
Habitat
The study of trace fossils
Ichnology
Fossils that are abundant, widely dispersed, and derived from organisms that lived during a relatively short span of geological time
Index/guide fossils
Benthic animals that burrow in the soft sediment for food and protection
Infaunal
Area between high and low tide, creatures must be able to tolerate wet and dry conditions here
Littoral zone
True swimming animals; in the pelagic realm
Nekton
The particular role played by the animal or plant as it interacts with all the physical, chemical, and biologic elements of its immediate environment
Niche
Using fossils for age correlation is dependent on a priori knowledge of their age ranges. How has this knowledge been obtained?
Observing fossil occurrences in rock layers from the past 200 years
The study of the interaction of ancient organisms with their environments
Paleoecology
Biological components of marine ecosystems are classified according to their so-called trophic, or feeding, level. Which of the following is a producer organism as contrasted with a consumer organism?
green plant
The technical term for the intertidal zone is
littoral
Which of the following is a trace fossil?
mammoth footprint
A marine organism that lives in the water column, between a depth of 0 to 1000 meters, and is an active swimmer is best classified as a(n)
pelagic, nektonic organism
The addition of a chemically precipitated substance into pore spaces
permineralization
Imagine finding a large brachiopod comprised of fool's gold (pyrite). Since brachiopods make their shells out of calcite, it is obvious that this shell has undergone some kind of change during the fossilization process. The specific alteration process displayed by this brachiopod is
replacement
Fossil A occurs in rocks of Cambrian and Ordovician age. Fossil B occurs in rocks that range in age from early Ordovician through Permian. Fossil C is Found in Mississippian through Permian strata. What is the max possible range for a stratum containing both Fossils A and B?
Ordovician
The science that seeks to understand all aspects of the succession of plants and animals over that great expanse of geological time
Paleontology
Small animals and plants that float, drift, or feebly swim in a marine ecosystem
Plankton
Green plants are considered...
Producer organisms (herbivores)
The rock body representing the total geologic life span of a distinct group of organisms
Range zone
A measure of how much biological change has occurred over a given interval of geological time
Rate of evolution
A simultaneous exchange of the original substance of a dead plant or animal with mineral matter of a different composition; dissolved the original material and replaces it with an equal volume of the new substance
Replacement
What factors determine whether or not a particular fossil will be valuable as an indicator of the age and correlation of a stratum?
Short geological range and widespread geological distribution
Fossil A occurs in rocks of Cambrian and Ordovician age. Fossil B occurs in rocks that range in age from early Ordovician through Permian. Fossil C is Found in Mississippian through Permian strata. What is the max possible range for a stratum containing only Fossil B?
Silurian and Devonian
Benthic animals and plants are most abundant here, extends from low tide levels down to the edge of the continental shelf
Sublittoral zone
The zone above high tide, harsh area
Supralittoral zone
A group of organisms that constitute a particular taxonomic category, such as species, genus, and family
Taxon
left-over tracks, trails, burrows, and borings
Trace fossils
Biologic components of the ocean ecosystem
Trophic levels
The study of processes affecting a fossil organism from the time of its death until final burial is called
biostratinomy
On a continuum from minor disruption to severe damage, which of the following biostratinomic processes does the least violence to a potential fossil?
reorientation