Glossary

Ammonite: An extinct group of molluscs with multi-chambered, typically spiral shells, that lived from 400 to 66 million years ago.
Angiosperm: Flowering plant.
Apex predator: Predator that is at the top of the food chain, and not preyed upon by other animals. Also known as alpha, or top predator.
Arthropod: An animal, such as a spider, insect, or lobster, which has an exoskeleton, a segmented body, and jointed appendages.
Articulate: Having jointed segments or bodies.
Baculite: A variant subgroup of ammonites with nearly straight shells.
Concretion: Rock-like mass of sediment, usually spherical or ovoid, that forms in layers around a ‘nucleus’, such as a small fossil.
Conifer: A tree that has cones and either evergreen needles, or scale-like leaves.
Cretaceous: The last of the three periods of the Mesozoic era, which followed the Jurassic Period and lasted from 145 to 66 million years ago. Ended with a mass extinction event (called the Cretaceous–Paleogene extinction event) that killed all non-avian dinosaurs, among other groups.
Cyanobacteria: Bacteria that live in moist environments and produce oxygen by photosynthesis.
Eocene: The second of three epochs in the Paleogene period of the Cenozoic era. This epoch lasted from 55 to around 33.9 million years ago.
Extinct: Having no members of a species living today.
Genus (Plural, Genera): A category in the classification system of organisms. A genus includes closely related species, and is the first term in the two-term (binomial) naming system of species (e.g. humans = Homo sapiens)
Gymnosperm: A seed-bearing, woody plant such as a conifer, in which seeds are not contained within a fruit, but develop on the outside of the plant’s scales or leaves.
Heteromorph: A group of ammonites whose shells are not arranged in the typical coiled spiral shape. Baculites, with their straight shells, belong to this group.
Holocene: The current geological epoch, which began around 11,650 years ago, at the end of the last Ice Age.
Metacarpal: Any of the bones of an animal’s forelimb that is equivalent to one of the five bones in the human hand.
Microfossil: A fossil that cannot be seen without the use of a microscope.
Paleoarchean: Geologic era that lasted from 3600 to 3200 million years ago. At this point in time, the only life that exists is single-celled bacteria.
Permineralization: A fossilization process in which internal casts of organisms are formed by deposits of minerals that are carried by water into organic tissue, and fill spaces within the tissue.
Petrification: The process in which organic material becomes a fossil. This is done through the replacement of organic material by minerals (i.e, permineralization).
Phalanges: The bones that make up the fingers or toes of an animal.
Photosynthesis: The process of converting light energy into chemical energy which can be used to power an organism.
Plate tectonics: A scientific theory describing the movement of the plates of the Earth’s crust.
Pleistocene: The first epoch of the Quarternary period of the Cenozoic era. This epoch lasted from about 2.6 million years to 11,700 years ago.
Radiocarbon dating: A method for determining the age of an organic object. Done by measuring the amount of radiocarbon (14C) in the object.
Recrystallization: A metamorphic process in which atoms of a mineral such as limestone, under the effects of pressure and temperature, are reorganized.
Stratigraphy: A branch of geology, dedicated to the study of strata (layers of rock) and how they are layered. One of its subfields, biostratigraphy, is particularly relevant to paleontology as it is based on fossil evidence that is found within the rock layers.
Stromatolites: Layered sedimentary rocks that were originally formed by the growth of successive layers of cyanobacteria. Fossilized stromatolites represent some of the earliest life on our planet, with the oldest being around 3.7 billion years old.
Trilobites: Early arthropods that thrived from the early Cambrian (around 520 million years ago) to the end of the Permian (around 250 million years ago). Their lifestyles and body structures varied from species to species, but all had a segmented exoskeleton with three distinct lobes, and jointed limbs.

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