Tecomazuchil Formation | |
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Stratigraphic range: | |
Type | Geological Formation |
Underlies | Chimeco Limestone |
Overlies | Acatlán Complex |
Lithology | |
Primary | Silty Sandstone [1] |
Location | |
Region | Puebla Province |
Country | Mexico |
Type section | |
Named by |
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The Tecomazuchil Formation is a geologic formation in Oaxaca, Mexico. It is made up of "a basal conglomerate 135 m thick and predominantly composed of quartz and metamorphic rock fragments, overlain by about 600 m of interbedded tan to red conglomerates, sandstones, and siltstones. The Tecomazuchil Formation overlies unconformably the Acatlán Complex and has been assigned a Middle Jurassic age, though it could represent at least part of the Oxfordian." [2] Fossil Bennettitales have been found in the formation. [3]
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
Bennettitales is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales were amongst the most common seed plants of the Mesozoic, and had morphologies including shrub and cycad-like forms. The foliage of bennettitaleans is superficially nearly indistinguishable from that of cycads, but they are distinguished from cycads by their more complex flower-like reproductive organs, at least some of which were likely pollinated by insects.
Williamsonia is a genus of plant belonging to Bennettitales, an extinct order of seed plants. Within the form classification system used in paleobotany, Williamsonia is used to refer to female seed cones, which are associated with plants that also bore the male flower-like reproductive structure Weltrichia.
The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau area of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Originally suggested as being Sinemurian-Pliensbachian, but more recent dating of detrital zircons has yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcian age is more likely. A previous depth work recovered a solid "Carixian" age from measurements done in the Tenney Canyon. More recent works have provided varied datations for the layers, with samples from Colorado and Arizona suggesting 197.0±1.5-195.2±5.5 Ma, while the topmost section is likely Toarcian or close in age, maybe even recovering terrestrial deposits coeval with the Toarcian Oceanic Anoxic Event. This last age asignation also correlated the Toarcian Vulcanism on the west Cordilleran Magmatic Arc, as the number of grains from this event correlate with the silt content in the sandstones of the upper layers.
The La Boca Formation is a geological formation in Tamaulipas state, northeast Mexico. It was originally thought to date back to the Early Jurassic, concretely the Pliensbachian stage epoch of 193-184 Ma. Later studies found that while the unit itself was likely deposited during the earliest Pliensbachian, as proven by zircon dating 189.0 ± 0.2 Ma, the local vulcanism continued until the Bajocian.
The Houcheng Formation is a geological formation in Hebei, China whose strata date back to the Upper Middle Jurassic. The lithology primarily consists of sandstone and conglomerate deposited in fluvial, alluvial fan and fan delta conditions, with interbeds of volcanic rocks. Dinosaur remains are among the fossils that have been recovered from the formation.
Vinctifer is an extinct genus of prehistoric bony fish erected by David Starr Jordan in 1919.
The Valtos Sandstone Formation is a Middle Jurassic (Bathonian) formation found in the Inner Hebrides of Scotland. It is the thickest member of the Great Estuarine Group. The lithology consists of sets of approximately 6 metre thick cross bedded sandstone, capped by thin shelly limestones containing bivalves of the genus Neomiodon Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
The Tochikubo Formation is a Jurassic geologic formation in northern Honshu, Japan, dating to the Oxfordian stage of the Late Jurassic. Fossil ornithopod tracks have been reported from the formation. As well as the Bennettitalean Kimuriella.
Zamites is a genus of sterile foliage known from the Mesozoic of North America, Europe, India and Antarctica through the Eocene of North America. It was erected as a form taxon for leaves that superficially resembled the extant cycad Zamia, however it is now believed to belong to a similar but phylogenetically different group, the cyacadeoids (Bennettitales). The fronds are linear or lanceolate in shape, and pinnately compound, with pinnae with parallel veins and smooth margins, and symmetrical and constricted at the base where they are attached obliquely to the upper surface of the rachis. It has been interpreted as a Bennettitalean plant in the family Williamsoniaceae. It is associated with the ovulate cone Williamsonia and male cone Weltrichia.
The Trujillo Formation is a geologic formation in Texas and New Mexico. It preserves fossils dating back to the upper Triassic period. It is also known as the Trujillo Sandstone.
The Rock Point Formation is a geologic formation in New Mexico, Arizona, and Utah. It preserves fossils dating back to the late Triassic.
The Conglomerado Cualac is a geologic formation in Mexico. First described by Guzmán in 1959, under the name Cuarcita Cualac. Later, Erben (1956) gave it their actual name. It consist of thick beds of a hard, white and sometimes yellowish conglomerate with a cuarcitic matrix. This conglomerate compounds almost exclusively of milky quartz pebbles between .5 and 5 centimeters of diameter. It also presents, in less quantity, pebbles of schist, gneiss, and tuff. Its thickness varies between 30 and more than 200 meters. It preserves fossils dating back to the Jurassic period.
The Zorrillo Formation is a geologic formation in Mexico, near Tezoatlán de Segura y Luna, Oaxaca. It preserves fossils dating back to the Jurassic period.
The Moskvoretskaya Formation is a Middle Jurassic geologic formation in the European part of Russia. It consists of continental claystones, siltstones and sandstones deposited in karstified segments of underlying Middle Carboniferous limestone, that would have formed underground aquifers.
The Hell-to-Finish Formation is a geologic formation in southwestern New Mexico. It preserves fossils dating back to the early Cretaceous period.
This article records new taxa of fossil plants that are scheduled to be described during the year 2021, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2021.
The Broken Jug Formation is a geologic formation in southwestern New Mexico. It was likely deposited in the late Jurassic period.
Pelourdea is an extinct genus of conifer. Species belonging to the genus lived from the Triassic to the Middle Jurassic and have been found in Europe and North America.
Weltrichia is a genus belonging to the extinct seed plant group Bennettitales. It is a form genus representing flower-like male pollen-producing organs. It is associated with the female ovulate cone Williamsonia.