Related Research Articles
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.
Tentaculites is an extinct genus of conical fossils of uncertain affinity, class Tentaculita, although it is not the only member of the class. It is known from Lower Ordovician to Upper Devonian deposits both as calcitic shells with a brachiopod-like microstructure and carbonaceous 'linings'. The "tentaculites" are also referred to as the styliolinids.
Spiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera it is greatly elongated, giving them a wing-like appearance. They often have a deep fold down the center of the shell. The feature that gives the spiriferids their name ("spiral-bearers") is the internal support for the lophophore; this brachidium, which is often preserved in fossils, is a thin ribbon of calcite that is typically coiled tightly within the shell.
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.
Baragwanathia is a genus of extinct lycopsid plants of Late Silurian to Early Devonian age, fossils of which have been found in Australia, Canada, China and Czechia. The name derives from William Baragwanath who discovered the first specimens of the type species, Baragwanathia longifolia, at Thomson River.
Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to a honeycomb. Adjacent cells are joined by small pores. Their distinguishing feature is their well-developed horizontal internal partitions (tabulae) within each cell, but reduced or absent vertical internal partitions. They are usually smaller than rugose corals, but vary considerably in shape, from flat to conical to spherical.
Acrotretides (Acrotretida) are an extinct order of linguliform brachiopods in the class Lingulata. Acrotretida contains 8 families within the sole superfamily Acrotretoidea. They lived from the Lower Cambrian to the Middle Devonian, rapidly diversifying during the middle Cambrian. In the upper Cambrian, linguliforms reached the apex of their diversity: acrotretides and their relatives the lingulides together comprised nearly 70% of brachiopod genera at this time. Though acrotretides continued to diversify during the Ordovician, their proportional dominance declined, as rhynchonelliforms took on a larger role in brachiopod faunas.
Rhynchonelliformea is a major subphylum and clade of brachiopods. It is roughly equivalent to the former class Articulata, which was used previously in brachiopod taxonomy up until the 1990s. These so-called articulated brachiopods have many anatomical differences relative to "inarticulate" brachiopods of the subphyla Linguliformea and Craniformea. Articulates have hard calcium carbonate shells with tongue-and-groove hinge articulations and separate sets of simple opening and closing muscles.
Tentaculita is an extinct class of lophophorates ranging from the Early Ordovician to the Middle Jurassic. They were suspension feeders with a near worldwide distribution. For a more thorough discussion, see Tentaculites.
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.
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.
Athyridida is an order of Paleozoic brachiopods included in the Rhynchonellata, which makes up part of the articulate brachiopods.
Meristella is an extinct genus of brachiopods found from the Late Silurian to the Late Devonian. They are characterized by a smooth oval shell and a prominent incurved beak on the pedicle valve. Meristella is placed in the family Meristellidae of the articulate brachiopod order Athyridida.
Cincinnetina is an extinct genus of brachiopods which existed in what is now the United States during the Late Ordovician. It was described by Jisuo Jin in 2012, as a new genus for the Orthis species O. multisecta and O. meeki, each of which have been replaced a number of times under other genera, e.g. Dalmanella, Resserella, and Onniella by other authors. A third species, C. minnesotensis, was described from Minnesota, from which its species epithet was derived.
Strophomena is a genus of brachiopods belonging to the order Strophomenida family Strophomenidae, named by Rafinesque in 1824. They were stationary epifaunal suspension feeders.
Paleontology in Wisconsin refers to paleontological research occurring within or conducted by people from the U.S. state of Wisconsin. The state has fossils from the Precambrian, much of the Paleozoic, some a parts of the Mesozoic and the later part of the Cenozoic. Most of the Paleozoic rocks are marine in origin. Because of the thick blanket of Pleistocene glacial sediment that covers the rock strata in most of the state, Wisconsin’s fossil record is relatively sparse. In spite of this, certain Wisconsin paleontological occurrences provide exceptional insights concerning the history and diversity of life on Earth.
Cyrtospirifer is an extinct genus of brachiopods. The fossils are present in the Middle and Upper Devonian.
Gertruda Józefa Biernat was a Polish geologist and paleontologist. During World War II, she joined the Polish resistance, participating in the Warsaw Uprising. She is noted for her work in identifying and studying brachiopods of the Ordovician period of the Paleozoic Era, and several have been named in her honor. Biernat worked at institutions of the Polish Academy of Sciences, published major works on brachiopods, participating in paleontological expeditions internationally, including leading a series of expeditions in the Arctic.
Atrypida is an extinct order of rhynchonelliform brachiopods. They first appeared in middle Ordovician and survived the Ordovician-Silurian extinction, becoming the dominant brachiopods of the Silurian alongside the order Pentamerida. They would survive into the Late Devonian before going extinct at the end of the Frasnian.
References
- ↑ Andrzej Baliński (2012). "The brachiopod succession through the Silurian–Devonian boundary beds at Dnistrove, Podolia, Ukraine". Acta Palaeontologica Polonica. 57 (4): 897–924. doi: 10.4202/app.2011.0138 .