Portland Formation | |
---|---|
Stratigraphic range: Hettangian-Sinemurian ~ | |
Type | Geological formation |
Unit of | Agawam Group, Newark Supergroup |
Sub-units | Turners Falls Sandstone & Mount Toby Formation |
Overlies | East Berlin Formation |
Lithology | |
Primary | Sandstone |
Other | Mudstone, siltstone, limestone |
Location | |
Coordinates | 42°18′N72°30′W / 42.3°N 72.5°W |
Approximate paleocoordinates | 24°00′N18°36′W / 24.0°N 18.6°W |
Region | Connecticut, Massachusetts |
Country | USA |
Extent | Deerfield & Hartford Basins |
The Portland Formation is a geological formation in Connecticut and Massachusetts in the northeastern United States. [1] It dates back to the Early Jurassic period. [2] The formation consists mainly of sandstone laid down by a series of lakes (in the older half of the formation) and the floodplain of a river (in the younger half). The sedimentary rock layers representing the entire Portland Formation are over 4 kilometres (2.5 mi) thick and were formed over about 4 million years of time, from the Hettangian age (lower half) to the late Hettangian and Sinemurian ages (upper half). [3]
In 2016, the paleontologist Robert E. Weems and colleagues suggested the Portland Formation should be elevated to a geological group within the Newark Supergroup (as the Portland Group), and thereby replacing the former name "Agawam Group". They also reinstated the Longmeadow Sandstone as a formation (within the uppermost Portland Group); it had earlier been considered identical to the Portland Formation. [4]
Dinosaur coprolites are known from the formation. [2] This formation and the underlying East Berlin Formation are well-known for its numerous well-preserved dinosaur tracks, which represent ornithischians, theropods, and sauropodomorphs, which are preserved at sites such as Dinosaur Footprints Reservation. [2] [5] Other tracks are also known representing animals such as pseudosuchians, turtles, and temnospondyls. [6]
Dinosaurs | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Anchisaurus [2] | A. polyzelus [2] | Several specimens. | A relatively small basal Sauropodomorph. Many Otozoum tracks in the formation that may belong to Anchisaurus could have been made by potentially even larger specimens of the genus. [7] | |||
Podokesaurus [2] | P. holyokensis | Massachusetts | Partial postcranial skeleton. [8] | A coelophysoid theropod. The only specimen was destroyed in a fire. | ||
Neotheropoda sp. [9] | Massachusetts | Partial humerus. | Estimated to have been 9 meters long, and possibly a semiaquatic piscivore. | |||
Theropoda sp. [10] | Connecticut | Bones and tracks attributed to "Anchisauripus" |
Non-dinosaur archosaurs | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Stegomosuchus [11] | S. longipes | Hine's Quarry, Longmeadow | Partial postcranial skeleton. | Originally Stegomus. A small armored "protosuchian" crocodyliform. | ||
Pterosauria sp. [12] | South Hadley, Massachusetts | Partial Wrist and tooth. | Non-pterodactyloid pterosaur estimated to have a wingspan of 40 cm. |
Fish | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Acentrophorus [13] | A. chicopensis | Material initially referred to the genus Acentrophorus . Most researchers consider the species distinct from Acentrophorus . | ||||
Redfieldius [14] | R. gracilis | The last surviving redfieldiiform fish. | ||||
Semionotus [14] | S. sp. | A semionotid fish. |
Insects | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Holcoptera | H. schlotheimi [15] | A coptoclavid beetle. | ||||
H. giebeli [16] | ||||||
Orthoptera sp. [16] | An indeterminate orthopteran. | |||||
Blattaria sp. [16] | An indeterminate cockroach. |
Anchisaurus is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Upper Portland Formation, Northeastern United States, which was deposited from the Hettangian age into the Sinemurian age, between about 200 and 192 million years ago. Until recently it was classed as a member of Prosauropoda. The genus name Anchisaurus comes from the Greek αγχιanchi-; "near, close" + Greek σαυρος ; "lizard". Anchisaurus was coined as a replacement name for "Amphisaurus", which was itself a replacement name for Hitchcock's "Megadactylus", both of which had already been used for other animals.
Podokesaurus is a genus of coelophysoid dinosaur that lived in what is now the eastern United States during the Early Jurassic Period. The first fossil was discovered by the geologist Mignon Talbot near Mount Holyoke, Massachusetts, in 1910. The specimen was fragmentary, preserving much of the body, limbs, and tail. In 1911, Talbot described and named the new genus and species Podokesaurus holyokensis based on it. The full name can be translated as "swift-footed lizard of Holyoke". This discovery made Talbot the first woman to find and describe a non-bird dinosaur. The holotype fossil was recognized as significant and was studied by other researchers, but was lost when the building it was kept in burned down in 1917; no unequivocal Podokesaurus specimens have since been discovered. It was made state dinosaur of Massachusetts in 2022.
Gigantoscelus is a dubious genus of basal sauropodomorph dinosaur from the Early Jurassic of South Africa.
The Newark Supergroup, also known as the Newark Group, is an assemblage of Upper Triassic and Lower Jurassic sedimentary and volcanic rocks which outcrop intermittently along the east coast of North America. They were deposited in a series of Triassic basins, the Eastern North American rift basins, approximately 220–190 million years ago. The basins are characterized as aborted rifts, with half-graben geometry, developing parallel to the main rift of the Atlantic Ocean which formed as North America began to separate from Africa. Exposures of the Newark Supergroup extend from South Carolina north to Nova Scotia. Related basins are also found underwater in the Bay of Fundy. The group is named for the city of Newark, New Jersey.
The Forest Sandstone is a geological formation in southern Africa, dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages of the Jurassic Period in the Mesozoic Era. As its name suggests, it consists mainly of sandstone.
Dinosaur Footprints in Holyoke, Massachusetts, USA is an 8-acre (3 ha) wilderness reservation purchased for the public in 1935 by The Trustees of Reservations. The Reservation is currently being managed with the assistance from the Massachusetts Department of Conservation and Recreation (DCR). The fossil and plant resources on the adjacent Holyoke Gas and Electric (HG&E) riverfront property are being managed cooperatively by The Trustees, Mass DCR, and HG&E.
The Elliot Formation is a geological formation and forms part of the Stormberg Group, the uppermost geological group that comprises the greater Karoo Supergroup. Outcrops of the Elliot Formation have been found in the northern Eastern Cape, southern Free State, and in the eastern KwaZulu-Natal provinces of South Africa. Outcrops and exposures are also found in several localities in Lesotho such as Qacha's Neck, Hill Top, Quthing, and near the capital, Maseru. The Elliot Formation is further divided into the lower (LEF) and upper (UEF) Elliot formations to differentiate significant sedimentological differences between these layers. The LEF is dominantly Late Triassic (Norian-Hettangian) in age while the UEF is mainly Early Jurassic (Sinemurian-Pliensbachian) and is tentatively regarded to preserve a continental record of the Triassic-Jurassic boundary in southern Africa. This geological formation is named after the town of Elliot in the Eastern Cape, and its stratotype locality is located on the Barkly Pass, 9 km north of the town.
The Shuttle Meadow Formation is a Mesozoic geologic formation in the Hartford Basin in Connecticut and Massachusetts, USA. Insect fossils of Mormolucoides articulatus and dinosaur remains are among the fossils that have been recovered from the formation; Coelophysis sp.
The McCoy Brook Formation is a geological formation dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages. The McCoy Brook Formation is found in outcrops around the Bay of Fundy, Nova Scotia.
Stegomosuchus is an extinct genus of small protosuchian crocodyliform. It is known from a single incomplete specimen discovered in the late 19th century in Lower Jurassic rocks of south-central Massachusetts, United States. It was originally thought to be a species of Stegomus, an aetosaur, but was eventually shown to be related to Protosuchus and thus closer to the ancestry of crocodilians. Stegomosuchus is also regarded as a candidate for the maker of at least some of the tracks named Batrachopus in the Connecticut River Valley.
The Zagaje Formation is a Latest Triassic-Early Jurassic Epoch (Rhaetian-Sinemurian) geologic formation located mostly in Poland with layers also exposed in north Germany. This unit is known for its diverse Ichnofossil assemblages, with traces of invertebrates along vertebrate footprints, as well plants, large coal accumulations, invertebrate remains and ichnofossils. The Zagaje Formation correlates with The lower part of the Höganäs Formation in Scania, as well the Munkerup Member and the Gassum Formation in Denmark.
The Towaco Formation is a mapped bedrock unit in New Jersey. It is named for the unincorporated village of Towaco, which is near the place its type section was described by paleontologist Paul E. Olsen.
The Mecsek Coal Formation is a Jurassic geologic formation in Hungary. Indeterminate fossil ornithischian tracks have been reported from the formation.
The Feltville Formation is a mapped bedrock unit primarily in New Jersey, with one known outlier in Pennsylvania and another one in New York. It is named for the Deserted Village of Feltville in Watchung Reservation, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.
The East Berlin Formation is an Early Jurassic geological formation in New England, United States. Dinosaur footprints and trackways are abundant in this formation. These tracks include Eubrontes, Anchisauripus, and Anomoepus. Several museums, parks, and tourist attractions are based around the East Berlin Formation's dinosaur tracks, including Dinosaur State Park in Rocky Hill, Connecticut and Powder Hill Dinosaur Park in Middlefield, Connecticut.
The Boonton Formation is a mapped bedrock unit in New Jersey, formerly divided between the Boonton and Whitehall beds of the defunct Brunswick Formation. It is named for the town of Boonton, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.
The Stormberg Group is one of the four geological groups that comprises the Karoo Supergroup in South Africa. It is the uppermost geological group representing the final phase of preserved sedimentation of the Karoo Basin. The Stormberg Group rocks are considered to range between Lower Triassic (Olenekian) to Lower Jurassic (Pliensbachian) in age. These estimates are based on means of geological dating including stratigraphic position, lithostratigraphic and biostratigraphic correlations, and palynological analyses.
Paleontology in Massachusetts refers to paleontological research occurring within or conducted by people from the U.S. state of Massachusetts. The fossil record of Massachusetts is very similar to that of neighboring Connecticut. During the early part of the Paleozoic era, Massachusetts was covered by a warm shallow sea, where brachiopods and trilobites would come to live. No Carboniferous or Permian fossils are known from the state. During the Cretaceous period the area now occupied by the Elizabeth Islands and Martha's Vineyard were a coastal plain vegetated by flowers and pine trees at the edge of a shallow sea. No rocks are known of Paleogene or early Neogene age in the state, but during the Pleistocene evidence indicates that the state was subject to glacial activity and home to mastodons. The local fossil theropod footprints of Massachusetts may have been at least a partial inspiration for the Tuscarora legend of the Mosquito Monster or Great Mosquito in New York. Local fossils had already caught the attention of scientists by 1802 when dinosaur footprints were discovered in the state. Other notable discoveries include some of the first known fossil of primitive sauropodomorphs and Podokesaurus. Dinosaur tracks are the Massachusetts state fossil.
The Bull Run Formation is a Late Triassic (Norian) stratigraphic unit in the eastern United States. Fossil fish bones and scales have been found in outcrops of the formation's Groveton Member in Manassas National Battlefield Park. Indeterminate fossil ornithischian tracks have been reported from the formation.
The Midland Formation is a Mesozoic geological formation in the Culpeper Basin of Virginia. It is a sedimentary unit which formed in a short period of time between the first two basalt flows in the basin: the Hickory Grove and Mount Zion Church basalts. The most common rocks in the formation are dark reddish interbedded sandstones and siltstones, representative of fluvial (stream) environments. Rare but fossiliferous calcareous shale and limestone also occurs, representing recurring lacustrine (lake) conditions. The Midland Formation is considered equivalent to the Shuttle Meadow Formation of the Hartford Basin, the Feltville Formation of the Newark Basin, and the Bendersville Formation of the Gettysburg Basin. Some sources prefer to classify the Midland Formation as part of the Shuttle Meadow Formation.