Fossils

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Fossils Noun

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[fos-uhls]

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Fossils

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The remains or traces of ancient life, usually buried in rock, providing evidence of Earth's history and evolution.

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Example: This image shows different types of fossils, including the preserved skeletal remains of a fish and a dinosaur, and the impression of a plant.

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Paleontology Noun

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[pey-lee-on-tol-uh-jee]

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Paleontology

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The scientific study of ancient life, from dinosaurs to prehistoric plants, primarily through the detailed examination of fossils.

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Example: This diagram shows that older fossils are found in deeper rock layers (strata), while younger fossils are in layers closer to the surface.

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Paleontologist Noun

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[pey-lee-on-tol-uh-jist]

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Paleontologist

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A scientist who finds and studies fossils to understand the complex and extensive history of life on Earth.

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Example: A paleontologist is a scientist who studies fossils, shown here carefully excavating a dinosaur skeleton from the earth with special tools.

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Evolution Noun

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[ev-uh-loo-shun]

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Evolution

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The process by which species change over long periods of time, with fossil evidence revealing these gradual transformations.

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Example: This diagram shows how different animal groups are related through common ancestors, with fossils like Tiktaalik providing key evidence for evolutionary transitions.

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Sedimentary Rock Noun

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[sed-uh-men-tuh-ree rok]

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Sedimentary Rock

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A type of rock formed from the deposition, compaction, and cementation of sediment, in which most fossils are found.

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Example: This sedimentary rock is made of many small fossil fragments, like ancient shells and skeletons, that have been naturally cemented together over millions of years.

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Sedimentation Noun

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[sed-uh-men-tey-shun]

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Sedimentation

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The process in which eroded sediments settle, often in water, forming layers that can eventually become sedimentary rock.

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Example: Over time, particles like sand and silt that are suspended in water will settle to the bottom, forming a layer of sediment.

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Compaction Noun

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[kuhm-pak-shun]

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Compaction

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The process where layers of sediment are pressed together by the weight of overlying layers, squeezing out trapped water.

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Example: This diagram shows that when a heavy load or pressure is applied to loose particles (like soil or sediment), the particles are pressed tightly together, reducing the space between them.

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Cementation Noun

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[see-men-tey-shun]

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Cementation

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The process in which dissolved minerals crystallize and glue particles of sediment together to form solid sedimentary rock.

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Example: This diagram shows how natural mineral 'cement' fills the empty spaces between sediment particles, gluing them together to form solid sedimentary rock.

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Strata Noun

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[strah-tuh]

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Strata

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Distinct layers of rock, where deeper layers are generally older than those found closer to the Earth's surface.

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Example: This diagram shows a cross-section of the Earth with distinct horizontal layers of rock, called strata, stacked on top of each other.

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Mineral Replacement Noun

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[min-er-uhl ri-pleys-muhnt]

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Mineral Replacement

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A fossilization process where minerals from groundwater fill the spaces of an organism's hard parts like bones or shells.

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Example: This petrified wood shows how minerals replaced the original organic material, preserving the tree's growth rings in stone and creating a fossil.