Otter Sandstone Formation
| Otter Sandstone Formation (OS) | |
|---|---|
| Stratigraphic range: Anisian | |
| Exposures of Otter Sandstone at Ladram Bay, Devon, England | |
| Type | Formation | 
| Unit of | Sherwood Sandstone Group (SSG) | 
| Underlies | In coastal exposures, transitional into overlying Mercia Mudstone. | 
| Overlies | Budleigh Salterton Pebble Beds | 
| Thickness | Coast and Exeter district: ~160 m (520 ft) Taunton district: 30–60 m (98–197 ft) | 
| Location | |
| Region | England | 
| Country | United Kingdom | 
The Otter Sandstone Formation is an obsolete geological unit in England, now referred to as the Helsby Sandstone Formation. It preserves fossils dated to the Triassic, Anisian period.