The Dockum is a Late Triassic (approximately late Carnian through Rhaetian, or 223–200 Ma) geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle.[1] The Dockum reaches a maximum thickness of slightly over 650 m but is usually much thinner. The Dockum rests on an unconformity over the Anisian (242–234 Ma) aged Anton Chico Formation.
The Dockum and Chinle Formation were deposited roughly at the same time and share many of the same vertebrates and plant fossils. They appear to have very similar paleoenviroments.[2] The two units are approximately separated by the Rio Grande in central New Mexico. This has led to controversy over the stratigraphic nomenclature for the Chinle and Dockum.[3]
^Dunay, R.E.; Fisher, M.J. (June 1979). "Palynology of the Dockum group (Upper Triassic), Texas, U.S.A.". Review of Palaeobotany and Palynology. 28 (1): 61–92. doi:10.1016/0034-6667(79)90025-3.
^Cornet, B. (1993). "Applications and limitations of palynology in age, climatic, and paleoenviromental analyses of Triassic sequences in North America". New Mexico Museum of Natural History Bulletin. 3: 75–93. Retrieved 1 September 2020.
^Lehman, T.M. (1994). "The saga of the Dockum Group and the case of the Texas/New Mexico boundary fault" (PDF). New Mexico Bureau of Mines & Mineral Resources Bulletin. 150: 37–51. Retrieved 1 September 2020.
The Dockum is a Late Triassic (approximately late Carnian through Rhaetian, or 223–200 Ma) geologic group found primarily on the Llano Estacado of western...
The Palynology of the Triassic DockumGroup of Texas, and its application to Stratigraphic problems of the DockumGroup (Ph.D. thesis). Pennsylvania State...
of a geological group, the Chinle Group. Some authors have controversially considered the Chinle to be synonymous to the DockumGroup of eastern Colorado...
Texas and New Mexico. It is one of several formations encompassed by the DockumGroup. The type area of the formation is situated in Garza County, Texas, southeast...
from the Late Triassic (middle Norian) middle Cooper Canyon Formation, DockumGroup, Texas, USA, and its implications on our understanding of the morphological...
Mexico. It is one of several formations encompassed by the Late Triassic DockumGroup. The lower unit of the Cooper Canyon Formation in Garza County to the...
Formation (SW USA) Cow Branch Formation (North Carolina and Virginia, USA) DockumGroup (Carnian – Norian)* (SW USA) Dolomia di Forni (Italy) Fleming Fjord Formation*...
continents, and fossils are particularly common in the Chinle Formation and DockumGroup of the southwestern United States. Most fossils have been found in Arizona...
from fragmentary saurischian fossils unearthed from the Upper Triassic DockumGroup of Texas. Later in the Triassic period, dinosaurs left more recognizable...
of the DockumGroup, they could not have been reworked into the Dockum sediments as inclusions. The inferred palaeoclimate of the DockumGroup would have...
Poposaurus (now considered a pseudosuchian) and the unnamed theropod from the DockumGroup of Texas (now assigned to the rauisuchian Postosuchus). In 1985, Charig...
Phytosaurs (Φυτόσαυροι in greek, meaning 'plant lizard') are an extinct group of large, mostly semiaquatic Late Triassic archosauriform reptiles. Phytosaurs...
Praia do Telheiro, Portugal Angular unconformity between the underlying DockumGroup and the overlying Exeter Sandstone at Steamboat Butte in the valley of...
Triassic of the United States. It lived in the Otis Chalk localities of the DockumGroup in Texas, around 223 million years ago. It was first described in 2015...
slopes of the Tecovas Shale above. The Tecovas Formation is a part of the DockumGroup with the Trujillo Formation. This multicolored Triassic unit consists...
collected from the Post Quarry of the lower Cooper Canyon Formation (DockumGroup) near Post, Garza County, Texas, US, and was one of many new discoveries...
of Gojirasaurus was discovered in the Cooper Canyon Formation of the DockumGroup near Revuelto Creek, Quay County, in New Mexico. This genus was discovered...
probably collected from the Bull Canyon Formation of the Chinle Group or DockumGroup, probably at the Bull Canyon, in the Guadalupe County of New Mexico...
of phytosaur known from the late Triassic period (Carnian stage) of DockumGroup in Texas, United States. It is known from the holotype UMMP 10336 is...
well as in New Mexico and Texas in the Bull Canyon Formation of the DockumGroup. Like all aetosaurs and many other early crurotarsans, Typothorax had...
paraphyletic group of mostly large and carnivorous Triassic archosaurs. Rauisuchians are a category of archosaurs within a larger group called Pseudosuchia...
North America: A new neotheropod from the base of the Upper Triassic DockumGroup of Texas" (PDF). Acta Palaeontologica Polonica. 60. doi:10.4202/app.00143...
an extinct genus of large temnospondyls known from the Late Triassic DockumGroup in Texas. The type species, B. bakeri, was long classified as part of...
specimen of Caseosaurus was discovered in the Tecovas Formation of the DockumGroup in Texas, in sediments deposited during the Norian stage of the Late...
occurred in the late 19th century when E.D. Cope classified armor from the DockumGroup in Texas, USA, as the new species Episcoposaurus haplocerus. Case later...
originally named Calyptosuchus, a stagonolepidid from the Late Triassic DockumGroup of the United States, which was considered to be a species of Stagonolepis...
flows out of the Canyon de Chelly. They were also possibly found in the DockumGroup. Chinlea was described by Schaeffer in 1967 from type specimen Chinlea...
1980s from the Post Quarry in the Late Triassic Cooper Canyon Formation (DockumGroup) of West Texas. The material includes the large rauisuchian Postosuchus...
to the DockumGroup. The proposal of Spencer G. Lucas and his collaborators to abandon the DockumGroup, possibly in favor of the Chinle Group, is highly...
Global Information
United States