The fossil macrurous Crustacean Glyphea from within Thalassinoides burrows in the Inferior Oolite Formation of Frogden Quarry, Oborne, Dorset, UK

Crustaceans occur within Thalassinoides burrow systems in the Upper Bajocian, Inferior Oolite Formation of Oborne, Dorset. This is only the fourth record from the Jurassic worldwide, the first record from rocks between the Lower Jurassic, Toarcian and Upper Jurassic, Bathonian stages, and the third record from any rocks in the British Isles. The Sherborne Building Stone Beds of Frogden Quarry in Dorset were deposited over the very short time interval of only one ammonite faunal horizon, possibly as little as 30,000 years. This was probably due to flow of sediments into a forming graben. During this time there were episodes of slower sedimentation which allowed the formation of extensive Thalassinoides burrow systems at several horizons. From within, and outside, these burrows we have found remains of the macrurous crustacean Glyphea regleyana Desmarest. The evidence suggests that these were the burrow makers which were probably overwhelmed by sediment flows.