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Meiolaniformes
Meiolaniformes is an extinct clade of stem-group turtles, defined as all taxa more closely related to ''Meiolania'' than to Cryptodira and Pleurodira. It is known from the Early Cretaceous to the Holocene of Australia, Oceania and South America. Some Eurasian taxa have been suggested to be part of the group, but this is disputed. The oldest member of Meiolaniformes is Australian Early Cretaceous '' Otwayemys''. Taxonomy The clade as currently defined contains the following taxa: * †''Chubutemys'' Gaffney et al. 2007 - Aptian, Cerro Barcino Formation, Argentina * †'' Otwayemys'' Gaffney et al. 1998 - Aptian, Eumeralla Formation, Australia * †''Patagoniaemys'' Sterli and de la Fuente 2011 Upper Campanian-Lower Maastrichtian, La Colonia Formation, Argentina * †'' Peligrochelys'' Sterli and de la Fuente 2011 Danian, Salamanca Formation, Argentina * †'' Trapalcochelys'' Sterli et al. 2013 Upper Campanian, Allen Formation, Argentina * †Meiolaniidae Lydekker 1887, Eocene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiolaniidae
Meiolaniidae is an extinct family of large, probably herbivorous stem-group turtles with heavily armored heads and tails known from South America and Australasia. Though once believed to be cryptodires, they are not closely related to any living species of turtle, and lie outside crown group Testudines, having diverged from them around the Middle Jurassic. They are best known from the last surviving genus, ''Meiolania'', which lived in the rain forests of Australia from the Miocene until the Pleistocene, and insular species that lived on Lord Howe Island and New Caledonia during the Pleistocene and possibly the Holocene for the latter. Meiolaniids are part of the broader grouping of Meiolaniformes, which contains more primitive turtles species lacking the distinctive morphology of meiolaniids, known from the Early Cretaceous-Paleocene of South America and Australia. A similar form is also known from the Miocene Saint Bathans fauna of New Zealand. Meiolaniids reached total lengt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salamanca Formation
The Salamanca Formation is a geologic formation in the Golfo San Jorge Basin of central Patagonia that yields well-preserved, well-dated fossils from the early Paleocene. Studies of these fossils are providing new data on plant and animal diversity following the Cretaceous–Paleogene extinction event, end-Cretaceous extinction event. Material was copied from this source, which is available under a creativecommons:by/4.0/, Creative Commons Attribution 4.0 International License The Salamanca Formation crops out in the San Jorge Basin in southern Chubut and northern Santa Cruz provinces, Argentina, overlying the Cretaceous Chubut Group and is part of the Paleocene and Eocene Río Chico Group. The formation yields abundant plant remains as well as fossils of Invertebrate, invertebrates, marine macrofaunas, Reptile, reptiles, and Mammal, mammals. The formation consists primarily of estuarine to shallow marine deposits. Palynological analysis of the Salamanca Formation shows low flora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiolania
''Meiolania'' ("small roamer") is an extinct genus of meiolaniid stem-turtle native to Australasia from the Middle Miocene to Late Pleistocene and possibly Holocene. It is best known from fossils found on Lord Howe Island, though fossils are known from mainland Australia, New Caledonia, and possibly Vanuatu and Fiji. Taxonomy The genus was erected in 1886 based on remains found on Lord Howe Island, which Richard Owen assigned to the two species ''M. platyceps'' and ''M. minor'' (now a synonym of the former). These were the first good meiolaniid remains, and were used to show that the first known remains of a related animal, a species from Queensland now known as '' Ninjemys oweni'' (which was assigned to ''Meiolania'' until 1992), did not belong to lizards as initially thought, but to turtles. Woodward sank ''Niolamia argentina'' into ''Meiolania'', but this was not accepted by later authors. The species of the genus may be summarized as In New Caledonia, ''M. mackayi'' was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chubutemys
''Chubutemys'' was an extinct genus of meiolaniform turtle. It lived during the Early Cretaceous of Argentina, around the Albian-Aptian border, within the Puesto La Paloma Member of the Cerro Barcino Formation. It is known from most of the skeleton and carapace, and part of the skull. Description A skeleton, including most of the skull, is known for ''Chubutemys''. As the skull was found in the same quarry as the postcranial skeleton, it was decided to be likely to be from the same individual. The shell of the specimen is remarkably thin. Classification ''Chubutemys'' is a turtle that is relatively easy to classify. Among related genera, Sterli ''et al.'' found ''Patagoniaemys'' to be the most unstable genus. The cladogram below shows the relationships of ''Chubutemys'', and three possible placements of ''Patagoniaemys'': Paleoecology ''Chubutemys'' is from the Cerro Barcino Formation. A locality of many turtles, nicknamed "Turtle Town", located within the Puesto La Paloma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eumeralla Formation
The Eumeralla Formation is a geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is Aptian to Albian in age. Dinosaur remains are among the fossils that have been recovered from the formation, particularly from the Dinosaur Cove localityWeishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Australasia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 573-574. . It is partially equivalent to the Wonthaggi Formation. Geology The Eumeralla Formation was deposited within an extensional rift valley formed between Australia and Antarctica. The lithology primarily consists of fluvially deposited siliciclastics derived from volcanic material. The strata of the Eumeralla Formation are folded as a result of northwest–southeast crustal compression during the Neogene, which also reactivated some Cretaceous aged normal faults. Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patagoniaemys
''Patagoniaemys'' is an extinct genus of stem turtle which existed in central Patagonia, Chubut Province, Argentina during the late Cretaceous epoch (Campanian to Maastrichtian age). It is known from skull fragments and several postcranial elements including a nearly complete vertebral column recovered from the La Colonia Formation. It was first named by Juliana Sterli and Marcelo S. de la Fuente in 2011 File:2011 Events Collage.png, From top left, clockwise: a protester partaking in Occupy Wall Street heralds the beginning of the Occupy movement; protests against Libyan dictator Muammar Gaddafi, who was killed that October; a young man celebrate ..., and the type species is ''Patagoniaemys gasparinae''. References Prehistoric turtle genera Late Cretaceous turtles Campanian life Maastrichtian life Prehistoric turtles of South America Cretaceous Argentina Fossils of Argentina Cañadón Asfalto Basin Fossil taxa described in 2011 Meiolaniformes {{paleo-turtl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic column wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition The Maastrichtian was introduced into scientific literature by Belgian geologist André Hubert Dumont in 1849, after studying rock strata of the Chalk Group c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Colonia Formation
The La Colonia Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., 2004, pp.600-604 Originally thought to be Campanian (c.73-72 million years ago) in age or earlier, studies of underlying formations have made a Maastrichtian (70–66 million years ago) age more likely.Rauhut, 2003 It is divided up into three distinct facies, the first is up to thick and consists of conglomerate, the second is by far the thickest at over , consists of siltstone and claystone, with interbeds of claystone/shale and sandstone, the third is less than thick and consists of clay, and probably represents a nearshore marine environment.Gasparini et al., 2015 Flora The paleoflora was known for its aquatic components, ''Paleoazolla'' and ''Regnellidium''. However, recent paleobotanical discoveries at the Cañadón del Irupé locality have revealed the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danian
The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretaceous–Paleogene extinction event . The age ended , being followed by the Selandian. Stratigraphic definitions The Danian was introduced in scientific literature by German-Swiss geologist Pierre Jean Édouard Desor in 1847 following a study of fossils found in France and Denmark.Danien He identified this stage in deposits from |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allen Formation
The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian.Salgado et al., 2007 Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. . Description The stratotype of the formation was defined by Uliana and Dellapé in 1981 in the eastern area of the Bajo de Añelo, where the relation between base and top is clearly exposed. The deposits are mostly clastic, interbedded with banks of limestone and layers of anhydrite, which were defined continental and shallow marine facies associated with semiarid conditions.Armas & Sánchez, 2015, p.101 The interpreted sedimentary paleoenvironments range from purely continental such as ephemer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
