|
Fish Bed Formation
The Fish Bed Formation is a geological formation in Scotland, United Kingdom. The fluvial to lacustrine sandstones, shales, siltstones and conglomerates preserve flora, arthropods, among which eurypterids, invertebrates and early fish fossils dating back to the Wenlock epoch of the Silurian period.Fish Bed Formation at .org Description 
The fish beds are contained within red-bed sequences comprising conglome ...
[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, 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. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods ( myriapods, arachnids and hexapods) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ateleaspis
''Ateleaspis'' is an extinct genus of primitive ostracoderm fish that lived in the Silurian period ( Wenlock Epoch) to the Lower Devonian. Like other ostracoderms, ''Ateleaspis'' had a head shield similar to that of '' Cephalaspis''. Species from Silurian period were found in Norway and Scotland, but now has been found also in Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ... from Early Devonian period. Description ''Ateleaspis'' possibly is the most basal vertebrate with paired fins. ''Ateleaspis'' was a small fish (about 15 – 20 cm) and had a flat headshield and a narrow trunk covered by brick-like scales. References External links Ateleaspis at PalaeosAteleaspis species location & chronology Osteostraci genera Paleozoic jawless fish Fossils of Norwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hughmilleria
''Hughmilleria'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Hughmilleria'' have been discovered in deposits of the Silurian age in China and the United States. Classified as part of the basal family Hughmilleriidae, the genus contains three species, ''H. shawangunk'' from the eastern United States, ''H. socialis'' from Pittsford, New York, and ''H. wangi'' from Hunan, China. The genus is named in honor of the Scottish geologist Hugh Miller. ''H. socialis'' is the type species of Hughmilleriidae, a eurypterid family classified in the superfamily Pterygotioidea that is differentiated by their streamlined bodies, the enlargement of their medium-sized chelicerae and the presence of paired Spine (zoology), spines on the walking appendages. With the biggest specimen measuring 20 centimetres (8 inches) in length, ''Hughmilleria'' is considered a eurypterid of small size. Description ''Hughmilleria'' is the most basal (primitive) known member of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parastylonurus
''Parastylonurus'' is a genus of prehistoric eurypterid. It is classified within the Parastylonuridae family and contains three species, ''P. hendersoni'' and ''P. ornatus'' from the Silurian of Scotland and ''P. sigmoidalis'' from the Silurian of England.Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF). Description ''Parastylonurus'' was a stylonuroid of small to medium size with a rounded prosoma wider than it was long. The eyes were located on the anterior half of the carapace and the metasoma was very long. The first three walking legs were very short with single opposable spines on every joint. The last two walking legs were very long, reaching to the last tergite. The opisthosoma was narrow and undifferentiated and the telson was spike-like. Classification ''Para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanarkopterus
''Lanarkopterus'' is a genus of prehistoric eurypterid with one recognised species, ''Lanarkopterus dolichoschelus''. ''Lanarkopterus'' was long seen as a species of the closely related '' Mixopterus'', though more complete specimens discovered in the 1960s determined that it differed in several aspects, enough to warrant a separate genus. Specimens of the genus have been recovered from deposits of Late Silurian age in Scotland. Description ''Lanarkopterus'' was a small to moderately large (ranging in size from less than 10 centimeters to over 30 centimeters) mixopterid eurypterid that like its close relative '' Mixopterus'' appeared almost scorpion-like with a broad and trilobed preabdomen, a narrow and tapering postabdomen and a sharped and curved telsonic spine. History of discovery Specimens of ''Lanarkopterus'' were first noted by Peach and Horne (1899) in the Ludlowian fish beds of the Lesmahagow and Hagshaw Hills Silurian inliers in Ayrshire and Lanarkshire, Scotlan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casiogrammus
''Casiogrammus'' is an extinct genus of millipede in the family Zosterogrammidae. There is one described species in ''Casiogrammus'', ''C. ichthyeros''. References Millipedes Millipedes of North America Articles created by Qbugbot {{paleo-myriapod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lasanius
''Lasanius'' is a genus of basal jawless fish from the Early Silurian, around 443.8 million years ago, known from fossils found near Lesmahagow, Scotland. Specimens range from 13.3 to 74.5 mm in length. ''Lasianus'' has a pair of eyes, and a notochord, and while it has rows of bony scutes running along its back, it lacks the armour typical of other Paleozoic jawless fish like ostracoderms. There are also structures close to the front of the animal dubbed "chains" and "rods", of unclear function. At the end of the body a hypocercal tail fin was present in the form of a caudal lobe. Historically, it has often been allied with the anaspids, though other studies found it to be unrelated. A comprehensive redescription published in 2023 found that it was a stem-group cyclostome, more closely related to hagfish and lampreys than to jawed fish Gnathostomata (; from Ancient Greek: (') 'jaw' + (') 'mouth') are jawed vertebrates. Gnathostome diversity comprises roughly 60,000 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanarkia
''Lanarkia'' is a genus of extinct thelodont agnathan which existed in what is now Scotland and Canada during the upper Silurian period.''Lanarkia horrida'' at www.fossilmuseum.net. Description Lanarkia were very small fish specifically 30-45 cm in length that would have been possible prey toeurypterids
Eurypterids, often informally called sea scorpions, are a group of extinct marine arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period, 467.3 million years ago. The ... .
References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkenia
''Birkenia'' is a genus of extinct Anaspida, anaspid fish from Middle Silurian strata of Northern Europe, and Middle Silurian to possibly Earliest Devonian strata of Arctic Canada.Blom, Henning, T. Märss, and C. G. Miller. "Silurian and earliest Devonian birkeniid anaspids from the Northern Hemisphere." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 92.03 (2001): 263-323/ref> Birkeniid anaspids are covered by a series of small plates on the head and rod-shaped scales in a cheveron-like pattern on the trunk. Intact fossil specimens of ''B. elegans'' suggest the living animal reached a length of up to , and was an active swimmer. In addition to whole specimens and scale microfossils of ''B. elegans'', which are found in Great Britain and Scandinavia, scales of a second species, ''B. robusta,'' are found in Late Silurian strata of Scandinavia and Estonia. The scales of ''B. robusta'' differ from those of ''B. elegans'' in that, as the specific e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
