Nyker Group Stratigraphic range: Latest Jurassic to Early Cretaceous, 146–140 Ma | |
---|---|
Type | Geological unit |
Sub-units | Rabekke Formation, Robbedale Formation, Jydegaard Formation |
Underlies | Arnager Greensand Formation |
Overlies | Bagå Formation |
Lithology | |
Primary | Claystone and Sandstone |
Location | |
Region | Bornholm |
Country |
The Nyker Group is a group of geological formations from the Early Cretaceous, about 146 to 140 million years ago. It is on the island of Bornholm, Denmark. It includes the Rabekke, Robbedale and Jydegaard Formations. [1]
The Rabekke Formation is the lowermost formation of the Nyker Group. It dates to about 146 to 145 million years ago, at the Jurassic-Cretaceous boundary. The formation has the significance of having the first Scandinavian mammal, Sunnyodon notleyi, uncovered from it. Many crocodilomorphs and other vertebrates have been recovered from it. [2]
The Robbedale Formation is the middle formation of the Nyker Group. It dates to about 145 million years ago. No vertebrate fossils have been recovered from the formation. [1]
The Jydegaard Formation is the uppermost formation of the Nyker Group. It dates to around 145 to 140 million years ago. The first dinosaur found on Denmark, Dromaeosauroides bornholmensis, was discovered in this formation. [1] Many vertebrates have been recovered from it. [2]
The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. It is also called the Age of Reptiles and the Age of Conifers.
Daspletosaurus is a genus of tyrannosaurid dinosaur that lived in western North America between about 77 and 74 million years ago, during the Late Cretaceous Period. The genus Daspletosaurus contains two species. Fossils of the earlier type species, D. torosus, have been found in Alberta, while fossils of the later second species, D. horneri, have been found only in Montana. A possible third species, also from Alberta, awaits formal identification and another possible species D. degrootorum, also exists, but it may belong to the separate genus Thanatotheristes instead. Daspletosaurus is closely related to the much larger and more recent tyrannosaurid Tyrannosaurus rex. Like most tyrannosaurids, Daspletosaurus was a multi-tonne bipedal predator equipped with dozens of large, sharp teeth. Daspletosaurus had the small forelimbs typical of tyrannosaurids, although they were proportionately longer than in other genera.
Rapetosaurus is a genus of titanosaurian sauropod dinosaur that lived in Madagascar from 70 to 66 million years ago, at the end of the Cretaceous Period. Only one species, Rapetosaurus krausei, has been identified.
Richardoestesia is a medium-sized genus of theropod dinosaur from the late Cretaceous Period of what is now North America. It currently contains two species, R. gilmorei and R. isosceles.
Bactrosaurus is a genus of herbivorous dinosaur that lived in Asia during the Late Cretaceous, about 96 million years ago. The position Bactrosaurus occupies in the Cretaceous makes it one of the earliest known hadrosauroids, and although it is not known from a full skeleton, Bactrosaurus is one of the best known of these early hadrosauroids, making its discovery a significant finding.
Amazonsaurus is a genus of diplodocoid sauropod dinosaur from the Early Cretaceous Period of what is now South America. It would have been a large-bodied quadrupedal herbivore with a long neck and whiplash tail. Although more derived diplodocoids were some of the longest animals ever to exist, Amazonsaurus was probably not more than 12 meters (40 ft) long. Gregory S. Paul estimated in 2010 its weight at 5000 kg.
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.
Rhabdodon is a genus of ornithopod dinosaur that lived in Europe approximately 70-66 million years ago in the Late Cretaceous. It is similar in build to a very robust "hypsilophodont", though all modern phylogenetic analyses find this to be an unnatural grouping, and Rhabdodon to be a basal member of Iguanodontia.
The Lance (Creek) Formation is a division of Late Cretaceous rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas. The Lance Formation is Late Maastrichtian in age, and shares much fauna with the Hell Creek Formation of Montana and North Dakota, the Frenchman Formation of southwest Saskatchewan, and the lower part of the Scollard Formation of Alberta.
Amurosaurus is a genus of lambeosaurine hadrosaurid dinosaur found in the latest Cretaceous period of eastern Asia. Like most lambeosaurs, it would have been a primarily bipedal herbivore with a "duckbill" shaped snout and a hollow crest on top of its head, although such a crest has not been found. Fossil bones of adults are rare, but an adult would most likely have been at least 6 metres (20 ft) long. According to Gregory S. Paul, it was about 8 metres (26 ft) long and weighed about 3,000 kilograms (6,600 lb).
Hagryphus, is an oviraptorosaurian theropod dinosaur from the Upper Cretaceous Period of what is now Utah.
Dromaeosauroides is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous of what is now Denmark. It was discovered in the Jydegaard Formation in the Robbedale valley, on the island of Bornholm in the Baltic Sea. This is the only likely place for dinosaur remains to be discovered on Danish territory, since the Mesozoic deposits exposed in the rest of the country are marine. Dromaeosauroides is the first known dinosaur from this location, and the only one which has been scientifically named. It is one of the oldest known dromaeosaurs in the world, and the first known uncontested dromaeosaur from the Early Cretaceous of Europe.
Palintropus is a prehistoric bird genus from the Late Cretaceous. A single species has been named based on a proximal coracoid from the Lance Formation of Wyoming, dated to the latest Maastrichtian, 66 million years ago. Coracoids and a proximal scapula of two unnamed species from the upper Campanian Dinosaur Park Formation of Alberta, dating to between 76.5 and 75 million years ago, are also known.
The Douiret Formation is a geologic formation in Tunisia, near the Berber village of Douiret. It is part of the larger Continental Intercalaire Formation, which stretches from Algeria and Niger in the west to Egypt and Sudan in the east. The Douiret Formation is located in the Tataouine basin in southern Tunisia, stretching into Algeria and Libya, and is part of the Merbah el Asfer Group of rock formations. The Douiret is 80 metres thick and consists of a 30-metre layer of sand beneath a 50-metre layer of clay.
The Ojo Alamo Formation is a geologic formation in New Mexico spanning the Mesozoic/Cenozoic boundary.
Hollanda is a genus of small ground birds known from fossils found in the Barun Goyot Formation of Mongolia. Found at Khermeen Tsav, it dates from the late Cretaceous period, about 75 million years ago. Known only from partial hind limbs, Hollanda has long legs with an unusual configuration of the toes. These indicate that it was a fast-running ground bird, possibly similar to the modern Roadrunner. Its relationships are uncertain. Some studies have found that it was an relatively advanced bird, a member of the Ornithurae, related to birds like Ichthyornis. Other studies have recovered it as a member of the primitive family Songlingornithidae. A more expansive study found it as an enantiornithean.
The Jydegaard Formation is a geological formation dating to the Early Cretaceous, about 145-139 million years ago. It is on the island of Bornholm, Denmark. Vertebrate fossils have been found in the formation.
The Rabekke Formation is a geological formation dating to the latest Jurassic or earliest Cretaceous, around 146 to 145 million years ago. The formation crops out on the island of Bornholm, Denmark. Vertebrate fossils have been found in the formation.
The Robbedale Formation is a geological formation dating to the Berriasian stage of the Early Cretaceous, about 142 million years ago. It is on the island of Bornholm, Denmark.
The Bagå Formation is a geological formation dating to around 199 to 170 million years ago, in the Early and Late Jurassic. It is located on the island of Bornholm, Denmark.