Diplocynodon hantoniensis Nicholson and Lydekker

Barton Beds (now the Barton Group) is the name given to a series of grey and brown

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

s, with layers of

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

, of Upper

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

age (around 40 million years old), which are found in the

Hampshire Basin The Hampshire Basin is a geological basin of Palaeogene age in southern England, underlying parts of Hampshire, the Isle of Wight, Dorset, and Sussex. Like the London Basin to the northeast, it is filled with sands and clays of Paleocene and ...

of southern England. They are particularly well exposed in the

cliff In geography and geology, a cliff or rock face is an area of Rock (geology), rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. ...

s at

Barton-on-Sea Barton on Sea (often hyphenated as Barton-on-Sea) is a cliff-top village in Hampshire, England close to the town of New Milton to the north. Barton lies within the civil parish of New Milton. As a settlement, Barton has a history dating back to ...

, which is the type locality for the Barton Beds, and lends its name to the Bartonian age of the Eocene

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

. The clay is abundant in

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s, especially

molluscs Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

. The beds are found in the

, and are well exposed in the cliffs of Barton, Hordle, and on the

Isle of Wight The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...

.Archibald Geikie, (1903), ''Text-book of Geology, Volume 2'', page 1233. The cliffs at Barton are the world type locality for the Barton Beds.Janet M. Hooke, (1998), ''Coastal Defence and Earth Science Conservation'', pages 246-7. Geological Society. The beds consist of grey, greenish and brown

s with bands of

and have long been well known for the abundance and excellent preservation of their fossils. More than 500 species have been recorded,Charles Panzetta Chatwin, (1960), ''British Regional Geology: the Hampshire Basin and adjoining areas'', page 68. Geological Survey of Great Britain of which, over half are

, including numerous turret shells and lamellibranchs.Derrick Knowlton, (1973), ''The Naturalist in Central Southern England: Hampshire, Berkshire, Wiltshire, Dorset and Somerset'', page 51. David & Charles Sharks teeth are common, and the beds have yielded remains of

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

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 ...

es,

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

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, and

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s. Plant fossils are also abundant. In the 1840s fossils were found in the "crocodile bed" at Hordle cliff, which belonged to an extinct species of alligator, which was subsequently named '' Diplocynodon hantoniensis'', after the county of

Hampshire Hampshire (, ; abbreviated to Hants.) is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Berkshire to the north, Surrey and West Sussex to the east, the Isle of Wight across the Solent to the south, ...

(''Hantonia'' being a Latinization based on the Anglo-Saxon name ''Hantescire''). Above the highly

fossiliferous A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved i ...

Barton Clay, there is a sandy series with few

s; these are the Headon Hill or Barton Sands. Today, the Barton Beds are rather poorly exposed in many sections due to coastal protection works.P. J. Brenchley, Peter Franklin Rawson, (2006), ''The geology of England and Wales'', page 423 The ''Barton Beds'' are of Upper

age, and the area was covered with an inland sea, and the temperature was higher than at the present day. The term "

Bartonian The Bartonian is, in the International Commission on Stratigraphy's (ICS) geologic time scale, a stage or age in the middle of the Eocene Epoch or Series. The Bartonian Age spans the time between . It is preceded by the Lutetian and is follow ...

" was introduced by

Karl Mayer-Eymar Karl David Wilhelm Mayer-Eymar (29 July 1826 – 25 February 1907) was a Franco-Swiss paleontologist and geologist known for his work on classifying the stratigraphy of the Tertiary into 12 stages. He was born Karl Mayer but added the anagram Eyma ...

in 1857 for the

continental Continental may refer to: Places * Continental, Arizona, a small community in Pima County, Arizona, US * Continental, Ohio, a small town in Putnam County, US Arts and entertainment * ''Continental'' (album), an album by Saint Etienne * Continen ...

equivalents of the series.

References

{{Reflist, refs= {{EB1911, inline=1, first=John Allen, last=Howe, wstitle=Barton Beds, volume=3, page=453 This cites: * "Geology of the Isle of Wight," ''Mem. Geol. Survey'' (2nd ed., 1889) * "The Geology of the Country around Southampton," ''Mem. Geol. Survey'' (1902).

External links

''Barton and Highcliffe, Eocene Strata''
''Geology of the Wessex Coast of southern England'', by Ian West Sediments Paleogene England Geologic formations of England Lithostratigraphy of England