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Neutron tomography is a form of computed tomography involving the production of three-dimensional images by the detection of the absorbance of neutrons produced by a neutron source. [1] It creates a three-dimensional image of an object by combining multiple planar images with a known separation. [2] It has a resolution of down to 25 μm. [3] [4] Whilst its resolution is lower than that of X-ray tomography, it can be useful for specimens containing low contrast between the matrix and object of interest; for instance, fossils with a high carbon content, such as plants or vertebrate remains. [5]
Neutron tomography can have the unfortunate side-effect of leaving imaged samples radioactive if they contain appreciable levels of certain elements such as cobalt, [5] however in practice this neutron activation is low and short-lived such that the method is considered non-destructive.
The increasing availability of neutron imaging instruments at research reactors and spallation sources via peer-reviewed user access programs [6] has seen neutron tomography achieve increasing impact across diverse applications including earth sciences, palaeontology, cultural heritage, materials research and engineering. In 2022, it was reported in the journal Gondwana Research that an ornithopod dinosaur was serendipitously discovered by neutron tomography in the gut content of Confractosuchus , a Cretaceous crocodyliform from the Winton Formation of central Queensland, Australia. [7] This is the first time that a dinosaur has been discovered using neutron tomography, and to this day, the partially digested dinosaur remains entirely embedded within the surrounding matrix. [8]
Multituberculata is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, and reached a peak diversity during the Late Cretaceous and Paleocene. They eventually declined from the mid-Paleocene onwards, disappearing from the known fossil record in the late Eocene. They are the most diverse order of Mesozoic mammals with more than 200 species known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals—Theria, including placentals and marsupials, and Monotremata—but usually as closer to Theria than to monotremes. They are considered to be closely related to Euharamiyida and Gondwanatheria as part of Allotheria.
Placerias is an extinct genus of dicynodonts that lived during the Carnian to the Norian age of the Triassic Period. Placerias belongs to a group of dicynodonts called Kannemeyeriiformes, which was the last known group of dicynodonts before the taxon became extinct at the end of the Triassic.
The South Polar region of the Cretaceous comprised the continent of East Gondwana–modern day Australia, Zealandia, and Antarctica–a product of the break-up of Gondwana in the Cretaceous Period. The southern region, during this time, was much warmer than it is today, ranging from perhaps 4–8 °C (39–46 °F) in the latest Cretaceous Maastrichtian in what is now southeastern Australia. This prevented permanent ice sheets from developing and fostered polar forests, which were largely dominated by conifers, cycads, and ferns, and relied on a temperate climate and heavy rainfall. Major fossil-bearing geological formations that record this area are: the Santa Marta and Sobral Formations of Seymour Island off the Antarctic Peninsula; the Snow Hill Island, Lopez de Bertodano, and the Hidden Lake Formations on James Ross Island also off the Antarctic Peninsula; and the Eumeralla and Wonthaggi Formations in Australia.
Archaeornithomimus is a genus of ornithomimosaurian theropod dinosaur that lived in Asia during the Late Cretaceous period, around 96 million years ago in the Iren Dabasu Formation.
Megaraptor is a genus of large theropod dinosaur that lived in the ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Initially thought to have been a giant dromaeosaur-like coelurosaur, it was classified as a neovenatorid allosauroid in previous phylogenies, but more recent phylogeny and discoveries of related megaraptoran genera has placed it as either a basal tyrannosauroid or a basal coelurosaur with some studies still considering it a neovenatorid.
The Bayan Shireh Formation is a geological formation in Mongolia, that dates to the Cretaceous period. It was first described and established by Vasiliev et al. 1959.
The Huincul Formation is a geologic formation of Late Cretaceous age of the Neuquén Basin that outcrops in the Mendoza, Río Negro and Neuquén Provinces of northern Patagonia, Argentina. It is the second formation in the Río Limay Subgroup, the oldest subgroup within the Neuquén Group. Formerly that subgroup was treated as a formation, and the Huincul Formation was known as the Huincul Member.
The Maevarano Formation is a Late Cretaceous sedimentary rock formation found in the Mahajanga Province of northwestern Madagascar. It is most likely Maastrichtian in age, and records a seasonal, semiarid environment with rivers that had greatly varying discharges. Notable animal fossils recovered include the theropod dinosaur Majungasaurus, the early bird Vorona, the paravian Rahonavis, the titanosaurian sauropod Rapetosaurus, and the giant frog Beelzebufo.
The Winton Formation is a Cretaceous geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age. The formation blankets large areas of central-western Queensland. It consists of sedimentary rocks such as sandstone, siltstone and claystone. The sediments that make up these rocks represent the remnants of the river plains that filled the basin left by the Eromanga Sea - an inland sea that covered large parts of Queensland and central Australia at least four times during the Early Cretaceous. Great meandering rivers, forest pools and swamps, creeks, lakes and coastal estuaries all left behind different types of sediment.
The Toolebuc Formation is a geological formation that extends from Queensland across South Australia and the Northern Territory in Australia, whose strata date back to the Albian stage of the Early Cretaceous. Dinosaurs, pterosaurs, plesiosaurs, ichthyosaurs, protostegid turtles, sharks, chimaeroids and bony fish remains are among the fossils that have been recovered from the 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 locality.
The Adamantina Formation is a geological formation in the Bauru Basin of western São Paulo state, in southeastern Brazil.
Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe, Africa, North America and South America. The pholidosaurids first appeared in the fossil record during the Bathonian stage of the Middle Jurassic. Jouve & Jalil (2020) described postcranial material of a pholidosaurid from the Paleocene (Danian) of Ouled Abdoun Basin (Morocco), representing the most recent record of the family. The authors also reinterpreted putative Maastrichtian dyrosaurid Sabinosuchus as a pholidosaurid, and argued that at least two independent pholidosaurid lineages reached the Maastrichtian, among which one survived the Cretaceous–Paleogene extinction event. Before the publication of this study it was thought that the family became extinct during the Late Turonian stage of the Late Cretaceous.
The Elrhaz Formation is a geological formation in Niger, West Africa.
The Csehbánya Formation is a geological formation in the Transdanubian Mountains of Veszprém County, Hungary. The formation dates to the Late Santonian of the Late Cretaceous. It represents a floodplain environment as opposed to the swampy lacustrine environment of the simultaneous Ajka Coal Formation, though there is complete overlap in terms of fauna. It underlies the Jákó Marl Formation, and laterally transitions to the Ajka Coal Formation.
Scott Donald Sampson is a Canadian paleontologist and science communicator. Sampson is currently the Executive Director of California Academy of Sciences in San Francisco, California. He was previously Vice President of Research & Collections and Chief Curator at the Denver Museum of Nature & Science,. Sampson is notable for his work on the carnivorous theropod dinosaurs Majungasaurus and Masiakasaurus and his extensive research into the Late Cretaceous Period, particularly in Madagascar. He is also known as the presenter of the PBS Kids show Dinosaur Train.
Pakasuchus is a genus of notosuchian crocodyliform distinguished by its unusual mammal-like appearance, including mammal-like teeth that would have given the animal the ability to chew. It also had long, slender legs and a doglike nose. Fossils have been found in the Galula Formation of Rukwa Rift Basin of southwestern Tanzania, and were described in 2010 in the journal Nature. Pakasuchus is originally considered to lived approximately 105 million years ago, in the mid-Cretaceous, but later age of site is reconsidered to the late Cretaceous, Cenomanian to Campanian instead. The type species is P. kapilimai. Pakasuchus means "cat crocodile" in reference to its catlike skull.
The Oulad Abdoun Basin is a phosphate sedimentary basin located in Morocco, near the city of Khouribga. It is the largest in Morocco, comprising 44% of Morocco's phosphate reserves, and at least 26.8 billion tons of phosphate. It is also known as an important site for vertebrate fossils, with deposits ranging from the Late Cretaceous (Cenomanian-Turonian) to the Eocene epoch (Ypresian), a period of about 25 million years.
Confractosuchus is a genus of extinct eusuchian crocodyliform from the Cretaceous Winton Formation of Australia. Described as a macro-generalist, Confractosuchus was found with the bones of a juvenile ornithopod dinosaur in its abdomen. It currently contains a single species, Confractosuchus sauroktonos, which literally means "broken dinosaur killer."
Patagopelta is an extinct genus of nodosaurine dinosaur from the Late Cretaceous Allen Formation of Argentina. The genus contains a single species, P. cristata, known from a partial skeleton. Patagopelta is a very small ankylosaur, comparable in size to the dwarf nodosaurid Struthiosaurus, about 2 m (6.6 ft) long.