Taynton Limestone Formation

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 predominanty 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.

Taynton Limestone Stratigraphic range: Bathonian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Great Oolite Group
Underlies	Hampen Formation, Rutland Formation
Overlies	Fuller's Earth Formation, Sharp's Hill Formation, Horsehay Sand Formation
Thickness	0-11 m
Lithology
Primary	Limestone
Other	Marl, Sandstone
Location
Region	Oxfordshire
Country	England
Type section
Named for	Taynton, Oxfordshire
Location	Lee's Quarry, Taynton Down, Oxfordshire

Vertebrate fauna

Reptiles

Reptiles of the Stonesfield Slate[5]
Taxa	Species	Material	Location	Notes	Images
Iliosuchus	I. incognitus	Two ilia		Not distingusiable from Megalosaurus
Megalosaurus	M. bucklandii	Isolated remains including several dentaries, maxillas and postcranial bones from multiple individuals		A Megalosaurid, 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			A Teleosaurid

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

Invertebrate fauna

Invertebrates of the Stonesfield Slate
Taxa	Presence	Notes	Images
Genus: Blapsium	Geographically present at Stonesfield.[8]

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 noticeably different assembelage than the Yorkshire floras of equivalent age, possibly because the latter is thought to represent a deltaic, wetland environment[9]

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
Pachyptermis	P. macrophylla			Member of Peltaspermales
Komlopteris	K. speciosa			Member of Peltaspermales
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

See also

• List of dinosaur-bearing rock formations

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. "Stonesfield Slate quarries". paleobiodb.org. Retrieved 2019-10-05.
6. 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. United States Congressional Serial Set. U.S. Government Printing Office. 1892-01-01.
9. 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.