Fossils

Fossils

Fossil Preservation

The process of maintaining and protecting the remains of organisms in a recognizable form.

Rapid Burial

A condition favoring fossil preservation which protects remains from decay and environmental conditions.

Hard Parts

Structures such as bones, teeth, and shells that fossilize better than soft tissues.

Low Oxygen Environments

Areas that inhibit decay by slowing microbial activity, common in deep-sea floors.

Petrification

A mode of fossil preservation where organism material is replaced or filled with minerals.

Permineralization

A process where minerals fill pores or cavities in organic material, often seen in bones and wood.

Casts and Molds

Fossil types that include external molds (impressions of the exterior) and internal molds (formed inside hollow structures).

Carbonization

A mode of preservation where organic materials are compressed under heat and pressure, leaving a carbon residue.

Unaltered Remains

Fossils that retain original material, such as shells, teeth, and bones.

Encasement in Amber

A preservation method where organisms are trapped in tree resin, often preserving fine details.

Mummification

The preservation of organisms in arid environments through drying of tissues.

Radiometric Dating

A technique that measures the radioactive decay of isotopes to determine the age of fossils.

Law of Superposition

In undisturbed layers, the oldest rocks are at the bottom and the youngest at the top.

Faunal Succession

A principle stating that fossils follow a predictable sequence in layered rocks.

Chronological Order of Geological Time

The arrangement of eons, eras, periods, and epochs in Earth’s history.

Phanerozoic Eon

A geological eon characterized by abundant fossil evidence and divided into eras.

Mass Extinctions

Significant events marking the loss of large numbers of species in a relatively short period.

Fossil-Bearing Sedimentary Rocks

Types of rocks that commonly contain fossils, such as limestone, sandstone, and shale.

Trophic Roles

The various roles organisms play in the food chain, such as producers, predators, and scavengers.

Benthic Life Modes

Life forms that inhabit the sea floor, including infaunal and epifaunal organisms.

Planktonic Organisms

Floating organisms that drift in water, as opposed to nektonic active swimmers.

Trace Fossils (Ichnofossils)

Fossils that provide evidence of an organism's behavior, like tracks and burrows.

Hip Height Calculation

A formula used to estimate an organism's hip height based on the length of its footprints.

Head-to-Tail Length Calculation

A method to estimate the length of an organism from the length of its footprint.

Relative Speed Ratio

A calculation used to determine the relative speed of dinosaurs based on stride and hip height.

Tar Preservation

The process where sticky tar traps and preserves entire organisms, often seen at La Brea Tar Pits.

Silicification

A fossilization process where silica replaces the organic material of an organism.

Pyritization

A type of fossil preservation where pyrite replaces organic tissues in low-oxygen environments.

Phosphatization

A preservation method where phosphate minerals replace soft tissues or bones.

Carbonate Rocks

Sedimentary rocks primarily made of carbonate minerals, often rich in marine fossils.

Chert

A silica-rich sedimentary rock known for preserving microfossils like radiolarians.

Coquina

A type of limestone composed primarily of shell fragments cemented together.

Marine Environments

Habitats that include shallow reefs, lagoons, and deep ocean areas.

Terrestrial Environments

Land-based habitats such as forests, grasslands, and deserts.

Freshwater Environments

Habitats that include bodies of water like lakes, rivers, and swamps.

Tiktaalik

A significant fossil that represents the transition from fish to tetrapods.

Archaeopteryx

A key fossil that demonstrates the evolutionary link between dinosaurs and birds.

Lagerstätten Sites

Locations known for exceptionally preserved fossils, such as Burgess Shale.

Detritivores

Organisms that feed on dead organic matter and contribute to nutrient recycling.

Vagrant Life Modes

Mobile organisms that move actively in their environment.

Sessile Life Modes

Organisms that are stationary and do not move from their location.

Infaunal Life Modes

Organisms that live buried within sediments.

Epifaunal Life Modes

Organisms that live on the surface of sediments.

Surface Impressions

Fossil traces that capture the outline of organisms, such as plant leaves.

Natural Disasters

Events like landslides and volcanic eruptions that contribute to rapid burial of organisms.

Durability Bias

The tendency for hard-bodied organisms to be better represented in the fossil record.

Aquatic Organisms Preservation Advantage

Aquatic organisms have a higher chance of fossilization due to sedimentation.

Physical Destruction of Fossils

Processes like erosion and metamorphism that can damage or destroy fossils.

Subduction Zones

Areas where tectonic plates collide, often leading to fossil destruction.

Sediment Deposition

The process of sediment settling and accumulating in bodies of water, aiding fossil preservation.