A lagerstätte is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. Lagerstätten span geological time from the Neoproterozoic era to the present.
Mesosaurs were a group of small aquatic reptiles that lived during the early Permian period (Cisuralian), roughly 299 to 270 million years ago. Mesosaurs were the first known aquatic reptiles, having apparently returned to an aquatic lifestyle from more terrestrial ancestors. It is uncertain which and how many terrestrial traits these ancestors displayed; recent research cannot establish with confidence if the first amniotes were fully terrestrial, or only amphibious. Most authors consider mesosaurs to have been aquatic, although adult animals may have been amphibious, rather than completely aquatic, as indicated by their moderate skeletal adaptations to a semiaquatic lifestyle. Similarly, their affinities are uncertain; they may have been among the most basal sauropsids or among the most basal parareptiles.
Friedrich von Huene, born Friedrich Richard von Hoinigen, was a German paleontologist who renamed more dinosaurs in the early 20th century than anyone else in Europe. He also made key contributions about various Permo-Carboniferous limbed vertebrates.
Mesosaurus is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera Brazilosaurus and Stereosternum, it is a member of the family Mesosauridae and the order Mesosauria. Mesosaurus was long thought to have been one of the first marine reptiles, although new data suggests that at least those of Uruguay inhabited a hypersaline water body, rather than a typical marine environment. In any case, it had many adaptations to a fully aquatic lifestyle. It is usually considered to have been anapsid, although Friedrich von Huene considered it to be a synapsid. Recent study of Mesosauridae phylogeny places the group as either the basal most clade within Parareptilia or the basal most clade within Sauropsida despite the skull of Mesosaurus possessing the "Synapsid condition" of one temporal fenestra.
The Ecca Group is the second of the main subdivisions of the Karoo Supergroup of geological strata in southern Africa. It mainly follows conformably after the Dwyka Group in some sections, but in some localities overlying unconformably over much older basement rocks. It underlies the Beaufort Group in all known outcrops and exposures. Based on stratigraphic position, lithostratigraphic correlation, palynological analyses, and other means of geological dating, the Ecca Group ranges between Early to earliest Middle Permian in age.
Stereosternum tumidum is an extinct genus of mesosaur marine reptile from the Early Permian of Brazil and also the Great Karoo Basin of South Africa. The taxon mesosaur is a monophyletic group containing Brazilosaurus sanpauloensis and Mesosaurus tenuidens.
Sphenacanthus is an extinct genus of a chondrichtyan xenacanthiform that belongs to the Sphenacanthidae family and lived from the Late Devonian, through Carboniferous until the Late Permian period in Scotland, Spain, Russia and Brazil. It lived 359 million years ago, and probably it was one of the first member of the elasmobranchians, the lineage that leads to the modern sharks. Sphenacanthus probably hunts small fishes and, unlike their modern-day relatives, its inhabited fresh water lagoons. Sphenacanthus had seven fins, two in the upper part and five in the underside, and it had a heterodont dentition and mandibles relatively long and deeper. Sphenacanthus serrulatus is still only known from incomplete neurocranial remains and associated dermal material. These suggest that it was a relatively large shark, probably well over one meter in length when fully grown. Its body form was probably similar to that of other phalacanthous sharks.
Irati Formation is the name of a geological formation of the Paraná Basin in Brazil. It has previously been dated as Late Permian using palynomorphs, but is now dated as Early Permian using zircon ages obtained from bentonite layers. The base of the formation has been dated at 278.4 ± 2.2 Ma. Exposures of the Irati Formation are to be found in the South, southeastern Brazil and in the states of Goiás, Mato Grosso, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul and Mato Grosso do Sul. The formation is part of the Passa Dios Group, underlying the Serra Alta Formation and overlying the Palermo Formation. The formation has been deposited in a restricted marine environment. The Irati Formation, with a maximum thickness of 80 metres (260 ft), was defined and named by White in 1908.
The Paraná Basin is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande do Sul states. The remainder area is distributed in eastern Paraguay, northeastern Argentina and northern Uruguay. The shape of the depression is roughly elliptical and covers an area of about 1,500,000 km2 (580,000 sq mi).
Brazilosaurus is an extinct genus of mesosaur which lived during the early Permian of what is now Brazil. It is known from specimen BSPG 1965 I 131, a single skeleton recovered from the Assistencia Member of the Irati Formation, in the Paraná Basin. It was named by T. Shikama and H. Ozaki in 1966 and the type species is Brazilosaurus sanpauloensis.
Euromycter is an extinct genus of caseid synapsids that lived in what is now southern France during the Early Permian about 285 million years ago. The holotype and only known specimen of Euromycter (MNHN.F.MCL-2) includes the complete skull with lower jaws and hyoid apparatus, six cervical vertebrae with proatlas, anterior part of interclavicle, partial right clavicle, right posterior coracoid, distal head of right humerus, left and right radius, left and right ulna, and complete left manus. It was collected by D. Sigogneau-Russell and D. Russell in 1970 at the top of the M1 Member, Grès Rouge Group, near the village of Valady, Rodez Basin. It was first assigned to the species "Casea" rutena by Sigogneau-Russell and Russell in 1974. More recently, it was reassigned to its own genus, Euromycter, by Robert R. Reisz, Hillary C. Maddin, Jörg Fröbisch and Jocelyn Falconnet in 2011. The preserved part of the skeleton suggests a size between 1,70 m (5,5 ft) and 1,80 m (5,9 ft) in length for this individual.
This timeline of Permian research is a chronological listing of events in the history of geology and paleontology focused on the study of earth during the span of time lasting from 298.9–252.17 million years ago and the legacies of this period in the rock and fossil records.
Pappochelys is an extinct genus of diapsid reptile possibly related to turtles. The genus contains only one species, Pappochelys rosinae, from the Middle Triassic of Germany, which was named by paleontologists Rainer Schoch and Hans-Dieter Sues in 2015. The discovery of Pappochelys provides strong support for the placement of turtles within Diapsida, a hypothesis that has long been suggested by molecular data, but never previously by the fossil record. It is morphologically intermediate between the definite stem-turtle Odontochelys from the Late Triassic of China and Eunotosaurus, a reptile from the Middle Permian of South Africa.
The Huab Formation is an Early Permian geologic formation correlated with the Ecca Group and designated "Ecca" Group, because it does not belong to the Karoo, in the southwestern Kunene Region and northern Erongo Region of northwestern Namibia. The Huab Formation represents the oldest sedimentary unit of the Huab Basin, overlying the basement. The oil shales within the formation were deposited in a shallow lacustrine environment, and the formation marks the transition from terrestrial deposits under glacial climatic circumstances towards a warmer fluvial and marine deltaic environment.
The Whitehill Formation, alternatively written as White Hill Formation and formerly known as White Band or Whitehill or White Hill Member, is a regional Early Permian geologic formation belonging to the Ecca Group in the southeastern ǁKaras Region of southeastern Namibia and Eastern, Northern and Western Cape provinces of South Africa.
The Gai-As Formation is an Early to Middle Permian geologic formation correlated with the Ecca Group and designated "Ecca" Group, because it does not belong to the Karoo, in the southwestern Kunene Region and northern Erongo Region of northwestern Namibia. The Gai-As Formation represents the second-oldest sedimentary unit of the Huab Basin, overlying the Huab Formation. The formation was deposited in a fluvial to lacustrine setting.
The Bertie Group or Bertie Limestone, also referred to as the Bertie Dolomite and the Bertie Formation, is an upper Silurian geologic group and Lagerstätte in southern Ontario, Canada, and western New York State, United States. Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. The formation comprises dolomites, limestones and shales and reaches a thickness of 495 feet (151 m) in the subsurface, while in outcrop the group can be 60 feet (18 m) thick.
Graciela Helena Piñeiro Martínez is a Uruguayan biologist and paleontologist.
Uruguay 
