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

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

geological

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other English counties, functions have ...

, northern

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. Unlike the contemporaneous terrestrial Wealden Group 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 a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttl ...

and the lobster ''Meyeria ornata''.

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

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

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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

North Yorkshire North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of ...

Fossil content

The following fossils have been reported from the formation:Speeton Clay Formation
at Fossilworks.org * Reptiles ** Ichthyosaurs *** '' 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 reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became ...

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

Fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

** '' Cretorectolobus doylei''Underwood et al., 1999 ** '' "Dasyatis" speetonensis''Underwood et al., 1999 ** '' 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 a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s **

Crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

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

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

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

References

Bibliography

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Fossil content

See also

References

Bibliography

Further reading