Greene Formation | |
---|---|
Stratigraphic range: Early Permian, Kungurian | |
Type | Formation |
Unit of | Dunkard Group |
Overlies | Washington Formation |
Thickness | 200 metres (660 ft) |
Lithology | |
Primary | shale, mudstone, sandstone |
Other | limestone, coal |
Location | |
Region | Ohio West Virginia Pennsylvania |
Country | United States |
Type section | |
Named for | Greene County |
Greene Formation is a geologic formation located in Ohio, West Virginia and Pennsylvania that has been dated to the Seymouran Land-Vertebrate Faunachron of the Early Permian. It is the youngest formation within the Dunkard Group, putting it right above the Washington Formation stereographically. [1]
The geology of the Greene Formation mostly contains a mix of shaly sandstone and shale with facies containing limestone and coal. [2] Though the currently preserved thickness of the formation is around 200 meters, the top of the formation has been eroded away, making it impossible to tell the full depth of the formation. [1]
Genus | Species | Notes | Image |
---|---|---|---|
Barbclabornia [3] | B. luedersensis | A large xenocath shark from the Permian of North America. Due to the shape of the dentition, it is believed that it would have been a filter-feeder comparable to whale and basking sharks. [4] |
Genus | Species | Notes | Image |
---|---|---|---|
Sagenodus [5] | S. sp | A wide-spread genus of lungfish that shows a transitional phase between the Devonian and Post-Paleozoic lungfish structures. [6] Found at the Clark Hill locality, in the same quarry as Ctenospondylus and Trimerorhachis. [5] |
Genus | Species | Notes | Image |
---|---|---|---|
Brachydectes | B. sp | A small lysorophian that was orginally assigned to the genus Lysorophus though was later reassigned to the genus Brachydectes. [1] | |
Diploceraspis [7] | D. burkei | A diplocaulid and most well-known Nectridean from the formation, it's been suggested that the shape of the head caused by the extreme lengthening of the tabular and squamosal bones of the skull may be convergent to those found in Diplocaulus rather than from a common ancestor. [1] | |
Lysorophus [1] | L. dunkardensis | A small lysorophian with a serpent-like body and short limbs, it's questioned if the genus is valid though L. dunkardensis is still currently assigned to the genus. [1] | |
Megamolgophis [1] | M. agostinii | A very large lysorophian estimated at a length of 1.3 meters. Like other lysorophians, the animal's limbs were extremely small but unlike others, Megamologophis's vertebral centra were comparatively complicated. [8] |
Genus | Species | Notes | Image |
---|---|---|---|
Ctenospondylus [1] | C. ninevehensis | A large sphenacodontid with sorter neural spines than seen in Dimetrodon, the animal is also an index taxa for the Seymouran LVF. [1] | |
Edaphosaurus [8] | A large and widespread edaphosaurid that had spines coming off on the sides of its neural arches, a characteristic of the family. Just like seen in formations in Texas, there is a transition in the species between earlier and later strata of the group. Between the Washington and Greene formations, a shift from E. cf. E. boanerges to E. cf. E. cruciger. [1] | ||
Ophiacodon [1] | O. cf. O. uniformis | A large and late surviving ophiacodontid known from 10 vertebrae, along with an incomplete left forelimb. [9] |
Genus | Species | Notes | Image |
---|---|---|---|
Eryops [8] | E. cf. E. megacephalus | A large eryopid that is common throughout the Dunkard Group that looks most similar to E. megacephalus though this would make it the only member of the family to come from the group. [1] | |
Trimerorhachis [5] | T.sp | A medium-sized dvinosaurid with small-poorly ossified limbs, there's not much known about the specimen found in the Greene Formation, only that it was found in the same quarry as the holotype of Ctenospondylus ninevehensis. [5] [10] | |
Zatrachys [11] | Z. cf. Z. serratus | A zatrachydid known from a fairly complete skull, though it can't be assigned to a specific species within the genus. This is mainly because of some inconsistences in the sutural lines of the skull table when comparing them to those found in New Mexico. [11] |
Genus | Species | Notes | Image |
---|---|---|---|
Ambedus [12] | A. pusillus | A small tetrapodamorph originally classified as a diadectid though later studies have since concluded that the features in the teeth that placed the animal within the group were a result of convergent evolution. It's unknown if Ambedus is even within diadectimorpha. [13] |
Genus | Species | Notes | Image |
---|---|---|---|
Alethopteris [14] | ?A. sp | ||
Autunia [15] | A. conferta | ||
A. naumannii | |||
Lepidophylloides [14] | L. sp | ||
Lodevia [15] | L. oxydata | ||
Pecopteris [14] | ?P. sp | ||
Rhachiphyllum [15] | R. schenkii | ||
Sigillaria [14] | S. brardii | ||
S. sp. |
The paleoenvironment of the Greene Formation was a lake in a seasonal dry area shown by the large amounts of vertisols, especially when compared to earlier formations in the group. Around the lake there would have been both seed ferns and lycophytes though much fewer in numbers than earlier in the Dunkard Group; being shown by the steady decrease in the amount and depth of coal layers within the group. [15] The overall trends in the paleosols of the Greene Formation are seen in the general transition to more arid climates from the Pennsylvanian to Middle Permian. [16]
Diadectidae is an extinct family of early tetrapods that lived in what is now North America and Europe during the Late Carboniferous and Early Permian, and in Asia during the Late Permian. They were the first herbivorous tetrapods, and also the first fully terrestrial animals to attain large sizes. Footprints indicate that diadectids walked with an erect posture. They were the first to exploit plant material in terrestrial food chains, making their appearance an important stage in both vertebrate evolution and the development of terrestrial ecosystems.
In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between 298.9 and 293.52 million years ago (Ma). It was preceded by the Gzhelian and followed by the Sakmarian.
Dissorophidae is an extinct family of medium-sized temnospondyls that flourished during the late Carboniferous and early Permian periods. The clade is known almost exclusively from North America.
Platyhystrix is an extinct temnospondyl amphibian with a distinctive sail along its back, similar to the unrelated synapsids, Dimetrodon and Edaphosaurus. It lived during the boundary between the latest Carboniferous and earliest Permian periods throughout what is now known as the Four Corners, Texas, and Kansas about 300 million years ago.
Araeoscelidia or Araeoscelida is a clade of extinct amniotes superficially resembling lizards, extending from the Late Carboniferous to the Early Permian. The group contains the genera Araeoscelis, Petrolacosaurus, the possibly aquatic Spinoaequalis, and less well-known genera such as Kadaliosaurus and Zarcasaurus. This clade is usually considered to be the sister group to all later diapsids.
Zatrachys is an extinct genus of large and flat-headed zatracheid temnospondyl from the early Permian of North America.
Trematopidae is a family of dissorophoid temnospondyls spanning the late Carboniferous to the early Permian. Together with Dissorophidae, the family forms Olsoniformes, a clade comprising the medium-large terrestrial dissorophoids. Trematopids are known from numerous localities in North America, primarily in New Mexico, Oklahoma, and Texas, and from the Bromacker quarry in Germany.
The Allegheny Group, often termed the Allegheny Formation, is a Pennsylvanian-age geological unit in the Appalachian Plateau. It is a major coal-bearing unit in the eastern United States, extending through western and central Pennsylvania, western Maryland and West Virginia, and southeastern Ohio. Fossils of fishes such as Bandringa are known from the Kittaning Formation, which is part of the Allegheny Group.
Anconastes is an extinct genus of dissorophoid temnospondyl within the family Trematopidae. It is known from two specimens from the Late Carboniferous Cutler Formation of north-central New Mexico in the southwestern United States. The genus name derives from two Greek roots, ankos and nastes ("inhabitant"), which refers to the type locality of El Cobre Canyon where the specimens were found. The specific name is derived from the Latin word vesperus ("western"). The more complete specimen, the holotype, is a partial skull with articulated mandibles and a substantial amount of the postcranial skeleton. The less complete specimen, the paratype, consists only of the right margin of the skull with an articulated mandible.
Actiobates is an extinct genus of trematopid temnospondyl that lived during the Late Carboniferous. It is known from the Garnett Quarry in Kansas.
Acroplous is an extinct genus of dvinosaurian Temnospondyli within the family Eobrachyopidae.
Ecolsonia is an extinct genus of trematopid temnospondyl. Its phylogenetic position within Olsoniformes has been historically debated, but it is presently considered to be a trematopid.
Megamolgophis is an extinct genus of eel-like tetrapod, possibly belonging to the group Lysorophia. Fossils from this genus have been found in the Allegheny mountains of the eastern United States. The genus is endemic to geological formations of this area, such as the Greene and Washington formations of the Early Permian Dunkard Group, as well as the Pennsylvanian Conemaugh Group.
Ambedus is an extinct genus of possible diadectid reptiliomorph. Fossils have been found from the Early Permian Dunkard Group of Monroe County, Ohio. The type species A. pusillus was named in 2004. The genus name comes from the Latin word ambedo meaning "to nibble", in reference to its herbivorous diet. The specific name pusillus means "tiny" in Latin.
Adamanterpeton is a genus of Edopoid Temnospondyl within the family Cochleosauridae. The type species A. ohioensis was named in 1998 and is currently the only known species within this genus. Adamanterpeton is rare in the Linton vertebrate assemblage, with other amphibians like Sauropleura, Ophiderpeton, and Colosteus being more common. Unlike other Linton vertebrates, Adamanterpeton may have been adapted to a terrestrial lifestyle.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
The Monongahela Formation is a geologic formation in West Virginia, Pennsylvania, Ohio, and Maryland. It is dated to the Carboniferous period. The top of the group is marked by the Waynesburg Coal and its base is marked by the Pittsburgh coal seam. The Pittsburgh coal is the thickest and most extensive bituminous coal bed in the Appalachian Basin
The Washington Formation is a coal, sandstone, and limestone geologic formation located in Ohio, Pennsylvania and West Virginia. It dates back to the Lower Permian period, with its base at or near the Permian/Carboniferous boundary. The Washington formation and the Dunkard Group as a whole was deposited at a time when the continents were in the process of forming the "Super Continent" Pangaea as well as a gradual drop in sea levels. The result during this period was coals being thinner and impure with high ash content. The limestones found with in the formation are exclusively freshwater deposits.
The Archer City Formation is a geological formation in north-central Texas, preserving fossils from the Asselian and early Sakmarian stages of the Permian period. It is the earliest component of the Texas red beds, introducing a tropical ecosystem which will persist in the area through the rest of the Early Permian. The Archer City Formation is preceded by the cool Carboniferous swamp sediments of the Markley Formation, and succeeded by the equally fossiliferous red beds of the Nocona Formation. The Archer City Formation was not named as a unique geological unit until the late 1980s. Older studies generally labelled its outcrops as the Moran or Putnam formations, which are age-equivalent marine units to the southwest.
The El Cobre Canyon Formation is a geologic formation in New Mexico. It preserves fossils dating back to the late Pennsylvanian to early Permian periods.