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2019 In Paleoichthyology
This list of fossil fishes described in 2019 is a list of new taxa of Agnatha, jawless vertebrates, placoderms, Acanthodii, acanthodians, fossil Chondrichthyes, cartilaginous fishes, Osteichthyes, bony fishes, and other fishes of every kind that were binomial nomenclature, described during the year 2019, as well as other significant discoveries and events related to paleoichthyology that occurred in 2019. New taxa Jawless vertebrates Placoderms Acanthodians Cartilaginous fishes Ray-finned fishes Lobe-finned fishes Other fishes General research * Revision of Early Devonian Psammosteidae, psammosteids described by Beverly Halstead from the so-called "Placoderm Sandstone" (Świętokrzyskie Mountains, Poland) is published by Dec (2019). * A study on the locomotion of psammosteids, focusing on the influence of the shape of the psammosteid body form on hydrodynamic performance, is published by Dec (2019). * A study on the anatomy of dermal plates of ''Astraspis'' is publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the abs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galeaspida
Galeaspida (from Latin, 'Helmet shields') is an extinct taxon of jawless marine and freshwater fish. The name is derived from ''galea'', the Latin word for ''helmet'', and refers to their massive bone shield on the head. Galeaspida lived in shallow, fresh water and marine environments during the Silurian and Devonian times (430 to 370 million years ago) in what is now Southern China, Tibet and Vietnam. Superficially, their morphology appears more similar to that of Heterostraci than Osteostraci, there being currently no evidence that the galeaspids had paired fins. A galeaspid ''Tujiaaspis vividus'' from the Silurian period of China was described in 2022 as having a precursor condition to the form of paired fins seen in Osteostraci and gnathostomes. Earlier than this, Galeaspida were already in fact regarded as being more closely related to Osteostraci, based on the closer similarity of the morphology of the braincase. Morphology The defining characteristic of all galeaspids w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hagfish
Hagfish, of the class Myxini (also known as Hyperotreti) and order Myxiniformes , are eel-shaped, slime-producing marine fish (occasionally called slime eels). They are the only known living animals that have a skull but no vertebral column, although hagfish do have rudimentary vertebrae. Along with lampreys, hagfish are jawless; the two form the sister group to jawed vertebrates, and living hagfish remain similar to hagfish from around 300 million years ago. The classification of hagfish had been controversial. The issue was whether the hagfish was a degenerate type of vertebrate-fish that through evolution had lost its vertebrae (the original scheme) and was most closely related to lampreys, or whether hagfish represent a stage that precedes the evolution of the vertebral column (the alternative scheme) as is the case with lancelets. Recent DNA evidence has supported the original scheme. The original scheme groups hagfish and lampreys together as cyclostomes (or histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Lebanon
The paleontological sites of Lebanon contain deposits of well preserved fossils and include some species found nowhere else. Notable among these is the Lebanese lagerstätten of the Late Cretaceous age, which contain a well-preserved variety of different fossils. Some fossils date back to the Jurassic period, and younger fossils of mammals from a different site belong to the Miocene through the Pleistocene. History The earliest known account of Lebanese fossils is attributed to Herodotus. The existence of fossil fishes in the Lebanon is referred to by Jean de Joinville. In his ''Histoire de Saint Louis'' he wrote that during the sojourn of King Louis IX of France at Sidon in 1253, just before his return home from the Seventh Crusade, a stone was brought him, European scientists became interested in Lebanese fossils in the 19th century. Locations and fossils There are three major fossil locations in Lebanon: Sahel Alma, Hajula and Hakel. Hajula and Hakel are each abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hjoula
Hjoula ( ar, حجولا) is a municipality in the Byblos District of Keserwan-Jbeil Governorate, Lebanon. It is 70 kilometers north of Beirut. Hjoula has an elevation of between 920 and 1,100 meters above sea level. Hjoula has a total land area of 528 hectares. The village of Hjoula is known for its fertile soil and its woods, as well as Early Cretaceous fossils. Etymology The word is an Aramaic one, however the meaning is uncertain. Most historians and linguists suggest it means "Oval" due to its oval shape, while some others speculate it comes from the Syriac root "G-l-a" and subsequently to the word "Guola" which supposedly means "The place of the wandering salesman". History Many old relics and monuments were found in Hjoula. There was found a Phoenician inscription in "Jarabta". A Roman statue that represented a shepherd and his sheep was also found beside the lake, and was dated to the era of emperor Tiberius c. 20 CE; along small sets of coins that were written in Kufic wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelolepidae
Coelolepidae is an extinct family of thelodont vertebrate agnatha Agnatha (, Ancient Greek 'without jaws') is an infraphylum of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present ( cyclostomes) and extinct (conodonts and ostracoderms) species. Among recent animals, cyclos ...ns that lived during the Silurian.Pander, C. H., 1856. Monographie der fossilen Fische des silurischen Systems der russisch-baltischen Gouvernments. Buchdruckerei der Kaiserlichen Akademie der Wissenschaften, St. Petersburg, 91 pp. References External links * Thelodonti Prehistoric jawless fish families Silurian jawless fish {{Silurian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thelodonti
Thelodonti (from Greek: "feeble teeth")Maisey, John G., Craig Chesek, and David Miller. Discovering fossil fishes. New York: Holt, 1996. is a class of extinct jawless fishes with distinctive scales instead of large plates of armor. There is much debate over whether the group of Palaeozoic fish known as the Thelodonti (formerly coelolepids) represent a monophyletic grouping, or disparate stem groups to the major lines of jawless and jawed fish. Thelodonts are united in possession of " thelodont scales". This defining character is not necessarily a result of shared ancestry, as it may have been evolved independently by different groups. Thus the thelodonts are generally thought to represent a polyphyletic group, although there is no firm agreement on this point. On the basis that they are monophyletic, they are reconstructed as being ancestrally marine and invading freshwater on multiple occasions. "Thelodonts" were morphologically very similar, and probably closely relate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xitun Formation
The Xitun Formation is a palaeontological formation which is named after Xitun village in Qujing, a location in South China. This formation includes many remains of fossilized fish and plants of the Early Devonian period (Late Lochkovian). It was originally referred to as the Xitun Member of the Cuifengshan Formation (now the Cuifengshan Group). Fossil content Vertebrates Acanthodians Actinopterygians Chondrichthyes Jawless fish Placoderms Sarcopterygians Plants See also * List of fossil sites This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of t ...— ''(with link directory)'' References Geologic formations of China Devonian System of Asia Devonian China Devonian northern paleotropical deposits Paleontology in China {{China-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xishancun Formation
The Xishancun Formation is a geological formation located at Qujing, Yunnan, South China. Xishancun Formation has remains of petalichthyid and galeaspid fish and it represents the Early Devonian period (Early Lochkovian) of China. See also * List of fossil sites This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of t ... ''(with link directory)'' Geologic formations of China Devonian System of Asia Devonian China Devonian northern paleotropical deposits Paleontology in Yunnan {{China-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
