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Gondwanascorpio Emzantsiensis
''Gondwanascorpio emzantsiensis'' is an extinct Gondwanan scorpion that lived 360 million years ago in the Devonian. Its fossil remains, clearly showing pincer and sting, were discovered in rocks of the Witteberg Group near Grahamstown in South Africa. At present, this scorpion is the oldest known land-dwelling animal from Gondwana, which in Devonian times was separated from Laurasia by a deep ocean. At the time, the fossil site was only 15° from the South Pole, but rather than arctic-like tundra, the region was probably wooded, providing ample insect life for food. Previously, only two scorpion species were known from the late Devonian – '' Hubeiscorpio gracilitarsus'' from China and '' Petaloscorpio bureaui'' from Canada. The species was described by Robert Gess of Wits University in the journal ''African Invertebrates''. The specific epithet derives from ', the isiXhosa word for "south", sometimes used for South Africa. The shale containing the fossil was discovered as far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telson
The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment (biology), segment of the arthropod body, or an additional division that is not a true segment on account of not arising in the embryo from teloblast areas as other segments. It never carries any appendages, but a forked "tail" called the caudal furca may be present. The shape and composition of the telson differs between arthropod groups. Crustaceans In lobsters, Caridea, shrimp and other Decapoda, decapods, the telson, along with the uropods, forms the tail fan. This is used as a paddle in the caridoid escape reaction ("lobstering"), whereby an alarmed animal rapidly flexes its tail, causing it to dart backwards. Krill can reach speeds of over 60 cm per second by this means. The Induction period, trigger time to optical stimulus (physiology), stimulus is, in spite of the low temperatures, only 55 milliseconds. In th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Document Format
Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it. PDF has its roots in "The Camelot Project" initiated by Adobe co-founder John Warnock in 1991. PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020. PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video content), three-dimensional objects using U3D or PRC, and various other data formats. The PDF specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Scorpion Genera
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins 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 years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serenichthys Kowiensis
''Serenichthys kowiensis'' is a fossil species of coelacanth described in 2015 from near Grahamstown in South Africa. Some 30 complete specimens of this new species were found in the black shale lagerstätte on Waterloo Farm, preserved by the mud of an ancient estuary dating back to the Famennian stage of the Late Devonian some 360 million years ago. In an article published in the Zoological Journal of the Linnean Society and jointly authored by paleontologists Michael Coates of the University of Chicago and Robert Gess from the University of the Witwatersrand, the find is described as the earliest coelacanth to be discovered from Africa. Gess first identified coelacanth remains from this locality in the 1990s, but these were poorly preserved and unsuitable for formal description. Subsequent work produced many more specimens, some preserved in fine detail. All specimens of ''Serenichthys kowiensis'' have been added to the palaeontological collection of the Albany Museum in Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are a group of Agnatha, jawless fish comprising the order (biology), order Petromyzontiformes , sole order in the Class (biology), class Petromyzontida. The adult lamprey is characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. "Lamprey" is sometimes seen for the plural form. About 38 extant species of lampreys are known, with around seven known extinct species. They are classified in three families—two small families in the Southern Hemisphere (Geotriidae, Mordaciidae) and one large family in the Northern Hemisphere (Petromyzontidae). Genetic evidence suggests that lampreys are more closely related to hagfish, the only other living group of jawless fish, than they are to jawed vertebrates, forming the superclass Cyclostomi. The oldest fossils of stem-group lampreys are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priscomyzon Riniensis
''Priscomyzon riniensis'' is an extinct lamprey that lived some 360 million years ago during the Famennian (Late Devonian) in a marine or estuarine environment in South Africa. This small agnathan is anatomically similar to the Mazon Creek lampreys, but is some 35 million years older. Its key developments included the first known large oral disc, circumoral teeth and a branchial basket. Context Though common and diverse during the Silurian and Devonian, jawless fish are today represented only by lampreys and hagfish, both groups being quite specialized. Lampreys have seven gill pouches (whereas jawed fish have only five), no paired fins, and a rudimentary skeleton of cartilage. They also have a sucker disc of cartilage surrounded by a soft lip and a central small mouth set about with simple hooked teeth. They attach to the bodies of other vertebrates by suction, securing their grip with the hooked teeth, after which a rasped tongue scrapes a hole providing access to the hos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterloo Farm Lagerstätte
The Waterloo Farm lagerstätte is a Famennian lagerstätte in South Africa that constitutes the only known record of a near-polar Devonian coastal ecosystem. History and discovery The Waterloo Farm Lagerstätte is an approximately 360 million year old Famennian (latest Devonian) fossil-rich locality of the Witpoort Formation (Witteberg Group, Cape Supergroup) in Makhanda, Eastern Cape, Makhanda (former Grahamstown) within the Eastern Cape, Eastern Cape Province, South Africa. Before its discovery very little was known of life during the Famennian (see Late Devonian extinction) in what is now southern Africa. This is largely due to the fact that fossils in the Witpoort Formation generally occur in black anaerobically deposited metashale that rapidly degrades near surface and is therefore rarely seen in natural outcrop. As is the case with many other scientific discoveries, the discovery of Waterloo Farm was accidental. Uprisings against the apartheid system in South Africa had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeopteris
''Archaeopteris'' is an extinct genus of progymnosperm tree with fern-like leaves. A useful List of index fossils, index fossil, this tree is found in Stratum, strata dating from the Upper Devonian to Lower Carboniferous (), the oldest fossils being 385 million years old, and had global distribution. Until the 2007 discovery of ''Wattieza'', many scientists considered ''Archaeopteris'' to be the earliest known tree. Bearing buds, reinforced branch joints, and branched trunks similar to today's Woody plant, woody plants, it is more reminiscent of modern seed-bearing trees than other spore-bearing Taxon, taxa. It combines characteristics of woody trees and herbaceous ferns, and belongs to the progymnosperms, a group of extinct plants more closely related to Seed plant, seed plants than to ferns, but unlike seed plants, reproducing using spores like ferns. Taxonomy John William Dawson described the genus in 1871. The name derives from the ancient Greek (''archaīos'', "ancient" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Fossil
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology'', 8th ed., Oxford University Press, 2019. The primary objective of biostratigraphy is ''correlation'', demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at a different section. Fossils within these strata are useful because sediments of the same age can look completely different, due to local variations in the sedimentary environment. For example, one section might have been made up of clays and marls, while another has more chalky limestones. However, if the fossil species recorded are similar, the two sediments are likely to have been laid down around the same time. Ideally these fossils are used to help identify biozones, as they make up the basic biostratigraphy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Period
The Carboniferous ( ) is a geologic period and system of the Paleozoic era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian and the later Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the period during which both terrestrial animal and land plant life was well established. Stegocephalia (four-limbed vertebrates including true tetrapods), whose forerunners (tetrapodomo ... [...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] |
Pangaea
Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous period approximately 335 million years ago, and began to break apart about 200 million years ago, at the end of the Triassic and beginning of the Jurassic. Pangaea was C-shaped, with the bulk of its mass stretching between Earth's northern and southern polar regions and surrounded by the superocean Panthalassa and the Paleo-Tethys and subsequent Tethys Oceans. Pangaea is the most recent supercontinent to have existed and was the first to be reconstructed by geologists. Origin of the concept The name "Pangaea" is derived from Ancient Greek ''pan'' (, "all, entire, whole") and '' Gaia'' or Gaea (, " Mother Earth, land"). The first to suggest that the continents were once joined and later separated may have been Abraham Ortelius in 1596. The concept that the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
