Taynton Limestone Formation Explained

Taynton Limestone
Type:Geological formation
Period:Bathonian
Prilithology:Limestone
Otherlithology:Marl, Sandstone
Namedfor:Taynton, Oxfordshire
Region:Oxfordshire
Unitof:Great Oolite Group
Underlies:Hampen Formation, Rutland Formation
Overlies:Fuller's Earth Formation, Sharp's Hill Formation, Horsehay Sand Formation
Thickness:0-11 m
Location Ts:Lee'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
TaxaSpeciesMaterialLocationNotesImages
IliosuchusI. incognitusTwo iliaA theropod dinosaur. Not distingusiable from Megalosaurus
MegalosaurusM. bucklandiiIsolated remains including several dentaries, maxillas and postcranial bones from multiple individualsA megalosaurid theropod dinosaur, also present in the Chipping Norton and Sharp's Hill Formations
Klobiodon[5] K. rocheiPartial dentary with teethA rhamphorhynchid pterosaur
ProtochelysP. blakiiIsolated epidermal scales, coracoid, plastron fragment[6] Nomen dubium, Testudinata indet
Teleosaurus T. geoffroyiAn indeterminate Teleosaurid. Probably the same animal as Teleosaurus cadomensis.
MonofenestrataIndeterminateVertebrae
IndeterminateVarious isolated remains

Mammaliamorphs

Mammaliamorphs of the Stonesfield Slate[7]
TaxaSpeciesMaterialLocationNotesImages
AmphilestesA. broderipiiTwo left mandibles and right mandibleStonesfield Slate quarriesAmphilestid
AmphitheriumA. prevostiiPartial left mandible and a right mandibleAmphitheriidae
A. rixoniRight dentary
StereognathusS. ooliticusTeethTritylodontid
PhascolotheriumP. bucklandiiRight mandible and left ramusAmphilestid

Fish

Fish of the Stonesfield Slate
TaxaSpeciesMaterialLocationNotesImages
BreviacanthusBreviacanthus brevisStonesfield Slate quarries
GanodusSpp.
Ischyodus Ischyodus emarginatus
Aspidorhynchus Aspidorhynchus crassus
PholidophorusIndeterminate
Leptolepis Leptolepis disjectus
Pycnodus Indeterminate
MesodonMesodon tenuidens
MicrodonMicrodon biserialis
LepidotusLepidotus tuberculatus
MacrosemiusMacrosemius sp.
UndinaUndina ? barroviensisA coelacanth
CeratodusCeratodus phillipsiA lungfish
Egertonodus[8] Egertonodus duffiniA hybodont shark
Palaeocarcharias?[9] IndeterminatePossibly the oldest lamniform shark

Invertebrate fauna

Invertebrates of the Stonesfield Slate
TaxaSpeciesPresenceMaterialNotesImages
BlapsiumB. egertoni Stonesfield SlateNHM, In. 34379, a ventral compression missing the headAn ommatine beetle
PalaeontinaP. ooliticaForewingType species of Palaeontinidae
PheugothemisP. westwoodiDamsel-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
TaxaSpeciesMaterialLocationNotesImages
cf. DictyophyllumIndeterminateFern, Member of Dipteridaceae
PhlebopterisP. woodwardiiFern, Member of Matoniaceae
cf. ConiopterisIndeterminateFern, Member of Dicksoniaceae
SagenopterisS. colpodesMember of Caytoniales
Ctenozamitescf. leckenbyiMember of Peltaspermales
PachypterisP. macrophyllaA "Pteridosperm", likely either a member of Peltaspermales or Corystospermales
KomlopterisK. speciosaMember of Corystospermales
CtenisC. cf. sulcicaulis, spCycad
PtilophyllumP. pectiniformis, P. cf hirsutumMember of Bennettitales
SphenozamitesS. belliiMember of Bennettitales
?WeltrichiaIndeterminateMember of Bennettitales
TaeniopterisT. vittataMember of Bennettitales
BucklandiaB. bucklandiiMember of Bennettitales formerly Conites bucklandii[11]
GinkgoG. aff longifoliusMember of Ginkgoales
BrachyphyllumB. expansumMember of Pinales
Elatocladus E. cf. laxusMember of Pinales
MasculostrobusIndeterminateMember of Pinales
ClassostrobusIndeterminateCheirolepidiaceae
Araucarites A. brodeiAraucariaceae
Pelourdea A conifer of uncetain affinities
CarpolithesCarpolithes diospyriformis, Carpolithes sp.Plantae indet
Phyllitessp.Morphotaxon for leaves of uncertain affinities

See also

References

Notes and 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. .
  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,
  3. Web site: Taynton Limestone Formation. BGS Lexicon of Named Rock Units. 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. 10.1016/S0016-7878(08)80014-4. 1993PrGA..104..123B .
  5. 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.
  6. 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.
  7. Web site: Stonesfield Slate, near Oxford (BMNH fish). 17 December 2021. fossilworks.org.
  8. Rees . Jan . Underwood . Charlie J. . January 2008 . Hybodont Sharks of the English Bathonian and Callovian (Middle Jurassic) . Palaeontology . en . 51 . 1 . 117–147 . 10.1111/j.1475-4983.2007.00737.x . 0031-0239. free . 2008Palgy..51..117R .
  9. Underwood . Charlie J. . Ward . David J. . May 2004 . Neoselachian sharks and rays from the British Bathonian (Middle Jurassic) . Palaeontology . en . 47 . 3 . 447–501 . 10.1111/j.0031-0239.2004.00386.x . 0031-0239. free . 2004Palgy..47..447U .
  10. Cleal. C. J.. Rees. P. M.. July 2003. The Middle Jurassic flora from Stonesfield, Oxfordshire, UK. Palaeontology. 46. 4. 739–801. 10.1111/1475-4983.00319. 0031-0239. free. 2003Palgy..46..739C .
  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. 10.1002/tax.615033. 0040-0262. free.