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Ischyrhiza
''Ischyrhiza'' is an extinct genus of sclerorhynchoid ray from the Late Cretaceous and Early Paleogene. It had a large, toothed rostrum closely resembling that of a modern-day sawfish. Despite formerly being classified within a family of extinct sawfish-like rays known as Sclerorhynchidae, phylogenetic analyses indicate that ''Ischyrhiza, Schizorhiza'', and '' Onchopristis'' form a distinct clade that groups closer with the extant family Rajidae, which contains the true skates, possibly rendering the suborder Sclerorhynchoidei paraphyletic. Fossils of the genus have been found in Canada, the United States, the Aguja Formation of Mexico, the Bissekty Formation of Uzbekistan, the Tamayama Formation of Japan, the Dukamaje Formation of Niger, the El Molino Formation of Bolivia, the Quiriquina Formation of Chile, and the Chota Formation The Chota Formation is an Early Campanian to Late Eocene geologic formation of the Cajamarca and western Amazonas Region in northern Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onchopristis
''Onchopristis'' is an extinct genus of sclerorhynchoid from the Cretaceous of North Africa, Europe, and North America. Its name is derived from the Ancient Greek ''ónkos'' ( ὄγκος, 'barb') and ''prístis'' ( πρίστις, 'saw' or 'sawfish'). It contains two valid species, ''O. numida'' and ''O. dunklei''. ''Onchopristis'' first appeared in the Barremian and its latest occurrence dates to the Campanian, making it one of the oldest and longest-lived sclerorhynchoid genera. Description Specimens of ''O. numida'', IPUW 353500 and IGR 2818, suggest a length estimate of and , respectively; such individuals would have weighed . Like other sclerorhynchoids, it had a long rostrum with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved and its closest living relatives are actually skates. Isolated rostral denticles are the most common fossils of ''Onchopristis'', but rostra, chondrocrania, jaws, oral teeth, vertebrae, and dermal den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclerorhynchoidei
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name for sclerorhynchoids. The suborder contains five named families: Ganopristidae, Ischyrhizidae, Onchopristidae, Ptychotrygonidae, and Schizorhizidae. Several genera (see below) are not currently placed in any of these families. Sclerorhynchoids first appeared in the Barremian and went extinct during the Cretaceous–Paleogene extinction event, with former Paleocene occurrences being misidentifications or reworked specimens. Phylogeny Below is a cladogram of Sclerorhynchoidei, with the topology based on Villalobos-Segura ''et al.'' (2021b) and the family taxonomy based on Greenfield (2021). Other genera *†''Agaleorhynchus'' *†''Ankistrorhynchus'' *†''Arc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quiriquina Formation
The Quiriquina Formation is a geological formation in Chile whose strata date back to the 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'', .... 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. . The glauconite, glauconitic sandstones and conglomerate (geology), conglomerates of the formation were deposited in a marine depositional environment, environment. Vertebrate paleofauna * ''Aristonectes, Aristonectes quiriquinensis'' * ''Australobaena, Australobaena chilensis'' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Molino Formation
The El Molino Formation is a Maastrichtian geologic formation pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine environment. The formation has provided fossils of '' Dolichochampsa minima'',Buffetaut, 1987 and ichnofossils of Ankylosauria indet., Ornithopoda indet., Theropoda indet. and Titanosauridae indet.Lockley et al., 2002, p.389 The tracksite of Cal Orcko is the best known example of the ichnofossil locations of the formation. The ichnofossil of '' Ligabueichnum bolivianum'' may be attributed to an ankylosaur.Leonardi, 1994, p.39 The fossil fish species ''Dasyatis molinoensis'' is named after the formation. Fossil content Other fossils retrieved from the formation are: [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dukamaje Formation
The Dukamaje Formation is a geological formation in Niger whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604-605. . A wealth of Mosasaur fossils have also been recovered from this formation, particularly from the area around Mt. Igdaman. Fossil content ;Other reptiles * '' Sokotosuchus ianwilsoni'' * '' Palaeophis sp.'' * '' Podocnemis sp.'' * '' Trematochampsa taqueti'' * '' Libycosuchus sp.'' ;Fishes * '' Asteracanthus aegyptiacus'' at |
Schizorhiza
''Schizorhiza'' is a fossil genus of cartilaginous fish, containing a single accepted species ''Schizorhiza stromeri''. Its fossils are found in rocks dating from the Campanian and Maastrichtian stages; it thus lived between about and million years ago. Like other sawfish-like rays from the Mesozoic, it probably did not survive the Cretaceous–Paleogene extinction event; there are a few remains from the Paleogene but these seem to have been reworked from Late Cretaceous deposits. (2002): ''Schizorhiza'': a unique sawfish paradigm from the Difunta Group, Coahuila, Mexico. ''Revista Mexicana de Ciencias Geológicas'' 19(1): 16-24 nglish with Spanish abstractbr>PDF fulltext/ref> Taxonomy Due to its unique rostral teeth, ''Schizorhiza'' is placed in the monotypic subfamily Schizorhizinae. Despite formerly being classified within a family of extinct sawfish-like rays known as Sclerorhynchidae, phylogenetic analyses indicate that ''Ischyrhiza, Schizorhiza'', and ''Onchopristis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bissekty Formation
The Bissekty Formation (sometimes referred to as Bissekt) is a geologic formation and Lagerstätte which crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period. Laid down in the mid to late Turonian, it is dated to about 92 to 90 Ma (million years ago). Description The lithology of the sediment largely consists of cross bedded sandstones with interbeds of massive sandstone, well cemented intraformational conglomerate, siltstones and mudstones. Most of the fossils are found as clasts within the conglomerates. Fossil content The Bissekty Formation is characterised by a mix of marine, brackish, freshwater, and terrestrial animal fossils. This stands in contrast the strictly marine fossils found in the underlying Dzheirantui Formation, and indicates that the Bissekty was formed during the regression of a saltwater sea. The coastline expanded inland again in the upper portion of the Bissekty, represented by a proportional increase of fully aquat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aguja Formation
The Aguja Formation is a geological formation in North America, exposed in Texas, United States and Chihuahua and Coahuila in Mexico, 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, "Dinosaur distribution (Late Cretaceous, North America).", pp.574-588 Fossil palms have also been unearthed here. Age The ages of the Aguja Formation and its primary fossil-bearing unit, the Upper Shale, are not well understood. Due to the presence of the ammonite ''Baculites mclearni'', which only occurs from 80.67 - 80.21 Ma, in the underlying Rattlesnake Mountain Sandstone and the Terlingua Creek Sandstone, it is likely that the Upper Shale was younger than 80.2 Ma. A radiometric date of 76.9 Ma was recovered in the Upper Shale, making it likely the formation wasn't younger than 76.9 Ma. The contact with the overlying Javelina Formation has been estimated at about 70 Ma agoWoodward, H. N. (2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Cartilaginous Fish
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
