The Speeton Clay Formation (SpC)Speeton Clay Formation
- BGS is a Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

geological formation in

Yorkshire Yorkshire ( ) is an area of Northern England which was History of Yorkshire, historically a county. Despite no longer being used for administration, Yorkshire retains a strong regional identity. The county was named after its county town, the ...

, northern

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. Unlike the contemporaneous terrestrial

Wealden Group The Wealden Group, occasionally also referred to as the Wealden Supergroup, is a group (stratigraphy), group (a sequence of rock strata) in the lithostratigraphy of southern England. The Wealden group consists of wiktionary:paralic, paralic to c ...

to the south, the Speeton Clay was deposited in marine conditions. The most common fossils in the unit are belemnites, followed by

ammonites Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

and the

lobster Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on th ...

''Meyeria ornata''.

Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

.Weishampel, et al. (2004)
"Dinosaur distribution."
pp. 517–607. The formation is named after the village of Speeton in

North Yorkshire North Yorkshire is a Ceremonial counties of England, ceremonial county in Northern England.The Unitary authorities of England, unitary authority areas of City of York, York and North Yorkshire (district), North Yorkshire are in Yorkshire and t ...

Fossil content

The following fossils have been reported from the formation:Speeton Clay Formation
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org *

Reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s **

Ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...

s *** '' Acamptonectes densus''Fischer et al., 2012bFischer et al., 2012a **

Neornithischia Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia. It is the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the insi ...

ns *** '' Owenodon hoggii''Norman & Barrett, 2002 *** Iguanodontia indet.Mulder & Fraaije, 2016 **

Sauropterygia Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic diapsid reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosau ...

ns ***

Elasmosauridae Elasmosauridae, often called elasmosaurs or elasmosaurids, is an extinct family of plesiosaurs that lived from the Hauterivian stage of the Early Cretaceous to the Maastrichtian stage of the Late Cretaceous period (c. 130 to 66 mya). The taxo ...

- "Speeton Clay plesiosaurian"Benson & Druckenmiller, 2014 *

Fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

** '' Cretorectolobus doylei''Underwood et al., 1999 ** '' "Dasyatis" speetonensis''Underwood et al., 1999 ** '' "Protosqualus. sp"' ** '' Notidanodon lanceolatus''Underwood et al., 1999 ** '' Notorhynchus aptiensis''Underwood et al., 1999 ** '' Synechodus dubrisiensis''Underwood et al., 1999 ** '' Spathobatis rugosus''Underwood et al., 1999 ** '' ?Sphenodus sp.''Underwood et al., 1999 ** '' "Elops" neocomiensis''Underwood et al., 1999 ** Pycnodontidae indet.Underwood et al., 1999 ** Semionotidae indet.Underwood et al., 1999 ** Teleostei indet.Underwood et al., 1999 ** ?Triakidae indet.Underwood et al., 1999 *

Invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s **

Crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s *** '' Martillepas auriculum''Gale, 2019 **

Crinoid Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are ...

s *** Crinoidea indet.Underwood et al., 1999

References

Bibliography

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Fossil content

See also

References

Bibliography

Further reading