Otter Sst Formation, Sidmouth-Ladram Bay (Triassic of the United Kingdom)

Where: England, United Kingdom (50.7° N, 3.3° W: paleocoordinates 13.4° N, 10.8° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Otter Sandstone Formation (Sherwood Sandstone Group), Anisian (247.2 - 242.0 Ma)

• late Anisian: "The unit is dated as Anisian on the basis of faunal comparisons and matching with palynologically dated units in the English Midlands... This has since been confirmed by magnetostratigraphy (Hounslow and McIntosh 2003), who found that the lower parts of the Otter Sandstone Formation correspond to the early and mid Anisian, and the upper parts, which contain the majority of the macrofossils correlate with late Anisian and latest Anisian magnetozones on the marine standard."

• formation-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; lithology not reported

• "The middle and upper parts of the formation are of fluvial origin; sandstones were deposited by ephemeral braided streams flowing from the south and south-west. The comparatively thin mudstones are interpreted as the deposits of temporary lakes on the floodplain. The calcretes indicate subaerial soil and subsurface calcrete formation in semi-arid conditions. The climate was semi-arid, with long periods when river beds dried out, and seasonal or occasional rains leading to violent river action and flash floods."

Size class: macrofossils

Collected by P. S. Spencer

Primary reference: A. R. Milner, B. G. Gardiner, N. C. Fraser and M. A. Taylor. 1990. Vertebrates from the Middle Triassic Otter Sandstone Formation of Devon. Palaeontology 33(4):873-892 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 88992: authorized by Richard Butler, entered by Richard Butler on 27.04.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Amphibia
 Temnospondyli -
Eocyclotosaurus sp. Ortlam 1970 tetrapod
EXEMS 60/1985.72, damaged posterior skull roof; EXEMS 60/1985.310, right tabular and parts of squamosal, supratemporal and postorbital
? Eocyclotosaurus sp. Ortlam 1970 tetrapod
EXEMS 60/1985.75, left clavicle
 Temnospondyli - Mastodonsauridae
Mastodonsauridae indet.2, "Mastodonsaurus lavisi" = Labyrinthodon lavisi
Mastodonsauridae indet.2 Lydekker 1885 tetrapod
EXEMS 60/1985.78, posterior right mandible
"Mastodonsaurus lavisi" = Labyrinthodon lavisi Seeley 1876 tetrapod
EXEMS 60/1985.287, left postfrontal and parietal; EXEMS 60/1985.309, left tabular and parts of squamosal and supratemporal
Amniota
  -
Amniota indet. amniote
EXEMS 60/1985.88, elongate bone, possibly a neural spine, suggested as a possible ctenosauriscid archosaur
Reptilia
 Diapsida - Tanystropheidae
cf. Tanystropheus sp. von Meyer 1852 archosauromorph
EXEMS 60/1985.143, tricuspid tooth
 Archosauria -
Archosauria indet.1 Cope 1869 archosaur
EXEMS 60/1985.291, 320, teeth; EXEMS 60/1986.8, dorsal vertebra; BRSUG 26206, dorsal vertebra; BRSUG 26207, 26212, teeth
Actinopteri
 Perleidiformes - Perleididae
Dipteronotus cyphus Egerton 1854
EXEMS 60/1985.293, 294