Oldman Formation | |
---|---|
Stratigraphic range: Campanian, | |
Type | Geological formation |
Unit of | Belly River Group |
Underlies | Dinosaur Park Formation |
Overlies | Foremost Formation |
Thickness | up to 328 feet (100 m) [1] |
Lithology | |
Primary | Sandstone |
Other | Mudstone and bentonite |
Location | |
Coordinates | 49°37′41″N112°53′23″W / 49.62806°N 112.88972°W |
Region | Western Canada Sedimentary Basin |
Country | Canada |
Type section | |
Named for | Oldman River |
Named by | Russell, L.S. and Landes, R.W. |
Year defined | 1940 [2] |
The Oldman Formation is a stratigraphic unit of Late Cretaceous (Campanian stage) age that underlies much of southern Alberta, Canada. It consists primarily of sandstones that were deposited in fluvial channel and floodplain environments. It was named for exposures along the Oldman River between its confluence with the St. Mary River and the city of Lethbridge, and it is known primarily for its dinosaur remains and other fossils. [3]
The Oldman Formation is composed primarily of light-colored, fine-grained sandstones. They are upward-fining, lenticular to sheet-like bodies that are yellowish, steep-faced and blocky in outcrop. The formation also includes lesser amounts of siltstone and mudstone. [4]
The sediments of the Oldman Formation were deposited in fluvial channels (the sandstones) and a variety of channel margin, overbank and floodplain environments (the siltstones and mudstones). The formation is about 40 metres (130 ft) thick at Dinosaur Provincial Park in southeastern Alberta. It thickens toward the southwest, and northwestern Montana appears to have been the primary source of the sediments. [4]
The Oldman Formation is a member of the Belly River Group (also known as the Judith River Group). It conformably overlies the Foremost Formation, and is separated from the overlying Dinosaur Park Formation by a regional disconformity. The sediments of the Oldman are superficially similar to those of the Dinosaur Park, which was included in the Oldman Formation prior to the recognition of the disconformity. The two formations can also be distinguished by petrographic and sedimentologic differences. [3] [4]
The Oldman Formation was deposited during the middle Campanian, between about 77.5 and 76.5 million years ago. [5] It lies fully within magnetic polarity Chron 33n. [6]
List of dinosaurs found in the formation: [5] [7]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Theropods of the Oldman Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Daspletosaurus | D. torosus | Lower | Several specimens with a complete skeleton | A tyrannosaurid | ||
Unnamed species [8] | Upper | A skull | A new species of tyrannosaurid | |||
Dromaeosaurus | Indeterminate | Teeth | A dromaeosaurid | |||
Hesperonychus | H. elizabethae | Foot claw | A dromaeosaurid | |||
Paronychodon | Indeterminate | Teeth | A troodontid | |||
Prismatoolithus [9] | P. levis | Partial clutch containing 12 eggs | ||||
Ricardoestesia | R. isosceles | Misreported | ||||
Indeterminate | Teeth | A dromaeosaurid | ||||
Saurornitholestes | S. langstoni | Partial remains | A dromaeosaurid | |||
Troodon | Dubious | Teeth, eggs, embryos | A dubious taxon of troodontid, most specimens formerly considered Troodon have been reassigned to other genera such as Stenonychosaurus | |||
Struthiomimus | S. altus | Several specimens, including a nearly complete skeleton [10] | An ornithomimid | |||
Ornithischians of the Oldman Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Albertaceratops | A. nesmoi | Lower | Single Skull | A ceratopsid | ||
Albertadromeus [11] | A. syntarsus | Upper | A thescelosaurid | |||
Anchiceratops | Indeterminate | A ceratopsid | ||||
Brachylophosaurus | B. canadensis | Upper | Skull And partial skeleton | A hadrosaurid | ||
Chasmosaurus | C. brevirostris | Junior synonym of C. russelli | ||||
C. russelli | Upper | A ceratopsid, also found in the Dinosaur Park Formation | ||||
Coronosaurus | C. brinkmani | Upper | A ceratopsid | |||
Corythosaurus | C. casuarius | Upper | A hadrosaurid, also found in the Dinosaur Park Formation | |||
Foraminacephale | F. brevis | Also known from the Dinosaur Park Formation [12] | A pachycephalosaurid, once thought to be a species of Stegoceras | |||
Gremlin [13] | G. slobodorum | Lower | A right frontal | A leptoceratopsid | ||
Hanssuesia | H. sternbergi | Upper, also present in the Dinosaur Park Formation and Judith River Formation | skull dome | A pachycephalosaurid, potentially synonymous with Stegoceras validum [14] | ||
Maiasaura | M. peeblesorum | Upper | A hadrosaurid, also known from the Two Medicine Formation. [15] | |||
Parasaurolophus | P. walkeri | Upper | A hadrosaurid, also found in the Dinosaur Park Formation | |||
Scolosaurus | S. cutleri | Upper | An ankylosaurid, may actually be from the Dinosaur Park Formation | |||
Wendiceratops | W. pinhornensis | Lower | Partial Skeleton And Partial Skull | A centrosaurine | ||
An unnamed orodromine | Unnamed | Upper | An orodromine distinct from Albertadromeus. Closer to Oryctodromeus than to Albertadromeus, Orodromeus , and Zephyrosaurus . [11] |
A bone bed is any geological stratum or deposit that contains bones of whatever kind. Inevitably, such deposits are sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätte. It is also applied to brecciated and stalagmitic deposits on the floor of caves, which frequently contain osseous remains.
Philip John Currie is a Canadian palaeontologist and museum curator who helped found the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and is now a professor at the University of Alberta in Edmonton. In the 1980s, he became the director of the Canada-China Dinosaur Project, the first cooperative palaeontological partnering between China and the West since the Central Asiatic Expeditions in the 1920s, and helped describe some of the first feathered dinosaurs. He is one of the primary editors of the influential Encyclopedia of Dinosaurs, and his areas of expertise include theropods, the origin of birds, and dinosaurian migration patterns and herding behavior. He was one of the models for palaeontologist Alan Grant in the film Jurassic Park.
Chirostenotes is a genus of oviraptorosaurian dinosaur from the late Cretaceous of Alberta, Canada. The type species is Chirostenotes pergracilis.
Caenagnathus is a genus of caenagnathid oviraptorosaurian dinosaur from the late Cretaceous period. It is known from partial remains including lower jaws, a tail vertebra, hand bones, and hind limbs, all found in the Dinosaur Park Formation of Alberta, Canada. Caenagnathus measured about 2.5 m (8.2 ft) long and weighed about 96–100 kg (212–220 lb).
The Dinosaur Park Formation is the uppermost member of the Belly River Group, a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76.5 and 74.4 million years ago. It was deposited in alluvial and coastal plain environments, and it is bounded by the nonmarine Oldman Formation below it and the marine Bearpaw Formation above it.
Panoplosaurus is a genus of armoured dinosaur from the Late Cretaceous of Alberta, Canada. Few specimens of the genus are known, all from the middle Campanian of the Dinosaur Park Formation, roughly 76 to 75 million years ago. It was first discovered in 1917, and named in 1919 by Lawrence Lambe, named for its extensive armour, meaning "well-armoured lizard". Panoplosaurus has at times been considered the proper name for material otherwise referred to as Edmontonia, complicating its phylogenetic and ecological interpretations, at one point being considered to have existed across Alberta, New Mexico and Texas, with specimens in institutions from Canada and the United States. The skull and skeleton of Panoplosaurus are similar to its relatives, but have a few significant differences, such as the lumpy form of the skull osteoderms, a completely fused shoulder blade, and regularly shaped plates on its neck and body lacking prominent spines. It was a quadrupedal animal, roughly 5 m (16 ft) long and 1,600 kg (3,500 lb) in weight. The skull has a short snout, with a very domed surface, and bony plates directly covering the cheek. The neck had circular groups of plates arranged around the top surface, both the forelimb and hindlimb were about the same length, and the hand may have only included three fingers. Almost the entire surface of the body was covered in plates, osteoderms and scutes of varying sizes, ranging from large elements along the skull and neck, to smaller, round bones underneath the chin and body, to small ossicles that filled in the spaces between other, larger osteoderms.
Prenoceratops, is a genus of herbivorous ceratopsian dinosaur from the Late Cretaceous Period. It was a relatively small dinosaur, reaching 1.3 m (4.3 ft) in length and 20 kg (44 lb) in body mass. Its fossils have been found in the upper Two Medicine Formation in the present-day U.S. state of Montana, in Campanian age rock layers that have been dated to 74.3 million years ago. Fossils were also found in the Oldman Formation in the modern day Canadian province of Alberta, dating to around 77 million years ago.
The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between 83.5 ± 0.7 Ma and 70.6 ± 3.4 Ma, during Campanian time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas.
The Judith River Formation is a fossil-bearing geologic formation in Montana, and is part of the Judith River Group. It dates to the Late Cretaceous, between 79 and 75.3 million years ago, corresponding to the "Judithian" land vertebrate age. It was laid down during the same time period as portions of the Two Medicine Formation of Montana and the Oldman Formation of Alberta. It is an historically important formation, explored by early American paleontologists such as Edward Drinker Cope, who named several dinosaurs from scrappy remains found here on his 1876 expedition. Modern work has found nearly complete skeletons of the hadrosaurid Brachylophosaurus.
The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller.
The Nemegt Formation is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. The formation consists of river channel sediments and contains fossils of fish, turtles, crocodilians, and a diverse fauna of dinosaurs, including birds.
The Milk River Formation is a sandstone-dominated stratigraphic unit of the Western Canada Sedimentary Basin in southern Alberta, Canada. It was deposited in near-shore to coastal environments during Late Cretaceous time. Based on uranium-lead dating, palynology and stratigraphic relationships, deposition occurred between ~84.1 and 83.6 Ma.
The Foremost Formation is a stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of Foremost and is known primarily for its dinosaur remains and other fossils.
The Wapiti Formation is a geological formation of the Western Canada Sedimentary Basin in northwestern Alberta, and northeastern British Columbia, Canada. Its deposition spanned the time interval from the lower Campanian through to the upper Maastrichtian, between approximately 80 and 68 Ma. It was named by G.M. Dawson in 1881, presumably for exposures along the lower part of the Wapiti River and downstream along the Smoky River in Alberta.
The Cerro del Pueblo Formation is a geological formation in Coahuila, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. The formation is believed to correlate with the Baculites reesidesi and Baculites jenseni ammonite zones, which dates it to 73.63-72.74 Ma.
Albertadromeus is an extinct genus of orodromine thescelosaurid dinosaur known from the upper part of the Late Cretaceous Oldman Formation of Alberta, Canada. It contains a single species, Albertadromeus syntarsus.
Orodrominae is a subfamily of thescelosaurid dinosaurs known from the Cretaceous of North America and Asia.