The Devonian is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at 419.2 million years ago (Ma), to the beginning of the succeeding Carboniferous period at 358.9 Ma. It is the fourth period of both the Paleozoic and the Phanerozoic. It is named after Devon, South West England, where rocks from this period were first studied.
The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian Period, 419.2 Mya. The Silurian is the third and shortest period of the Paleozoic Era, and the third of twelve periods of the Phanerozoic Eon. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out.
Eospirifer is a genus of extinct brachiopod in the class Rhynchonellata (Articulata) and the order Spiriferida. Their fossils occur most commonly in marine calcareous, microbialitic mudstones with extensive mudcracks or shelly packstones, generally mid-Silurian to early-Devonian in age.
Dipleura is a genus of trilobites in the order Phacopida. It was described by Green in 1832, and the type species is Dipleura dekayi. The type locality was in the Hamilton Group in New York.
Bumastus is an extinct genus of corynexochid trilobites which existed from the Early Ordovician period to the Late Silurian period. They were relatively large trilobites, reaching a length of 6 in (15 cm). They were distinctive for their highly globular, smooth-surfaced exoskeleton. They possessed well-developed, large compound eyes and were believed to have dwelled in shallow-water sediments in life.
Gracianella is a genus of fossil brachiopods. It was described by Johnson and Coucot in 1967, and existed from the Silurian to the Devonian of Australia, Austria, Canada, China, the Czech Republic, Italy, Tajikistan, and the United States. A new species, G. paulula, was described by Andrzej Baliński in 2012, from the early Devonian of Ukraine.
Plectodonta is an extinct genus of brachiopods which existed during the Devonian to Silurian of the United States, Australia, Canada, China, the Czech Republic, Czechoslovakia, Germany, Kazakhstan, Morocco, Poland, Spain, Ukraine, Argentina, Bolivia, Sweden, the United Kingdom, and Venezuela. It was described by Kozlowski in 1929, and the type species is P. mariae. A new extinct subspecies, P. mariae pantherae, was described by Andrzej Baliński in 2012, from the early Devonian of Ukraine.
Skenidioides is an extinct genus of brachiopods which existed during the Ordovician, Silurian, and Devonian of what is now Australia, Canada, China, the Czech Republic, Italy, Morocco, Poland, Ukraine, the United States, Belarus, Estonia, Lithuania, Mexico, Norway, Sweden, the United Kingdom, Venezuela, Ireland, Kazakhstan, the Russian Federation, and Argentina. It was described by Schuchert and Cooper in 1931, and the type species is S. billingsi. A new species, S. tatyanae, was described by Andrzej Baliński in 2012, from the early Devonian of Ukraine. The species epithet refers to Tatyana Lvovna Modzalevskaya.
Megistaspis is a genus of trilobites in the order Asaphida and family Asaphidae.
Odontochile is a genus of trilobites in the order Phacopida, family Dalmanitidae.
Crotalocrinites, also known as the feather star, is a genus of extinct sea lily belonging to the family Crotalocrinitidae. These feather stars were stationary intermediate-level organisms feeding on suspension epifauna. They lived in the Silurian period, from the Upper Wenlock age to the Ludlow age.
Holopea is an extinct genus of fossil sea snails, Paleozoic gastropod mollusks in the family Holopeidae.
Panenka is a genus of fossil saltwater clams, marine bivalve molluscs in the family Praecardiidae. Like most bivalves, these molluscs were suspension feeders. They lived in the Devonian Period.
Trimerellida is an extinct order of craniate brachiopods, containing the sole superfamily Trimerelloidea and the families Adensuidae, Trimerellidae, and Ussuniidae. Trimerellidae was a widespread family of warm-water brachiopods ranging from the Middle Ordovician to the late Silurian (Ludlow). Adensuidae and Ussuniidae are monogeneric families restricted to the Ordovician of Kazakhstan. Most individuals were free-living, though some clustered into large congregations similar to modern oyster reefs.
Amplexopora is a genus of bryozoans of the family Amplexoporidae, known in the rock record from the Ordovician to the Permian periods. Species belonging to this genus were stationary epifaunal suspension feeders. Their colonies showed a very great variety in shapes.
The Whitewater Formation is a geologic formation in Ohio and Indiana. It preserves fossils dating back to the Ordovician period.
Odontopleura is a genus of spinose odontopleurid trilobite in the family Odontopleuridae, and is the type genus of that family and of Odontopleurida. The various species are found in Upper Ordovician to Middle Devonian marine strata throughout the world. The best studied fossils are of the type species, O. ovata, from the Wenlock-aged Liteň Formation in Loděnice, in Bohemia, Czech Republic, and, southeastern Gotland, of Sweden.
Strophomenata is an extinct class of brachiopods in the subphylum Rhynchonelliformea.
Acervularia is an extinct genus of horn coral. These stationary epifaunal suspension feeders lived during the Silurian and Devonian periods.
Acervulariidae is an extinct family of horn coral. These stationary epifaunal suspension feeders lived during the Devonian, Silurian and Ordovician periods.
