Information about Index Fossils
Index fossils (also known as guide fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages). They work on the premise that, although different sediments may look different depending on the conditions under which they were laid down, they may include the remains of the same species of fossil. If the species concerned were short-lived (in geological terms, lasting a few hundred thousand years), then it is certain that the sediments in question were deposited within that narrow time period. The shorter the lifespan of a species, the more precisely different sediments can be correlated, and so rapidly evolving types of fossils are particularly valuable. The best index fossils are common, easy-to-identify at species level, and have a broad distribution—otherwise the likelihood of finding and recognizing one in the two sediments is low.
Ammonites fit these demands well, and are the best-known fossils that have been widely used for this. Other important groups that provide index fossils are the corals, graptolites, brachiopods, trilobites, and echinoids (sea urchins). Conodonts may be identified by experts using light microscopy such that they can be used to index a given sample with good resolution. Fossilized teeth of mammals, have also been used.
Geologists use both large fossils (called macrofossils) and microscopic fossils (called microfossils) for this process, known as biostratigraphy. Macrofossils have the advantage of being easy to see in the field, but they are rarer, and microfossils are very commonly used by oil prospectors and other industries interested in mineral resources when accurate knowledge of the age of the rocks being looked at is needed.
FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
..... Click the link for more information.
..... Click the link for more information.
FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
..... Click the link for more information.
Ammonites fit these demands well, and are the best-known fossils that have been widely used for this. Other important groups that provide index fossils are the corals, graptolites, brachiopods, trilobites, and echinoids (sea urchins). Conodonts may be identified by experts using light microscopy such that they can be used to index a given sample with good resolution. Fossilized teeth of mammals, have also been used.
Geologists use both large fossils (called macrofossils) and microscopic fossils (called microfossils) for this process, known as biostratigraphy. Macrofossils have the advantage of being easy to see in the field, but they are rarer, and microfossils are very commonly used by oil prospectors and other industries interested in mineral resources when accurate knowledge of the age of the rocks being looked at is needed.
Common Index Fossils
| Fossil | Scientific Name | Time Period | Million Years Ago |
|---|---|---|---|
) Calico Scallop | Pecten gibbus Argopectin gibbus | Quaternary Period | 1.8 MYA |
| Neptunea tabulata | Quaternary Period | 1.8 MYA | |
| Calyptatraphorus velatus | Tertiary Period | ||
| Venericardia planicosta | Tertiary Period | ||
) Scaphites | Scaphites hippocrepis | Cretaceous Period | 144 to 66.4 MYA |
| Inoceramus | Inoceramus labiatus | Cretaceous Period | |
| Perisphinctes | Perisphinctes tiziani | Jurassic Period | |
| Nerinea trinodosa | Jurassic Period | ||
| Trophites subbullatus | Triassic Period | ||
| Monotis subcircularis | Triassic Period | ||
| Leptodus americanus | Permian Period | ||
| Parafusulina | Parafusulina bosei | Permian Period | |
| Dictyocostus americanus | Pennsylvanian Period | ||
| Lophophyllidium proliferum | Pennsylvanian Period | ||
| Cactocrinus multibrachiatus | Mississippian Period | ||
| Prolecanites gurleyi | Mississippian Period | ||
) Mucrospirifer | Mucrospirifer mucronatus | Devonian Period | 416 to 359 MYA |
| Palmatolepus unicornis | Devonian Period | ||
) Ammonite | Ammonite jeletzkytes | Late Silurian to Early Devonian | 400 MYA |
| Cystiphyllum niagarense | Silurian Period | ||
| Hexamoceras hertzeri | Silurian Period | ||
| Trilobite | Bathyurus extans | Ordovician Period | |
| Tetragraptus fructicosus | Ordovician Period | ||
| Paradoxides pinus | Cambrian period | ||
) Trilobite | See list of trilobites | Cambrian Period | 540 MYA |
| Billingselia corrugata | Cambrian Period |
In Popular Culture
Musical Group Bad Religion have a song titled "Part IV (The Index Fossil)" on their 1987 album Suffer. The song suggests that one day humanity will be "an index fossil buried in [its] own debris".References and Links
- For other uses of the term, see Fossil (disambiguation)
FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
..... Click the link for more information.
The geological time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of Earth.
..... Click the link for more information.
..... Click the link for more information.
Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. Sedimentation is the deposition by settling of a suspended material.
..... Click the link for more information.
..... Click the link for more information.
species is one of the basic units of biological classification. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
..... Click the link for more information.
..... Click the link for more information.
..... Click the link for more information.
Corals are marine animals from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals. The group includes the important reef builders that are found in tropical oceans, which secrete calcium carbonate to form a hard
..... Click the link for more information.
..... Click the link for more information.
Graptolithina
Orders
Graptolites
..... Click the link for more information.
Orders
- Dendroidea
- Tuboidea
- Camaroidea
- Crustoidea
- Stolonoidea
- Graptoloidea
- Dithecoidea
Graptolites
..... Click the link for more information.
Brachiopoda
Duméril, 1806
Diversity
About 4000 genera
Subphyla and classes
See Classification
Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) are a nearly extinct, small phylum of benthic invertebrates.
..... Click the link for more information.
Duméril, 1806
Diversity
About 4000 genera
Subphyla and classes
See Classification
Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) are a nearly extinct, small phylum of benthic invertebrates.
..... Click the link for more information.
Trilobita
Walch, 1771
Orders
Trilobites
..... Click the link for more information.
Walch, 1771
Orders
- Agnostida
- Nectaspida
- Redlichiida
- Corynexochida
- Lichida
- Phacopida
- Proetida
- Asaphida
- Harpetida
- Ptychopariida
Trilobites
..... Click the link for more information.
Echinoidea
Leske, 1778
Subclasses
..... Click the link for more information.
Leske, 1778
Subclasses
- Subclass Perischoechinoidea
- Order Cidaroida (pencil urchins)
- Subclass Euechinoidea
..... Click the link for more information.
Conodonta
Groups
Protoconodonta
Paraconodonta
Euconodonta
Conodonts are extinct chordates that form the class Conodonta. For many years, conodonts were known only from enigmatic tooth-like microfossils, which despite their common
..... Click the link for more information.
Groups
Protoconodonta
Paraconodonta
Euconodonta
Conodonts are extinct chordates that form the class Conodonta. For many years, conodonts were known only from enigmatic tooth-like microfossils, which despite their common
..... Click the link for more information.
Microscopy is any technique for producing visible images of structures or details too small to otherwise be seen by the human eye, using a microscope or other magnification tool. It is often used more specifically as a technique of using a microscope.
..... Click the link for more information.
..... Click the link for more information.
- For other uses of the term, see Fossil (disambiguation)
FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
..... Click the link for more information.
Teeth (singular, tooth) are structures found in the jaws (or mouths) of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums.
..... Click the link for more information.
..... Click the link for more information.
Mammalia
Linnaeus, 1758
Subclasses & Infraclasses
..... Click the link for more information.
Linnaeus, 1758
Subclasses & Infraclasses
- Subclass †Allotheria*
- Subclass Prototheria
- Subclass Theria
..... Click the link for more information.
A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology).
..... Click the link for more information.
..... Click the link for more information.
Biostratigraphy is the science of dating rocks by using the fossils contained within them. Usually the aim is correlation. That is, demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at some other section.
..... Click the link for more information.
..... Click the link for more information.
Petroleum (Latin Petroleum derived from Greek πέτρα (Latin petra) - rock + έλαιον (Latin oleum) - oil) or crude oil
..... Click the link for more information.
..... Click the link for more information.
A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties.
..... Click the link for more information.
..... Click the link for more information.
Pectinidae
Linnaeus
Genera
Genus: Argopectin
The Atlantic calico scallop Argopectin gibbus is a medium-sized edible saltwater clam, specifically a scallop, a marine bivalve mollusk.
..... Click the link for more information.
Linnaeus
Genera
Genus: Argopectin
The Atlantic calico scallop Argopectin gibbus is a medium-sized edible saltwater clam, specifically a scallop, a marine bivalve mollusk.
..... Click the link for more information.
Pectinidae
Linnaeus
Genera
Genus: Argopectin
The Atlantic calico scallop Argopectin gibbus is a medium-sized edible saltwater clam, specifically a scallop, a marine bivalve mollusk.
..... Click the link for more information.
Linnaeus
Genera
Genus: Argopectin
The Atlantic calico scallop Argopectin gibbus is a medium-sized edible saltwater clam, specifically a scallop, a marine bivalve mollusk.
..... Click the link for more information.
Quaternary Period is the geologic time period from the end of the Pliocene Epoch roughly 1.806 million years ago to the present. The Quaternary includes 2 geologic subdivisions — the Pleistocene, including Gelasian that used to belong to Pliocene, and the Holocene
..... Click the link for more information.
..... Click the link for more information.
Quaternary Period is the geologic time period from the end of the Pliocene Epoch roughly 1.806 million years ago to the present. The Quaternary includes 2 geologic subdivisions — the Pleistocene, including Gelasian that used to belong to Pliocene, and the Holocene
..... Click the link for more information.
..... Click the link for more information.
Tertiary geological time interval covers roughly the time span between the demise of the non-avian dinosaurs and beginning of the most recent Ice Age, approximately 65 million to 1.8 million years ago.
..... Click the link for more information.
..... Click the link for more information.
Tertiary geological time interval covers roughly the time span between the demise of the non-avian dinosaurs and beginning of the most recent Ice Age, approximately 65 million to 1.8 million years ago.
..... Click the link for more information.
..... Click the link for more information.
Scaphites
Parkinson, 1811
Species
See text.
Scaphites (Greek skafh, "a boat or anything dug or scooped out") is a genus of extinct cephalopod belonging to the family of heteromorph ammonites (suborder Ancyloceratina).
..... Click the link for more information.
Parkinson, 1811
Species
See text.
Scaphites (Greek skafh, "a boat or anything dug or scooped out") is a genus of extinct cephalopod belonging to the family of heteromorph ammonites (suborder Ancyloceratina).
..... Click the link for more information.
The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma).
..... Click the link for more information.
..... Click the link for more information.
Inoceramus
Sowerby, 1814
Species
Several, including:
Inoceramus bellvuensis
Inoceramus biformis
Inoceramus comancheanus
Inoceramus dakotensis
Inoceramus perplexus
Inoceramus pictus
..... Click the link for more information.
Sowerby, 1814
Species
Several, including:
Inoceramus bellvuensis
Inoceramus biformis
Inoceramus comancheanus
Inoceramus dakotensis
Inoceramus perplexus
Inoceramus pictus
..... Click the link for more information.
The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma).
..... Click the link for more information.
..... Click the link for more information.
Perisphinctes
Waagen, 1869
Perisphinctes is an extinct genus of ammonite cephalopod. They lived during the Jurassic Period [1] , and serve as an index fossil for that time period.
..... Click the link for more information.
Waagen, 1869
Perisphinctes is an extinct genus of ammonite cephalopod. They lived during the Jurassic Period [1] , and serve as an index fossil for that time period.
..... Click the link for more information.
This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus
