Fossils & Geologic Time, ENA-LAR

Geologic time is the extensive interval of time occupied by the geologic history of Earth. Formal geologic time begins at the start of the Archean Eon (4.0 billion to 2.5 billion years ago) and continues to the present day.
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Fossils & Geologic Time Encyclopedia Articles By Title

Enaliarctos
Enaliarctos, extinct genus of mammals that contains the oldest known member of Pinnipedia, the group that contains......
Endothyra
Endothyra, extinct genus of Foraminifera, protozoans with a readily preservable shell; found as fossils in Devonian......
Eocene Epoch
Eocene Epoch, second of three major worldwide divisions of the Paleogene Period (66 million to 23 million years......
Eohippus
Eohippus, (genus Hyracotherium), extinct group of mammals that were the first known horses. They flourished in......
Eospermatopteris
Eospermatopteris, genus of extinct plants known from fossil stumps discovered in the 1870s near Gilboa, New York,......
Eospirifer
Eospirifer, genus of extinct brachiopods, or lamp shells, found as fossils in Middle Silurian to Lower Devonian......
Eryops
Eryops, genus of extinct primitive amphibians found as fossils in Permian rocks in North America (the Permian period......
Euoplocephalus
Euoplocephalus, (genus Euoplocephalus), armoured North American dinosaur of the Late Cretaceous Period (99.6 million......
Euparkeria
Euparkeria, extinct genus of reptile very closely related to the ancestral archosaurs (a group containing present-day......
Euphemites
Euphemites, extinct genus of gastropods (snails) abundant during the Late Carboniferous Period (between 320 and......
Europasaurus
Europasaurus, genus representing one of the smallest known sauropod dinosaurs, characterized by a distinctive arched......
Eusthenopteron
Eusthenopteron, genus of extinct lobe-finned fishes (crossopterygians) preserved as fossils in rocks of the late......
faunal succession, law of
law of faunal succession, observation that assemblages of fossil plants and animals follow or succeed each other......
Favosites
Favosites, extinct genus of corals found as fossils in marine rocks from the Ordovician to the Permian periods......
feathered dinosaur
feathered dinosaur, any of a group of theropod (carnivorous) dinosaurs, including birds, that evolved feathers......
Fenestella
Fenestella, genus of extinct bryozoans, small colonial animals, especially characteristic of the Early Carboniferous......
Fig Tree microfossils
Fig Tree microfossils, assemblage of microscopic structures uncovered in the Fig Tree Series, a rock layer at least......
fission-track dating
fission-track dating, method of age determination that makes use of the damage done by the spontaneous fission......
Fontéchevade
Fontéchevade, a cave site in southwestern France known for the 1947 discovery of ancient human remains and tools......
fossil
fossil, remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in Earth’s......
fossil record
fossil record, history of life as documented by fossils, the remains or imprints of organisms from earlier geological......
Fusulina
Fusulina, genus of extinct fusulinid foraminiferans (protozoans with a shell) found as fossils in marine rocks......
Fusulinella
Fusulinella, genus of extinct fusulinid foraminiferans (protozoans with a shell) found as fossils in Late Carboniferous......
fusulinid
fusulinid, any of a large group of extinct foraminiferans (single-celled organisms related to the modern amoebas......
Ganlea megacanina
Ganlea megacanina, extinct primate species belonging to the family Amphipithecidae and known only from fossils......
Gastrioceras
Gastrioceras, genus of extinct cephalopods (animals related to the modern squid, octopus, and nautilus), found......
geologic time
geologic time, the extensive interval of time occupied by the geologic history of Earth. Formal geologic time begins......
Gervais, Paul
Paul Gervais was a paleontologist and zoologist who succeeded Georges Cuvier and Henri de Blainville as the principal......
giant water scorpion
giant water scorpion, any member of the extinct subclass Eurypterida of the arthropod group Merostomata, a lineage......
Gibraltar remains
Gibraltar remains, Neanderthal fossils and associated materials found at Gibraltar, on the southern tip of Spain.......
Giganotosaurus
Giganotosaurus, (Giganotosaurus carolinii), genus of a large theropod dinosaur in the family Carcharodontosauridae......
Gigantopithecus
Gigantopithecus, (Gigantopithecus blacki), genus of large extinct apes represented by a single species, Gigantopithecus......
Glossopteris
Glossopteris, genus of fossilized woody plants known from rocks that have been dated to the Permian and Triassic......
Glyptodon
Glyptodon, genus of extinct giant mammals related to modern armadillos and found as fossils in deposits in North......
gomphothere
gomphothere, any member of a line of extinct elephants that formed the most numerous group of the order Proboscidea......
Goniophora
Goniophora, extinct genus of clams found in Silurian to Devonian rocks (the Silurian Period began 444 million years......
Gorstian Stage
Gorstian Stage, first of two stages of the Ludlow Series, made up of all rocks deposited during the Gorstian Age......
Gould, Stephen Jay
Stephen Jay Gould was an American paleontologist, evolutionary biologist, and science writer. Gould graduated from......
Grabau, Amadeus William
Amadeus William Grabau was an American geologist and paleontologist, known for his works on paleoecology and Chinese......
Grand Canyon Series
Grand Canyon Series, major division of rocks in northern Arizona dating from Precambrian time (about 3.8 billion......
graptolite
graptolite, any member of an extinct group of small, aquatic colonial animals that first became apparent during......
Greenops
Greenops, genus of trilobites (extinct arthropods) found as fossils in Middle and Upper Devonian deposits (the......
Griffith, Sir Richard John, 1st Baronet
Sir Richard John Griffith, 1st Baronet was an Irish geologist and civil engineer who has sometimes been called......
Gunflint microfossils
Gunflint microfossils, assemblage of microscopic fossils uncovered in the Gunflint Iron Formation, a rock layer......
Gzhelian Stage
Gzhelian Stage, last of four internationally defined stages of the Pennsylvanian Subsystem of the Carboniferous......
Hadean Eon
Hadean Eon, informal division of Precambrian time occurring between about 4.6 billion and about 4.0 billion years......
Hall, James
James Hall was an American geologist and paleontologist who was a major contributor to the geosynclinal theory......
Hallopora
Hallopora, genus of extinct bryozoans (moss animals) found as fossils in Ordovician to Silurian marine rocks (from......
Halysites
Halysites, extinct genus of corals found as fossils in marine rocks from the Late Ordovician Period to the end......
Haug, Émile
Émile Haug was a French geologist and paleontologist known for his contributions to the theory of geosynclines......
Hay, Oliver Perry
Oliver Perry Hay was an American paleontologist who did much to unify existing knowledge of North American fossil......
Heliophyllum
Heliophyllum, genus of extinct coral found as fossils in Devonian marine rocks (the Devonian Period began 416 million......
helium dating
helium dating, method of age determination that depends on the production of helium during the decay of the radioactive......
Herrerasaurus
Herrerasaurus, (genus Herrerasaurus), primitive carnivorous dinosaur or close relative of dinosaurs found as fossils......
Hesperornis
Hesperornis, (genus Hesperornis), extinct birds found as fossils in Late Cretaceous Period deposits dating from......
Hesperorthis
Hesperorthis, extinct genus of brachiopods, or lamp shells, which as fossils are especially characteristic of Ordovician......
Homo erectus
Homo erectus, extinct species of the human genus (Homo), perhaps an ancestor of modern humans (Homo sapiens). H.......
Homo floresiensis
Homo floresiensis, taxonomic name given to an extinct hominin (member of the human lineage) that is presumed to......
Homo habilis
Homo habilis, extinct species of human, the most ancient representative of the human genus, Homo. Homo habilis......
Homo heidelbergensis
Homo heidelbergensis, extinct species of archaic human (genus Homo) known from fossils dating from 600,000 to 200,000......
Homo naledi
Homo naledi, extinct species of human, initially thought to have evolved about the same time as the emergence of......
horn coral
horn coral, any coral of the order Rugosa, which first appeared in the geologic record during the Ordovician Period,......
Hrdlička, Aleš
Aleš Hrdlička was a physical anthropologist known for his studies of Neanderthal man and his theory of the migration......
Huronian System
Huronian System, major division of Precambrian rocks in North America (the Precambrian began about 3.8 billion......
Huxley, Thomas Henry
Thomas Henry Huxley was an English biologist, educator, and advocate of agnosticism (he coined the word). Huxley’s......
Hyaenodon
Hyaenodon, extinct genus of carnivorous mammals that first appeared in the fossil record about 42 million years......
Hyatt, Alpheus
Alpheus Hyatt was an American zoologist and paleontologist who achieved eminence in the study of invertebrate fossil......
Hypsilophodon
Hypsilophodon, (genus Hypsilophodon), small to medium-sized herbivorous dinosaurs that flourished about 115 million......
Icadyptes
Icadyptes, genus of extinct giant penguin that lived about 37 million to 35 million years ago, during the second......
Ichthyornis
Ichthyornis, (order Ichthyornithiformes), extinct seabird of the Late Cretaceous Period (99.6 million to 66 million......
ichthyosaur
ichthyosaur, any member of an extinct group of aquatic reptiles, most of which were very similar to porpoises in......
Ichthyostega
Ichthyostega, genus of extinct animals, closely related to tetrapods (four-legged land vertebrates) and found as......
Ida
Ida, (Darwinius masillae), nickname for the remarkably complete but nearly two-dimensional skeleton of an adapiform......
Iguanodon
Iguanodon, (genus Iguanodon), large herbivorous dinosaurs found as fossils from the Late Jurassic and Early Cretaceous......
index fossil
index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular......
Indricotherium
Indricotherium, genus of giant browsing perissodactyls found as fossils in Asian deposits of the Late Oligocene......
ionium-thorium dating
ionium-thorium dating, method of establishing the time of origin of marine sediments according to the amount of......
Irish elk
Irish elk, (Megaloceros giganteus), extinct species of deer, characterized by immense body size and wide antlers,......
Isotelus
Isotelus, genus of trilobites (extinct arthropods) restricted to Europe and North America during the Ordovician......
John Day Fossil Beds National Monument
John Day Fossil Beds National Monument, series of rock formations in north-central Oregon, U.S., consisting of......
Jurassic Period
Jurassic Period, second of three periods of the Mesozoic Era. Extending from 201.3 million to 145 million years......
Kabwe cranium
Kabwe cranium, fossilized skull of an extinct human species (genus Homo) found near the town of Kabwe, Zambia (formerly......
Karoo System
Karoo System, geologic system of rocks outcropping over a 1,560,000-square-kilometer (600,000-square-mile) area......
Kasimovian Stage
Kasimovian Stage, third of four internationally defined stages of the Pennsylvanian Subsystem of the Carboniferous......
Katangan Complex
Katangan Complex, major division of late Precambrian rocks (the Precambrian era began about 4.6 billion years ago......
Kebara
Kebara, paleoanthropological site on Mount Carmel in northern Israel that has yielded a trove of Neanderthal bones......
Keweenawan System
Keweenawan System, division of late Precambrian rocks and time in North America (the Precambrian began about 4.6......
Kidston, Robert
Robert Kidston was an English paleobotanist, noted for his discoveries and descriptions of plant fossils from the......
Knowlton, Frank Hall
Frank Hall Knowlton U.S. paleobotanist and pioneer in the study of prehistoric climates based on geologic evidence,......
Koro Toro
Koro Toro, site of paleoanthropological excavations in central Chad, best known for a fossilized fragment of a......
Krapina remains
Krapina remains, fossilized remains of at least 24 early Neanderthal adults and children, consisting of skulls,......
Kungurian Stage
Kungurian Stage, last of the four stages of the Lower Permian (Cisuralian) Series, encompassing all rocks deposited......
La Brea Tar Pits
La Brea Tar Pits, tar (Spanish brea) pits, in Hancock Park (Rancho La Brea), Los Angeles, California, U.S. The......
La Chapelle-aux-Saints
La Chapelle-aux-Saints, cave site near the village of La Chapelle-aux-Saints in central France where the bones......
La Ferrassie
La Ferrassie, paleoanthropological site in the Dordogne region of France where Neanderthal fossils were found in......
Lagar Velho
Lagar Velho, site near Leiria, central Portugal, where the buried skeleton of a four-year-old child, dating to......
Lambeosaurus
Lambeosaurus, (genus Lambeosaurus), duck-billed dinosaur (hadrosaur) notable for the hatchet-shaped hollow bony......
Lartet, Édouard
Édouard Lartet was a French geologist, archaeologist, and a principal founder of paleontology. He is credited chiefly......

Fossils & Geologic Time Encyclopedia Articles By Title