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Megachasma Applegatei
''Megachasma applegatei'' is an extinct species of megamouth shark from the Oligocene to early Miocene (28-23 Mya) of the Western United States. The type fossil was discovered in the San Joaquin Valley The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven c ... in 1973, but only described in 2014, when the species was named after its discoverer, Shelton Applegate. Description ''Magachasma applegatei'' was described from a single tooth. Based on comparison with the teeth of the recent species (''Megachasma pelagios''), it was approximately 6 m long and, like modern megamouth sharks, probably fed on fish and small planktonic invertebrates both in deep and shallow water habitats. Its teeth had shorter crowns and a pair of side cusplets. References Megachasmidae Prehistoric sharks Fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megamouth Shark
The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant taxon, extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its discovery in 1976, fewer than 100 specimens have been observed or caught. Like the other two Planktivore, planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae. Description The appearance of the megamouth is distinctive, but little else is known about it. It has a brownish-black colour on top, is white underneath, and has an asymmetrical tail with a long upper lobe, similar to that of the thresher shark. The i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Joaquin Valley
The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven counties of Northern and one of Southern California, including, in the north, all of San Joaquin and Kings counties, most of Stanislaus, Merced, and Fresno counties, and parts of Madera and Tulare counties, along with a majority of Kern County, in Southern California. Although the valley is predominantly rural, it has densely populated urban centers: Fresno, Bakersfield, Stockton, Modesto, Tulare, Visalia, Hanford, and Merced. The first European to enter the valley was Pedro Fages in 1772. The San Joaquin Valley was originally inhabited by the Yokuts and Miwok peoples. The Tejon Indian Tribe of California is a federally recognized tribe of Kitanemuk, Yokuts, and Chumash indigenous people of California. Their ancestral homeland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megachasmidae
''Megachasma'' is a genus of sharks. It is usually considered to be the sole genus in the distinct family Megachasmidae, though suggestion has been made that it may belong in the family Cetorhinidae, of which the basking shark is currently the sole extant member. ''Megachasma'' is known from a single living species, ''Megachasma pelagios''. In addition to the living ''M. pelagios'', however, two extinct megamouth species – the Priabonian '' M. alisonae''Shimada, Kenshu, and David J. Ward. "The oldest fossil record of the megamouth shark from the late Eocene of Denmark, and comments on the enigmatic megachasmid origin./ref> and the Oligocene–Miocene '' M. applegatei'' – have also recently been proposed on the basis of fossilized tooth remains. An early ancestor of the recent species ''Megachasma pelagios'' was reported from the early Miocene (Burdigalian) of Belgium. However, the Cretaceous-aged ''M. comanchensis'' has been recently reclassified as an odontas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Sharks
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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 2014
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 absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
