"A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, and DNA remnants."
Explanation of how fossils are formed, including preservation in sediment, mineral replacement, and mould and cast formation.
Sedimentology: Study of the physical and chemical characteristics of sedimentary rocks and their formation. This is important as fossilization mostly occurs in sedimentary rocks.
Taphonomy: Study of the processes that lead to the preservation of fossils. Understanding taphonomy helps in determining the accuracy of the fossil record.
Diagenesis: Study of the physical and chemical changes that occur in sedimentary rocks after deposition. It is important to understand diagenesis to understand the changes fossils undergo after deposition.
Paleobiology: Study of the biology of extinct organisms. Understanding paleobiology helps in interpreting the fossils and reconstructing the past.
Evolution: Study of how species change over time. It is important to understand evolution to understand the relationships between different organisms.
Biogeography: Study of the distribution of organisms and how they have changed over time. It helps in understanding the geologic processes that have affected life on earth.
Stratigraphy: Study of the layers of rocks and their chronological order. Understanding stratigraphy helps in understanding the context of fossils.
Paleoclimate: Study of the past climate on earth. Understanding the climate of the past helps in reconstructing the paleoenvironmental conditions in which the organisms lived.
Morphology: Study of the form and structure of organisms. Understanding morphology helps in identifying and classifying fossils.
Phylogenetics: Study of the evolutionary relationships between different organisms. It helps in understanding the evolutionary history of life on earth.
Biostratigraphy: Study of the identification and correlation of fossils in different rock layers. It helps in determining the age of rocks.
Fossilization modes: Various modes of fossilization such as petrification, carbonization, impression, and mold, and cast. Understanding the different modes of fossilization helps in recognizing the different types of fossils.
Permineralization: This occurs when minerals fill in pore spaces and other voids within an organism's tissues, creating a solid, mineralized replica of the original organism.
Carbonization: This process involves the compression and loss of volatile organic compounds in an organism's tissues, leaving behind a thin film of carbon that preserves the original shape and texture of the organism.
Recrystallization: In this type of fossilization, minerals within an organism's tissues are replaced over time by new, larger crystals, which preserve the original shape and form of the organism.
Replacement: This process involves the complete substitution of an organism's original organic materials with new minerals, so that the resulting fossil retains the original shape and texture of the organism, but is composed entirely of inorganic materials.
Mold Fossils: This occurs when an organism's remains are compressed or otherwise distorted by sedimentary processes, leaving behind a void or impression in the surrounding rock that preserves the outline of the original organism.
Cast Fossils: This type of fossil is created when sediment fills in the void left by a mold fossil, creating a three-dimensional replica of the original organism.
Trace Fossils: This category includes any fossilized evidence of an organism's activities, including footprints, burrows, and other marks left behind in sedimentary deposits.
Concretion: This process involves the gradual accumulation of minerals around an original organism, eventually resulting in a hard, spherical or disk-shaped fossil.
Pyritization: This type of fossilization is characterized by the preservation of a fossil within a pyrite (fool's gold) mineral deposit, resulting in the formation of a shiny, brassy-looking fossil.
Bioimmuration: In this type of fossilization, an organism is preserved inside the protective shell or exoskeleton of another organism, resulting in the preservation of both.
Permineralized Wood: This is a type of fossilization that affects only woody plant materials, resulting in the preservation of the original shape and texture of the wood, but with the replacement of organic materials by minerals.
Petrification: This process involves the complete replacement of an organism's original materials with stone or mineral, resulting in a fossil that is indistinguishable from the surrounding rock in both composition and texture.
"Paleontology is the study of fossils: their age, method of formation, and evolutionary significance."
"Specimens are usually considered to be fossils if they are over 10,000 years old."
"The oldest fossils are around 3.48 billion years old to 4.1 billion years old."
"The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils."
"The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host."
"There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, carbonization, and bioimmuration."
"Fossils vary in size from one-micrometre (1 µm) bacteria to dinosaurs and trees, many meters long and weighing many tons."
"A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates."
"These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils."
"Some fossils are biochemical and are called chemofossils or biosignatures."
"Paleontology is the study of fossils: their age, method of formation, and evolutionary significance."
"Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, and DNA remnants."
"Specimens are usually considered to be fossils if they are over 10,000 years old."
"The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host."
"There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, carbonization, and bioimmuration."
"These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils."
"Some fossils are biochemical and are called chemofossils or biosignatures."
"Fossils vary in size from one-micrometre (1 µm) bacteria to dinosaurs and trees, many meters long and weighing many tons."
"Paleontology is the study of fossils: their age, method of formation, and evolutionary significance."