Taynton Limestone
Stratigraphic range: Bathonian
↓
TypeGeological formation
Unit ofGreat Oolite Group
UnderliesHampen Formation, Rutland Formation
OverliesFuller's Earth Formation, Sharp's Hill Formation, Horsehay Sand Formation
Thickness0-11 m
Lithology
PrimaryLimestone
OtherMarl, Sandstone
Location
RegionOxfordshire
Country England
Type section
Named forTaynton, Oxfordshire
LocationLee's Quarry, Taynton Down, Oxfordshire

The Taynton Limestone[1] is a geological formation in Oxfordshire in the United Kingdom. It dates to the Middle Jurassic, mid-Bathonian stage.[2] It predominantly consists of ooidal grainstone.[3] The term "Stonesfield Slate" refers to slaty limestone horizons within the formation that during the 18th and 19th centuries were extensively quarried for use in roof tiling within the vicinity of Stonesfield, Oxfordshire. Previously these were thought to belong to the Sharp's Hill Formation, but boreholes and shaft sections suggest that at least three horizons within the Taynton Limestone were quarried for the slate.[4] These horizons are well known for producing a diverse set of fossils including those of plants, insects as well as vertebrates, including some of the earliest known mammals, pterosaurs as well as those of first dinosaur ever described, Megalosaurus.

Vertebrate fauna

Reptiles

Reptiles of the Stonesfield Slate[5]
Taxa Species Material Location Notes Images
Iliosuchus I. incognitus Two ilia A theropod dinosaur. Not distingusiable from Megalosaurus
Megalosaurus M. bucklandii Isolated remains including several dentaries, maxillas and postcranial bones from multiple individuals A megalosaurid theropod dinosaur, also present in the Chipping Norton and Sharp's Hill Formations
Klobiodon[6] K. rochei Partial dentary with teeth A rhamphorhynchid pterosaur
Protochelys P. blakii Isolated epidermal scales, coracoid, plastron fragment[7] Nomen dubium, Testudinata indet
Teleosaurus T. geoffroyi An indeterminate Teleosaurid. Probably the same animal as Teleosaurus cadomensis.
Monofenestrata[6] Indeterminate Vertebrae
Rhamphorhynchidae[6] Indeterminate Various isolated remains

Mammaliamorphs

Mammaliamorphs of the Stonesfield Slate[5]
Taxa Species Material Location Notes Images
Amphilestes A. broderipii Two left mandibles and right mandible Stonesfield Slate quarries Amphilestid
Amphitherium A. prevostii Partial left mandible and a right mandible Amphitheriidae
A. rixoni Right dentary
Stereognathus S. ooliticus Teeth Tritylodontid
Phascolotherium P. bucklandii Right mandible and left ramus Amphilestid

Fish

Fish of the Stonesfield Slate[5]
Taxa Species Material Location Notes Images
Breviacanthus Breviacanthus brevis Stonesfield Slate quarries
Ganodus Spp. Chimaeriformes
Ischyodus Ischyodus emarginatus
Aspidorhynchus Aspidorhynchus crassus
Pholidophorus Indeterminate
Leptolepis Leptolepis disjectus
Pycnodus Indeterminate
Mesodon Mesodon tenuidens
Microdon Microdon biserialis
Lepidotus Lepidotus tuberculatus
Macrosemius Macrosemius sp.
Undina Undina ? barroviensis A coelacanth
Ceratodus Ceratodus phillipsi A lungfish
Egertonodus[8] Egertonodus duffini A hybodont shark
Palaeocarcharias?[9] Indeterminate Possibly the oldest lamniform shark

Invertebrate fauna

Invertebrates of the Stonesfield Slate
Taxa Species Presence Material Notes Images

Blapsium

B. egertoni Stonesfield Slate NHM, In. 34379, a ventral compression missing the head An ommatine beetle
Palaeontina P. oolitica Forewing Type species of Palaeontinidae
Pheugothemis P. westwoodi Damsel-dragonfly of uncertain placement, while historically described as a member of Gomphidae, Huang et al. 2019 state that it "can[not] be accurately attributed to the Gomphidae, or even the Gomphida."

Flora

The flora known from the Stonesfield Slate comprises a relatively diverse flora, with 25 morphospecies present. It primarily represents a coastal environment, perhaps seasonally dry with mangrove like environments. It is a noticeably different assemblage than the Yorkshire floras of equivalent age, possibly because the latter is thought to represent a deltaic, wetland environment.[10]

Flora of the Stonesfield Slate
Taxa Species Material Location Notes Images
cf. Dictyophyllum Indeterminate Fern, Member of Dipteridaceae
Phlebopteris P. woodwardii Fern, Member of Matoniaceae
cf. Coniopteris Indeterminate Fern, Member of Dicksoniaceae
Sagenopteris S. colpodes Member of Caytoniales
Ctenozamites cf. leckenbyi Member of Peltaspermales
Pachypteris P. macrophylla A "Pteridosperm", likely either a member of Peltaspermales or Corystospermales
Komlopteris K. speciosa Member of Corystospermales
Ctenis C. cf. sulcicaulis, sp Cycad
Ptilophyllum P. pectiniformis, P. cf hirsutum Member of Bennettitales
Sphenozamites S. bellii Member of Bennettitales
?Weltrichia Indeterminate Member of Bennettitales
Taeniopteris T. vittata Member of Bennettitales
Bucklandia B. bucklandii Member of Bennettitales formerly Conites bucklandii[11]
Ginkgo G. aff longifolius Member of Ginkgoales
Brachyphyllum B. expansum Member of Pinales
Elatocladus E. cf. laxus Member of Pinales
Masculostrobus Indeterminate Member of Pinales
Classostrobus Indeterminate Cheirolepidiaceae
Araucarites A. brodei Araucariaceae
Pelourdea A conifer of uncetain affinities
Carpolithes Carpolithes diospyriformis, Carpolithes sp. Plantae indet
Phyllites sp. Morphotaxon for leaves of uncertain affinities

See also

References

  1. ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 538–541. ISBN 0-520-24209-2.
  2. ^ Benson, R.B.J. (2009). "An assessment of variability in theropod dinosaur remains from the Bathonian (Middle Jurassic) of Stonesfield and New Park Quarry, UK and taxonomic implications for Megalosaurus bucklandii and Iliosuchus incognitus." Palaeontology, doi:10.1111/j.1475-4983.2009.00884.x
  3. ^ "Taynton Limestone Formation". BGS Lexicon of Named Rock Units. Retrieved 2019-09-21.
  4. ^ Boneham, B.F.W.; Wyatt, R.J. (January 1993). "The stratigraphical position of the Middle Jurassic (Bathonian) Stonesfield Slate of Stonesfield, Oxfordshire, UK". Proceedings of the Geologists' Association. 104 (2): 123–136. doi:10.1016/S0016-7878(08)80014-4.
  5. ^ a b c "Stonesfield Slate, near Oxford (BMNH fish)". fossilworks.org. Retrieved 17 December 2021.
  6. ^ a b c Michael O’Sullivan; David M. Martill (2018). "Pterosauria of the Great Oolite Group (Bathonian, Middle Jurassic) of Oxfordshire and Gloucestershire, England". Acta Palaeontologica Polonica. Online edition. doi:10.4202/app.00490.2018.
  7. ^ Anquetin, Jérémy; Claude, Julien (2008). "Reassessment of the oldest British turtle: Protochelys from the Middle Jurassic Stonesfield Slate of Stonesfield, Oxfordshire, UK". Geodiversitas. 30 (2): 331–344.
  8. ^ Rees, Jan; Underwood, Charlie J. (January 2008). "Hybodont Sharks of the English Bathonian and Callovian (Middle Jurassic)". Palaeontology. 51 (1): 117–147. doi:10.1111/j.1475-4983.2007.00737.x. ISSN 0031-0239.
  9. ^ Underwood, Charlie J.; Ward, David J. (May 2004). "Neoselachian sharks and rays from the British Bathonian (Middle Jurassic)". Palaeontology. 47 (3): 447–501. doi:10.1111/j.0031-0239.2004.00386.x. ISSN 0031-0239.
  10. ^ Cleal, C. J.; Rees, P. M. (July 2003). "The Middle Jurassic flora from Stonesfield, Oxfordshire, UK". Palaeontology. 46 (4): 739–801. doi:10.1111/1475-4983.00319. ISSN 0031-0239.
  11. ^ Doweld, Alexander B. (October 2012). "(2099) Proposal to conserve the name Bucklandia Brongn. against Bucklandia Sternb. and Conites (fossil Gymnospermae , Cycadeoideopsida )". Taxon. 61 (5): 1131–1132. doi:10.1002/tax.615033. ISSN 0040-0262.
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