| Chilenosuchus Temporal range: Late Triassic ~ | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Pseudosuchia |
| Order: | † Aetosauria |
| Family: | † Stagonolepididae |
| Genus: | † Chilenosuchus Casamiquela 1980 |
| Species | |
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Chilenosuchus is an extinct genus of aetosaur. Fossils have been found in the El Bordo Formation, in the Antofagasta Region in northern Chile. [1]
The presence of Chilenosuchus in the beds that it was found in conflicts with the inferred age of the strata. Fossil plants and invertebrates suggest that it dates back to the late Carboniferous or Early Permian, [2] yet Chilenosuchus is an aetosaur, and the first aetosaurs appeared in the Late Triassic. Poor-quality photographs of the original specimen and an apparent lack of substantial material could not allow for definite classification of the specimen, so there was initially much controversy as to whether or not the fossil was from a true aetosaur. However, a reevaluation in 2003 upon the relocation of the material showed that it was in fact an aetosaur and that the strata were of Triassic age. [3]
Based on similarities in the armour plating, Chilenosuchus seems to be closely related to Typothorax . It has been proposed to be a member of a recently devised clade, Typothoracisinae, along with Typothorax and several other similar aetosaurs. [4] However, because of the many other differences between it and other aetosaurs, the position of Chilenosuchus within Stagonolepididae will remain uncertain until more material can be found.
Aetosaurs are heavily armored reptiles belonging to the extinct order Aetosauria. They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned snouts, erect limbs, and a body ornamented with four rows of plate-like osteoderms. Aetosaur fossil remains are known from Europe, North and South America, parts of Africa, and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stratigraphic ranges were relatively short. Therefore, the presence of particular aetosaurs can accurately date a site in which they are found.
Aetosaurus is an extinct genus of pseudosuchian reptile belonging to the order Aetosauria. It is generally considered to be the most primitive aetosaur. Three species are currently recognized: A. ferratus, the type species from Germany and Italy; A. crassicauda from Germany; and A. arcuatus from eastern North America. Additional specimens referred to Aetosaurus have been found in the Chinle Group of the southwestern United States, and the Fleming Fjord Formation of Greenland. Specimens of Aetosaurus occur in Norian-age strata.
Aetosauroides is an extinct genus of aetosaur from the Late Triassic of South America. It is one of four aetosaurs known from South America, the others being Neoaetosauroides, Chilenosuchus and Aetobarbakinoides. Three species have been named: the type species A. scagliai, A. subsulcatus and A. inhamandensis. Fossils have been found in the Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina and the Santa Maria Formation in the Paraná Basin in southeastern Brazil. The strata date to the late Carnian and early Norian stages, making Aetosauroides one of the oldest aetosaurs.
Chiliques is a stratovolcano located in the Antofagasta Region of Chile.
Typothorax is an extinct genus of typothoracine aetosaur that lived in the Late Triassic. Its remains have been found in North America. Two species are known: T. coccinarum, the type species, and T. antiquum.
The Colloncuran age is a period of geologic time within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Friasian and precedes the Laventan age.
Ebrachosaurus is an extinct genus of aetosaur. It was named after the town of Ebrach, Germany, near an outcrop of the Blasensandstein Formation where the original fossils have been found. Other Blasensandstein fauna include the temnospondyl Metoposaurus and the phytosaur Francosuchus. The genus has often been considered synonymous with the closely related Stagonolepis. The holotype specimen was lost during World War II, so its relationships within Stagonolepididae remain indeterminant.
Neoaetosauroides is an extinct genus of primitive aetosaur. Its type and only species is N. engaeus. Fossils have been found in Los Colorados Formation outcropping along the Sierra Morada River in the Ischigualasto-Villa Unión Basin in La Rioja, Argentina, and date back to the Norian age of the Late Triassic. It was the first aetosaur known from the formation, with remains being discovered in the 1960s.
Hoplitosuchus is an extinct genus of aetosaur. Fossils have been found from the Santa Maria Formation in Rio Grande do Sul, Brazil that date back to the Late Triassic. At first the genus was named Hoplitosaurus, but this name had previously been assigned to a polacanthine ankylosaurian dinosaur in 1902, thirty-six years before it had been referred to the aetosaur. Thus Hoplitosuchus was constructed as a replacement name for Hoplitosaurus. Because the holotype specimen consists of unidentifiable osteoderms and any other material attributed to the genus may actually be considered a composite of rauisuchian and dinosaurian remains, Hoplitosuchus is now considered to be a nomen dubium. The saurischian dinosaur Teyuwasu was named in 1999 on the basis of material originally attributed to Hoplitosuchus.
Paratypothorax is an extinct genus of aetosaur, known from a single species, Paratypothorax andressorum. It was a broadly distributed member of the group found in Germany, North America, and possibly parts of Gondwana. The best specimens come from Germany, though for more than a century they were mistakenly considered phytosaur armor. Paratypothorax was a large and wide-bodied typothoracine aetosaur, as well as the namesake of the tribe Paratypothoracisini.
The Hornitos Formation is a Campanian geologic formation of the Algarrobal Basin in the Atacama Region of northern Chile. The formation comprises limestones, sandstones, conglomerates, marls and tuff. Dinosaur remains are among the fossils that have been recovered from the formation, including the sauropod Arackar licanantay.
Neuquén Basin is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the west with the Andean Volcanic Belt, to the southeast with the North Patagonian Massif and to the northeast with the San Rafael Block and to the east with the Sierra Pintada System. The basin covers an area of approximately 120,000 square kilometres (46,000 sq mi). One age of the SALMA classification, the Colloncuran, is defined in the basin, based on the Collón Curá Formation, named after the Collón Curá River, a tributary of the Limay River.
Choiyoi Group is a Permian and Triassic-aged group of volcano-sedimentary formations in Argentina and Chile. The group bears evidence of bimodal-style volcanism related to an ancient subduction zone that existed along the western margin of the supercontinent Gondwana.
Mejillones Peninsula protrudes from the coast of northern Chile north of Antofagasta and south of the port of Mejillones.
La Negra Formation is a geologic formation of Jurassic age, composed chiefly of volcanic and volcaniclastic rocks, located in the Coast Range of northern Chile. The formation originated in marine and continental (terrestrial) conditions, and bears evidence of submarine volcanism as well as large explosive eruptions. The volcanism of La Negra Formation is thought to have lasted for about five million years.
Estratos de Pupunahue is the name given to the sedimentary strata of Oligocene-Miocene age that crop out in Pupunahue and Mulpún near Valdivia, Chile. Outside this locality Estratos de Pupunahue extends below the surface over a larger area. The thickness of the strata varies from a few meters to 530 meters. The strata were initially described by Henning Illies. The strata are made up of conglomerate, sandstone and mudstone. The clast of the conglomerates are made up of metamorphic rock and the disposition of the conglomerates varies from clast-supported to matrix-supported. The sandstone and mudstone contain layers of lignite coal that exceed 30 cm in thickness.
Mulpún is a coal mine and locality in Los Ríos Region, Chile. Mulpún lies in the commune of Máfil a few kilometers to the west of the Chile Route 5 and north of the Calle-Calle and San Pedro River.
The Cuche Formation is a geological formation of the Floresta Massif, Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, and sandstone beds dates to the Late Devonian and Early Carboniferous periods, and has a maximum thickness of 900 metres (3,000 ft).
The Geste Formation is a fossiliferous geologic formation of the Puna Plateau in the western Salta Province and northern Catamarca Province of the Argentine Northwest, northwestern Argentina.
Land vertebrate faunachrons (LVFs) are biochronological units used to correlate and date terrestrial sediments and fossils based on their tetrapod faunas. First formulated on a global scale by Spencer G. Lucas in 1998, LVFs are primarily used within the Triassic Period, though Lucas later designated LVFs for other periods as well. Eight worldwide LVFs are defined for the Triassic. The first two of these LVFs, the Lootsbergian and Nonesian, are based on South African synapsids and faunal assemblage zones estimated to correspond to the Early Triassic. These are followed by the Perovkan and Berdyankian, based on temnospondyl amphibians and Russian assemblages estimated to be from the Middle Triassic. The last four LVFs, the Otischalkian, Adamanian, Revueltian, and Apachean, are based on aetosaur and phytosaur reptiles common in the Late Triassic of the southwestern United States.
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