| Whitby Mudstone | |
| Type: | Geological formation |
| Age: | Toarcian (Falciferum-Bifrons) ~ |
| Period: | Toarcian |
| Prilithology: | Mudstone |
| Otherlithology: | Siltstone |
| Namedfor: | Whitby |
| Region: | Yorkshire, Worcestershire |
| Coordinates: | 54.5°N -0.6°W |
| Paleocoordinates: | 42.5°N 9.3°W |
| Unitof: | Lias Group |
| Subunits: | Members:
|
| Underlies: | Inferior Oolite or Ravenscar Groups Or Blea Wyke, Dogger or Bridport Sand Formations |
| Overlies: | Marlstone Rock or Cleveland Ironstone Formations |
| Thickness: | Up to 120m (390feet) |
| Extent: | Cleveland & Worcester Basins & East Midlands Shelf |
| Location Ts: | Coastal exposures from Hawsker Bottoms to Whitby Harbour |
The Whitby Mudstone is a Toarcian (Early Jurassic; Falciferum-Bifrons in regional chronostratigraphy) geological formation in Yorkshire and Worcestershire, England.[1] The formation, part of the Lias Group, is present in the Cleveland and Worcester Basins and the East Midlands Shelf.
The formation consists of mudstone and siltstone, partly laminated and bituminous, medium to dark grey in colour, with rare fine grained calcareous sandstone beds. Limestone and phosphatic nodules are present at some levels.[2]
Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.[3] [4] One of the more notable discoveries is the skull of the pterosaur Parapsicephalus, found within the Alum Shale Member.[5]
| Vertebrates of the Whitby Mudstone Formation | |||||||
|---|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Abundance | Notes | Images | |
| cf. Campylognathoides | Indeterminate | Winterton | Falciferum Zone | NHMUK PV R 36712, Humerus[6] | A pterosaur | ||
| Gyrosteus | G. mirabilis | Whitby | Multiple partial skeletons[7] | A large chondrosteid acipenseriform fish | |||
| Hauffiosaurus | H. longirostris | Whitby-Saltwick | Falciferum Zone | MCZ 1033, a skeleton | A Pliosaurid | ||
| Microcleidus | M. homalospondylus | Whitby | Upper Alum Shale, Hildoceras bifrons Zone | Multiple partial skeletons | Microcleidid plesiosaur | ||
| Macrospondylus | M. bollensis | Harpoceras serpentinum Zone | Several partial skeletons | Teleosaurid | |||
| Mystriosaurus | M. laurillardi | Whitby | Skull and lower jaws[8] | Teleosaurid, formerly considered to be the holotype of "Steneosaurus" brevior | |||
| Parapsicephalus | P. purdoni | Loftus Alum Shale Quarry, Saltwick Bay (referred material) | Upper Alum Shale Member | Single partial skull lacking the snout (GSM 3166), tentantive referral of a humerus and scapulocoracoid (NHMUK PV R36634).[9] | A Rhamphorhynchid pterosaur | ||
| Pelagosaurus | P. typus | Whitby | Alum Shale | Thalattosuchian | |||
| Rhomaleosaurus | R. thorntoni | Kingsthorpe Hollow | Upper | NHMUK PV Rr4853, a single mostly complete skeleton | A Rhomaleosaurid | ||
| R. zetlandicus | Loftus (also Lofthouse) Alum Mine | Alum Shale Member | YORYM G503, a partial skeleton[10] | ||||
| R. cramptoni | Alum quarry, Kettleness | NMING F8785, a partial skeleton | |||||
| Plagiophthalmosuchus | P. gracilirostris | Whitby | Teleosaurid | ||||
| ?Theropoda | Indeterminate | Femur, currently lost | |||||
| Tetanurae | Indeterminate | Incomplete anterior dorsal vertebra | Originally referred to Streptospondylus cuvieri. | ||||
Insect compression fossils are known from nodules found on Alderton Hill near Alderton and Dumbleton in Gloucestershire, including Alderton Hill Quarry and other nearby localities.[11]