Forest Marble Formation Explained

Forest Marble Formation
Type:	Geological formation
Period:	Bathonian
Prilithology:	Mudstone, Limestone
Otherlithology:	Siltstone, Sandstone
Namedfor:	Wychwood Forest
Region:	Bedfordshire, Buckinghamshire, Oxfordshire, Dorset
Unitof:	Great Oolite Group
Underlies:	Cornbrash Formation
Overlies:	White Limestone Formation, Athelstan Oolite Formation, Chalfield Oolite Formation, Corsham Limestone Formation, Frome Clay
Thickness:	Up to 5m thick in Buckinghamshire, 10 to 30m in Oxfordshire and Gloucestershire, 30 to about 50m in north Dorset, 30 to 75m in south Dorset

The Forest Marble is a geological formation in England. Part of the Great Oolite Group, it dates to the late Bathonian stage of the Middle Jurassic.^[1]

Lithology

The primary lithology of the formation typically consists of greenish grey variably calcareous silicate mudstone, with lenticular cross bedded limestone units deposited in a marine setting.^[2]

Paleobiota

Despite the formation being nearly entirely marine, at several localities abundant remains of terrestrial microvertebrates are found, the primary locality being the Kirtlington Mammal Bed (designated 3p) in Kirtlington Quarry near Kirtlington, Oxfordshire.^[3] Another important locality is Watton Cliff near Eype in Dorset.^[4]

Fish

Fish of the Forest Marble Formation^[5]
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Hybodus	Hybodus obtusus	Watton Cliff			A hybodont shark
Egertonodus	Egertonodus duffini
Secarodus	Secarodus polyprion
Strophodus	Spp.				A hybodont shark, formerly considered to be Asteracanthus
Lonchidion	Indeterminate				A hybodont shark
Parvodus	Parvodus pattersoni
Lissodus	Lissodus leiopleurus
Palaeocarcharias?^[6]	Indeterminate				Possibly the oldest lamniform shark

Dinosaurs

Ornithischians

Ornithischians of the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Alocodon^[7]	Indeterminate	Oxfordshire
Hylaeosaurus^[8]	Indeterminate	Wiltshire^[9]			Dubious
Iguanodon^[10]	Indeterminate	Oxfordshire^[11]			Dubious, probably indeterminate ornithischian

Saurischians

Saurischians reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bothriospondylus^[12]	B. robustus	Wiltshire		"Dorsal vertebra."^[13]	Reassigned to Marmarospondylus
	Indeterminate	Oxfordshire
Cardiodon	C. rugulosus	Wiltshire
Cetiosaurus^[14]	C. oxoniensis	Oxfordshire			A cetiosaurid sauropod.
"Cetiosaurus"	C. glymptonensis	Oxfordshire		"Caudal vertebrae."^[15]	Actually indeterminate theropod remains.
Dromaeosauridae^[16]	Indeterminate	Oxfordshire	Kirtlington Quarry	"Teeth"	Remains represent three species. Same species also present in the Chipping Norton Limestone. Other authors have questioned the attribution to dromaeosaurs.^[17]
Marmarospondylus				Dorsal verebra	Dubious genus of sauropod
Megalosaurus^[18]	M. bucklandii^[19]	Gloucestershire
	Indeterminate^[20]	Dorset^[21] Oxfordshire			Actually indeterminate theropod remains.

Amphibians

Amphibians reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Anoualerpeton	A. priscus	Kirtlington			Albanerpetontid
Eodiscoglossus	E. oxoniensis	Kirtlington			Frog, probably not closely related to type species of genus.
Marmorerpeton	M. kermacki, M. freemani	Kirtlington, Watton Cliff			Neotenic stem-group salamander (Caudata) belonging to Karauridae
	Indeterminate	Kirtlington			2 distinct taxa, one common one small, referred to as Kirtlington Salamander A and B, respectively

Lepidosauromorphs

Lepidosauromorphs reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Balnealacerta	B. silvestris	Kirtlington			Scincomorph lizard
Bellairsia	B. gracillis	Kirtlington			Squamate
Eophis	E. underwoodi	Kirtlington			Stem-snake
Marmoretta	M. oxoniensis	Kirtlington			Basal Lepidosauromorph
Oxiella	O. tenuis	Kirtlington			Squamate
Parviraptor	cf. estesi	Kirtlington			Stem-snake
Saurillodon	S. marmorensis	Kirtlington			Paramacellodid lizard
Rhynchocephalia	Indeterminate	Kirtlington

Crocodyliformes

Crocodyliformes reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
cf. Goniopholis	Indeterminate	Kirtlington
cf. Theriosuchus	Indeterminate	Kirtlington

Mammaliamorphs

Mammaliamorphs reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Amphitherium	Indeterminate	?Kirtlington, Watton Cliff			The first Mesozoic mammal to be described. Initially believed to be a marsupial. Close relative of Palaeoxonodon and Peramuridae.
Borealestes	B. serendipitus	Kirtlington, Watton Cliff		molar fragments	Docodonta
Dobunnodon	B. mussetti	Kirtlington		molar fragments
Gobiconodon	G. bathoniensis	Kirtlington, Watton Cliff			Gobiconodontid
Hahnotherium	H. antiquum	Kirtlington, Watton Cliff			Multituberculate
Kermackodon	K. multicuspis, K. oxfordensis	Kirtlington, Watton Cliff			Allotherian belonging to the family Kermackodontidae, K. oxfordensis previously placed in separate genus Eleutherodon.
Kirtlingtonia	K. catenata	Kirtlington			Haramiyid
Krusatodon	K. kirtlingtonensis	Kirtlington			Tegotheriid docodontan
Millsodon	M. superstes	Kirtlington, Watton Cliff			Haramiyid
Morganucodon	M. tardus	Watton Cliff			Morganucodontidae
Palaeoxonodon	P. ooliticus	Kirtlington, Watton Cliff			Amphitheriid
Paritatodon	P. kermacki	Kirtlington			Docodontan or Shuotheriidae
Peraiocynodon	P. major	Kirtlington
Phascolotherium	P. simpsoni	Kirtlington, Watton Cliff			Amphilestidae
Simpsonodon	S. oxfordensis	Kirtlington			Docodonta
Shuotherium	Indeterminate	Kirtington			Shuotheriidae
Stereognathus	S. ooliticus	Kirtlington, Watton Cliff			Tritylodontidae
Stylidens	S. hookeri	Watton Cliff			Morganucodontidae
Wareolestes	W. rex	Kirtlington			Morganucodonta
	Indeterminate	Kirtlington
	Indeterminate	Kirtlington
Dryolestida	Indeterminate			Lower molars
	Indeterminate	Watton Cliff

See also

• List of dinosaur-bearing rock formations
• Bradford Clay

References

• Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. .

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. Web site: Forest Marble Formation . . BGS Lexicon of Named Rock Units . 1 November 2018.
3. Web site: Kirtlington 3p (Mammal Bed) . 28 August 2018 . Paleobiology Database .
4. Web site: Watton Cliff (West Cliff), Dorset . 28 August 2018 . Paleobiology Database .
5. 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.
6. 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.
7. Listed as "cf. Alocodon sp." in "10.11 Oxfordshire, England; 6. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
8. Listed as "?Hylaeosaurus sp." in "10.13 Wiltshire, England; 3. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
9. "10.13 Wiltshire, England; 3. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
10. Listed as "?Iguanodon sp." in "10.11 Oxfordshire, England; 6. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
11. "10.11 Oxfordshire, England; 6. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
12. "10.11 Oxfordshire, England; 6. Forest Marble Formation" and "10.13 Wiltshire, England; 3. Forest Marble Formation," in Weishampel, et al. (2004). Page 540.
13. "Table 13.1," in Weishampel, et al. (2004). Page 270.
14. "10.11 Oxfordshire, England; 6. Forest Marble Formation," in Weishampel, et al. (2004). Page 538, 540.
15. "Table 13.1," in Weishampel, et al. (2004). Page 265.
16. Wills . S. . Underwood . C. J. . Barrett . P. M. . 2023 . Machine learning confirms new records of maniraptoran theropods in Middle Jurassic UK microvertebrate faunas . Papers in Palaeontology . 9 . 2 . e1487 . 10.1002/spp2.1487. free .
17. Yu . Yilun . Yi . Hongyu . Wang . Shiying . Pei . Rui . Zhang . Chi . Xu . Xing . December 1, 2023 . A Jurassic Tibetan theropod tooth reveals dental convergency and its implication for identifying fragmentary fossils . The Innovation Geoscience . en . 1 . 3 . 100040–10 . 10.59717/j.xinn-geo.2023.100040 . 2959-8753. free .
18. Weishampel, et al. (2004). Pages 539-540.
19. "10.3 Gloucestershire, England; 4. Forest Marble Formation," in Weishampel, et al. (2004). Page 538.
20. "10.7 Dorset, England; 2. Forest Marble Formation" and "10.11 Oxfordshire, England; 6. Forest Marble Formation," in Weishampel, et al. (2004). Pages 539-540.
21. "10.7 Dorset, England; 2. Forest Marble Formation," in Weishampel, et al. (2004). Page 539.
22. Scheyer. Torsten M.. Anquetin. Jérémy. March 2008. Bone histology of the Middle Jurassic turtle shell remains from Kirtlington, Oxfordshire, England. Lethaia. 41. 1. 85–96. 10.1111/j.1502-3931.2007.00044.x. 0024-1164.