Magnesian Conglomerate | |
---|---|
Stratigraphic range: Rhaetian ~ | |
Type | Geological formation, fissure fill |
Underlies | none |
Overlies | Friars Point Limestone Formation? |
Lithology | |
Primary | Breccia |
Other | Limestone |
Location | |
Coordinates | 51°30′N2°36′W / 51.5°N 2.6°W |
Approximate paleocoordinates | 35°54′N0°48′E / 35.9°N 0.8°E |
Region | South West England & South Wales |
Country | England |
Extent | Bristol |
Type section | |
Named by | Henry Riley & Samuel Stutchbury |
Year defined | 1836 |
The Magnesian Conglomerate is a geological formation in Clifton, Bristol in England (originally Avon), Gloucestershire and southern Wales, present in Tytherington, Durdham Down, Slickstones Quarry and Cromhall Quarry.
It dates back to the Rhaetian stage of the Late Triassic, [1] [2] although it may be as old as the Norian stage of the Late Triassic and as young as the Hettangian stage of the Early Jurassic.[ citation needed ]
The Magnesian Conglomerate was first discovered in autumn 1834 and was studied in 1836 by Henry Riley and Samuel Stutchbury. [3]
The Avon Fissure Fill is often paired with the Magnesian Conglomerate. [1]
Taxon | Species | Presence | Notes | Images |
---|---|---|---|---|
Actinopteri [4] | Indeterminate [4] | Geographically present in Durdham Down. [4] | A tooth. [4] | |
Agnosphitys [2] [5] | A. cromhallensis [2] [5] | Geographically present in Avon, England (now Bristol). [2] | Its remains include a left ilium (holotype) and a left maxilla, astragalus and humerus (referred specimen). [2] | |
Agrosaurus [6] [2] | A. macgillivrayi [6] [2] | Geographically present in Avon, England (now Bristol). Originally believed to have been found in Cape York Peninsula, Queensland (Australia). [2] | A tibia, a claw and some other fragments. [2] | |
Archosauria [7] | Indeterminate [7] | Geographically present in Durdham Down. [4] | Five specimens, including jaw fragments, caudals, and a scapulocoracoid. [7] | |
Archosauromorpha [4] | Indeterminate [4] | Geographically present in Durdham Down. [4] | A fragment of a small tooth. [4] | |
Asylosaurus [2] [8] | A. yalensis [2] [8] | Geographically present in Avon, England (now Bristol). [2] [9] | Dorsal vertebrae, ribs, gastralia, a shoulder girdle, humeri, a partial forearm, and a hand; additional bones from the neck, tail, pelvis, arm and legs that may represent the same individual. [8] [2] | |
Chimaeriformes [10] | Indeterminate [10] | Geographically present in Bristol. [2] | Indeterminate remains. [10] | |
Clevosaurus [11] | C. hudsoni [11] | Geographically present in Gloucestershire. [2] | Partial cranial and post-cranial skeleton (holotype). [11] | |
Crinoidea [10] | Indeterminate [10] | Geographically present in Bristol. [2] | Reworked from older Carboniferous sediments (Friars Point Limestone Formation). [12] | |
Cryptovaranoides [13] | C. microlanius [14] | Geographically present in Slickstones Quarry. [15] | Holotype (partial skeleton) and referred isolated remains. [16] | |
Diphydontosaurus [10] | D. avonensis [10] | Geographically present in Bristol. [2] | Complete to near-complete specimens. [10] | |
Herrerasauria? [8] | Indeterminate [8] | Geographically present in Durdham Down. [4] | 3 indeterminate specimens. [8] | |
Hwiccewyrm [17] | H. trispiculum [17] | Geographically present in Slickstones Quarry. [17] | Several specimens comprising a partial skeleton. [17] Discovered during the 1970s and listed as cf. Hypsognathus by Whiteside et al. (2016). [18] | |
Hybodontiformes? [4] | Indeterminate [4] | Geographically present in Bristol. [2] | Indeterminate remains. [4] | |
Gyrolepis [19] | Indeterminate [19] | Geographically present in Bristol. [2] | Indeterminate remains. [19] | |
Kuehneosauridae [4] | Indeterminate [4] | Geographically present in Durdham Down. [4] | Rib that may instead be an ulna belonging to Terrestrisuchus . [4] | |
Lissodus [4] | L. minimus [4] | Geographically present in Bristol. [2] | Teeth. [4] | |
Ornithischia [8] | Indeterminate [8] | Geographically present in Durdham Down. [4] | Indeterminate specimen. [8] | |
Palaeosaurus [2] [8] | P. cylindrodon [2] [8] | Geographically present in Avon, England (now Bristol) and Bristol. [2] | Two teeth (one destroyed in 1940). [2] | |
Phytosauria [4] | Indeterminate [4] | Geographically present in Durdham Down. [4] | Two teeth previously assigned to Mystriosuchinae. [4] | |
Planocephalosaurus [20] [21] | P. robinsonae [20] [21] | Geographically present in Bristol. [2] | Skull (holotype) and a tooth. [20] | |
Plateosauria [22] | Indeterminate [22] | Geographically present in Durdham Down. [4] | 22 partial specimens. [22] | |
Rhomphaiodon [4] | R. minor [4] | Geographically present in Bristol. [2] | Teeth, including the subsidiary cusp of one tooth. [4] | |
Rileyasuchus [2] [23] [24] | R. bristolensis [2] [23] [24] | Geographically present in Bristol. [2] | Two vertebrae and a humerus. [2] | |
Sauropodomorpha [8] | Indeterminate [8] | Geographically present in Durdham Down. [4] | Indeterminate remains. [8] | |
Sphenosuchia [4] | Indeterminate [4] | Geographically present in Durdham Down. [4] | A right femur initially named as Thecodontosaurus costa. [4] | |
Terrestrisuchus [4] [10] | T. gracilis and indeterminate [4] [10] | Geographically present in Bristol and South Wales. [2] | Indeterminate and partial remains. [4] [10] | |
Theropoda [2] | Indeterminate [2] | Geographically present in Avon, England (now Bristol) and Bristol. [2] | A tooth, and a tibia that was once allied with Thecodontosaurus . [2] [8] Possibly similar to Pendraig milnerae . [25] | |
Thecodontosaurus [2] | T. antiquus [2] | Geographically present in Avon, England (now Bristol) and Bristol. [2] | Partial cranial and postcranial remains (holotype is a lower jaw). [2] |
Squamata is the largest order of reptiles, comprising lizards and snakes. With over 11,500 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Members of the order are distinguished by their skins, which bear horny scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. Squamates are the most variably sized living reptiles, ranging from the 16 mm (0.63 in) dwarf gecko to the 6.5 m (21 ft) reticulated python. The now-extinct mosasaurs reached lengths over 14 m (46 ft).
Thecodontosaurus is a genus of herbivorous basal sauropodomorph dinosaur that lived during the late Triassic period.
Agrosaurus is an extinct genus of thecodontosaurid sauropodomorph probably originating from the Magnesian Conglomerate of England that was originally believed to be a Triassic prosauropod from Australia. Agrosaurus would thus be the oldest dinosaur from that country. However, this appears to have been an error, and the material actually appears to come from Thecodontosaurus or a Thecodontosaurus-like animal from Bristol, England. The type species is Agrosaurus macgillivrayi.
Palaeosaurus is a genus of indeterminate archosaur known from two teeth found in the Bromsgrove Sandstone Formation and also either the Magnesian Conglomerate or the Avon Fissure Fill of Clifton, Bristol, England. It has had a convoluted taxonomic history.
Sphenosaurus is a poorly known genus of procolophonid, a type of prehistoric reptile from the Late Permian Buntsanstein of Germany. Originally assigned the name Palaeosaurus sternbergii, by German paleontologist Leopold Joseph Fitzinger in 1840, the generic name was already preoccupied by not one but two other reptiles assigned the name Palaeosaurus. In 1847, Hermann von Meyer recognized the original 1833 and 1836 usages of Palaeosaurus and moved P. sternbergii to a new genus, Sphenosaurus.
Hypsognathus is an extinct genus of procolophonid parareptile from the Late Triassic of New Jersey, Connecticut, and Nova Scotia.
Planocephalosaurus is an extinct genus of basal rhynchocephalian. Fossils of the genus are primarily known from fissure fill deposits from the Late Triassic of southwest Britain, with fragmentary remains possibly belonging to the genus also known from the Late Triassic of Texas.
Terrestrisuchus is an extinct genus of very small early crocodylomorph that was about 76 centimetres (30 in) long. Fossils have been found in Wales and Southern England and date from near the very end of the Late Triassic during the Rhaetian, and it is known by type and only known species T. gracilis. Terrestrisuchus was a long-legged, active predator that lived entirely on land, unlike modern crocodilians. It inhabited a chain of tropical, low-lying islands that made up southern Britain, along with similarly small-sized dinosaurs and abundant rhynchocephalians. Numerous fossils of Terrestrisuchus are known from fissures in limestone karst which made up the islands it lived on, which formed caverns and sinkholes that preserved the remains of Terrestrisuchus and other island-living reptiles.
Slickstones Quarry, Cromhall, also known as Cromhall Quarry, is a 2.7 hectare geological Site of Special Scientific Interest near the village of Cromhall, South Gloucestershire, England notified in 1966.
Thecodontosauridae is a family of basal sauropodomorph dinosaurs that are part of the Bagualosauria, known from fossil remains found exclusively in the Magnesian Conglomerate of Bristol, England, which dates back to the Rhaetian stage of the Late Triassic. Two genera are known: Agrosaurus and Thecodontosaurus; the former is often considered to be the same animal as the latter.
The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to Varanus and Anguis than Scincus. These lizards, along with iguanians and snakes, constitute the proposed "venom clade" Toxicofera of all venomous reptiles.
Asylosaurus is a genus of basal sauropodomorph dinosaur from the Late Triassic Avon Fissure Fill of England. It is based on partial remains, discovered in the autumn of 1834, described in 1836 by Henry Riley and Samuel Stutchbury as pertaining to Thecodontosaurus, that Othniel Charles Marsh brought to Yale University between 1888 and 1890. These remains thus escaped destruction by a bombardment in 1940 during World War II, unlike the original holotype of Thecodontosaurus. Asylosaurus was described in 2007 by Peter Galton. The type species is A. yalensis, referring to Yale. The bones originally came from a Rhaetian-age cave fill at Durdham Down, Clifton, Bristol.
Clevosaurus is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods. Species of Clevosaurus were widespread across Pangaea, and have been found on all continents except Australia and Antarctica. Five species of Clevosaurus have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, C. hadroprodon is the oldest record of a sphenodontian from Gondwana, though its affinity to Clevosaurus has been questioned.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1836.
Diphydontosaurus is an extinct genus of small rhynchocephalian reptile from the Late Triassic of Europe. It is the most primitive known member of Sphenodontia.
The Avon Fissure Fill, also known as the Bristol Fissure Fill or Tytherington Fissure Fill, is a fissure fill in Avon, England which dates variously from the Norian and Rhaetian stages of the Late Triassic, or possibly as late as the Hettangian stage of the Early Jurassic. The fissure fill at Avon was a sinkhole formed by the dissolution of Lower Carboniferous limestones.
Henry Riley (1797–1848) was a British surgeon, anatomist, naturalist, geologist and paleontologist. He is notable for being the co-discoverer and co-describer of the archosaur Palaeosaurus and the dinosaur Thecodontosaurus.
Rhomphaiodon is an extinct genus of prehistoric sharks in the order Synechodontiformes that has been found in Late Triassic and Early Jurassic deposits located in Europe. The type species R. minor was originally named as a species of Hybodus in 1837 by Louis Agassiz. A second species, R. nicolensis, was added when the genus was named in 1993.
Cryptovaranoides is an extinct genus of reptile from the Late Triassic Magnesian Conglomerate of England. It contains a single species, Cryptovaranoides microlanius.
Hwiccewyrm is an extinct genus of leptopleuronine procolophonid parareptile from the Late Triassic Magnesian Conglomerate of England. The type, and currently only, species is H. trispiculum.