Forest Marble Formation

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]

Forest Marble Formation
Stratigraphic range: Bathonian 168–164.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Forest Marble Formation exposed in Kirtlington Quarry, Oxfordshire
Type	Geological formation
Unit of	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
Lithology
Primary	Mudstone, Limestone
Other	Siltstone, Sandstone
Location
Region	Bedfordshire, Buckinghamshire, Oxfordshire, Dorset
Country	United Kingdom
Type section
Named for	Wychwood Forest

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

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

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

Saurischians

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Saurischians reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bothriospondylus[12]	B. robustus[10]	Wiltshire[10]		"Dorsal vertebra."[13]	Reassigned to Marmarospondylus	Cetiosaurus Proceratosaurus
	Indeterminate[8]	Oxfordshire[8]
Cardiodon[10]	C. rugulosus[10]	Wiltshire[10]
Cetiosaurus[14]	C. oxoniensis	Oxfordshire			A cetiosaurid sauropod.
"Cetiosaurus"	C. glymptonensis[8]	Oxfordshire[8]		"Caudal vertebrae."[15]	Actually indeterminate theropod remains.[16]
Dromaeosauridae[17]	Indeterminate[17]	Oxfordshire[17]	Kirtlington Quarry[17]	"Teeth"[17]	Remains represent three species. Same species also present in the Chipping Norton Limestone.[17] Other authors have questioned the attribution to dromaeosaurs.[18]
Marmarospondylus				Dorsal verebra	Dubious genus of sauropod
Megalosaurus[19]	M. bucklandii[16]	Gloucestershire[16]
	Indeterminate[20]	Dorset[21] Oxfordshire[8]			Actually indeterminate theropod remains.[20]
Proceratosaurus[16]	P. bradleyi[16]	Gloucestershire[16]			A proceratosaurid theropod. The geological formation that this species comes from is disputed, and other authors have attributed the strata to the White Limestone Formation.[22]

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.	Eodiscoglossus
Marmorerpeton	M. kermacki, M. freemani	Kirtlington, Watton Cliff			Neotenic stem-group salamander (Caudata) belonging to Karauridae
Caudata	Indeterminate	Kirtlington			2 distinct taxa, one common one small, referred to as Kirtlington Salamander A and B, respectively

Turtles

Turtles reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Paracryptodira[23]	Indeterminate	Kirtlington		Shell fragments, basisphenoid

Choristoderes

Choristoderes reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Cteniogenys	Indeterminate	Kirtlington			A small, lizard like choristoderan. Oldest record of the group

Pterosaurs

Choristoderes reported from the Forest Marble Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
"Rhamphorhynchoidea"	Indeteriminate	Kirtlington

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				Goniopholis
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	Morganucodon
Palaeoxonodon	P. ooliticus	Kirtlington, Watton Cliff			Amphitheriid
Paritatodon	P. kermacki	Kirtlington			Docodontan or Shuotheriidae
Peraiocynodon	P. major	Kirtlington			Docodontidae
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
Allotheria	Indeterminate	Kirtlington
Haramiyida	Indeterminate	Kirtlington
Dryolestida	Indeterminate			Lower molars
Peramuridae	Indeterminate	Watton Cliff

See also

• Earth sciences portal
• Paleontology portal
• Dinosaurs portal

• List of dinosaur-bearing rock formations
• Bradford Clay