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Sarcoprion
''Sarcoprion'' (from the Ancient Greek for "flesh saw") is an extinct genus of eugeneodontid holocephalids from the Permian of Greenland. Similar to other eugeneodontids such as ''Edestus'' and ''Helicoprion'', it was best known for its extremely bizarre tooth morphology compared to other species of sharks and their closest relatives, the chimaeras. Compared to other members of the Helicoprionidae (teeth of Agassiz), its "tooth whorls" were found to be sharper, more compact, and in better condition than other sharks of the time, and refrained from growing to extremely unwieldy forms that would raise questions about its ability to feed properly. The genus contains one species, ''Sarcoprion edax'' ("gluttonous flesh saw"), found in Permian-aged marine strata of ''Meddelelser om Grønland''. Description ''Sarcoprion'' had a jaw and mouth structure which allowed it to be more hydrodynamic, reducing the size and shape of the tooth whorl and increasing the size of the rostrum. ''Sarc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicoprion
''Helicoprion'' is an extinct genus of shark-like eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown. Fossils of ''Helicoprion'' are known from a 20 million year timespan during the Permian period from the Artinskian stage of the Cisuralian (Early Permian) to the Roadian stage of the Guadalupian (Middle Permian). The closest living relatives of ''Helicoprion'' (and other eugeneodonts) are the chimaeras, though their relationship is very distant. The unusual tooth arrangement is thought to have been an adaption for feeding on soft bodied prey, and may have functioned as a deshelling mechanism for hard bodied cephalopods such as nautiloids and ammonoids. In 2013, systematic revision of ''Helicoprion'' via morphometric analysis of the tooth whorls found only ''H. davisii, H. bessonowi'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicoprionidae
The Helicoprionidae, also known as the Agassizodontidae are an extinct, poorly known family of bizarre holocephalids within the poorly understood order Eugeneodontida. Members of the Helicoprionidae possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials. The closest living relatives of the Helicoprionidae and all other eugeneodontids are the ratfishes. The anatomy of the tooth-whorl differed amongst genus and species, some possessing complete spirals (such as those of ''Helicoprion ''Helicoprion'' is an extinct genus of shark-like eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extin ...''), others possessing halved spirals (seen in '' Parahelicoprion''), and some with wedged half-spirals (seen in '' Sarcoprion''). Each tooth-whorl is thought to be adapted to a different type of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agassizodontidae
The Helicoprionidae, also known as the Agassizodontidae are an extinct, poorly known family of bizarre holocephalids within the poorly understood order Eugeneodontida. Members of the Helicoprionidae possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials. The closest living relatives of the Helicoprionidae and all other eugeneodontids are the ratfishes. The anatomy of the tooth-whorl differed amongst genus and species, some possessing complete spirals (such as those of ''Helicoprion''), others possessing halved spirals (seen in ''Parahelicoprion ''Parahelicoprion'' is an extinct genus of shark-like eugeneodontid holocephalids from the Permian of the Ural Mountains (Russia) and Copacabana Formation, Bolivia. The genus name, from "nearly coiled saw" in Greek, directly refers to ''Helico ...''), and some with wedged half-spirals (seen in '' Sarcoprion''). Each tooth-whorl is thought to be adapted to a different type of pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugeneodontid
The Eugeneodontida is an extinct and poorly known order of cartilaginous fishes. They possessed "tooth-whorls" on the symphysis of either the lower or both jaws and pectoral fins supported by long radials. They probably lacked pelvic fins and anal fins. The palatoquadrate was either fused to the skull or reduced. Now determined to be within the Holocephali, their closest living relatives are ratfish. The eugeneodonts are named after paleontologist Eugene S. Richardson, Jr. The Eugeneodontida disappeared in the Early Triassic. Members of the Eugeneodontida are further classified into different families, the most well-preserved members that have been discovered are commonly placed within the families Helicoprionidae ("spiral saws"), and Edestidae ("those which devour"), the former containing the genera ''Helicoprion'', '' Sarcoprion'', and ''Parahelicoprion'', and the latter containing the genera ''Edestus'', ''Lestrodus'', and '' Metaxyacanthus''. All eugeneodonts are thought to h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Cartilaginous Fish Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian Fish Of North America
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their amphibian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanislav Drobyshevsky
Stanislav Vladimirovich Drobyshevsky (born 2 July 1978, in Chita) is a Russian anthropologist and science popularizer. He is a Candidate of Sciences and works at the Anthropology department of the Faculty of Biology of Moscow State University. He is a scientific editor of the popular science portal '' Antropogenez.ru''. His body of work includes monographs, university textbooks, and popular science books. He is a vlogger and YouTuber. He also frequently appears in other Russian popular science channels. Education He studied at the MSU Faculty of Biology as an undergraduate in 1995-2000, and as a graduate student in 2000-2004. After getting a Candidate's degree in 2004, he has been working at the Anthropology Department of that faculty. He created university courses in human evolution, anthropology, archaeology, and race science. Science communication Non-missing link In addition to his editorial activities, Drobyshevsky is actively working on his own project ''Non-m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eksmo
Eksmo (russian: Эксмо) is one of the largest publishing houses in Russia. Eksmo and AST (which it later acquired in 2012) together publish approximately 30% of all Russian books. Established in 1991 as a small book-selling company, Eksmo gradually developed into a major player in the Russian market, discovering and developing detective-novel authors such as Darya Dontsova and Alexandra Marinina, as well as publishing works by Tatyana Tolstaya, Lyudmila Ulitskaya, Tatiana Vedenska Tatiana Vedenska (russian: link=, Татьяна Евгеньевна Веденская; born 15 July 1976) is a widely known Russian writer and novelist. Biography Tatiana was born in Moscow into the family of an engineer. Her great grandfat ..., and Viktor Pelevin. Eksmo has become especially successful as a publisher of Russian science fiction and fantasy, with writers like Sergey Lukyanenko, Yuri Nikitin (author), Yuri Nikitin, Vasily Golovachev, Nick Perumov, Vera Kamsha, Vadim Panov and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mako Shark
''Isurus'' is a genus of mackerel sharks in the family Lamnidae, commonly known as the mako sharks. Description The two living species are the common shortfin mako shark (''I. oxyrinchus'') and the rare longfin mako shark (''I. paucus''). They range in length from , and have an approximate maximum weight of . They both have a distinctive blue-gray color scheme common among mackerel sharks. Several extinct species are known from fossils found in sediments from the Cretaceous to the Quaternary (age range: 99.7 to 0.781 million years ago). The family Lamnidae also includes the great white shark and the porbeagle. Mako sharks are capable of swimming at speeds up to . The great white shark is also closely related to an ancient mako shark species, ''Isurus hastalis''. However, fossil evidence suggests ''I. hastalis'', like the great white shark, also belonged to the genus ''Carcharodon''. Species The genus contains these species: * ''Isurus oxyrinchus'' (Rafinesque, 1810) (shortfin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he received a PhD at Erlangen and a medical degree in Munich. After studying with Georges Cuvier and Alexander von Humboldt in Paris, Agassiz was appointed professor of natural history at the University of Neuchâtel. He emigrated to the United States in 1847 after visiting Harvard University. He went on to become professor of zoology and geology at Harvard, to head its Lawrence Scientific School, and to found its Museum of Comparative Zoology. Agassiz is known for observational data gathering and analysis. He made institutional and scientific contributions to zoology, geology, and related areas, including multivolume research books running to thousands of pages. He is particularly known for his contributions to ichthyological classification, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimaera
Chimaeras are cartilaginous fish in the order Chimaeriformes , known informally as ghost sharks, rat fish, spookfish, or rabbit fish; the last three names are not to be confused with rattails, Opisthoproctidae, or Siganidae, respectively. At one time a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks and rays, though their last common ancestor with them lived nearly 400 million years ago. Today, they are largely confined to deep water. Description and habits Chimaeras live in temperate ocean floors down to deep, with few occurring at depths shallower than . Exceptions include the members of the genus ''Callorhinchus'', the rabbit fish and the spotted ratfish, which locally or periodically can be found at shallower depths. Consequently, these are also among the few species from the chimaera order kept in public aquaria. They live in all the oceans except for the Arctic and Antarctic oceans. They have elongated, soft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
