Microvertebrates from the Rhaetian bone beds at the Carrefour site, Patchway, near Bristol

The Carrefour site at Patchway, north of Bristol, reveals an exposure of the Westbury Formation, including two Rhaetian bone beds. This is the first published report of the microvertebrate assemblage of this locality, following excavations and observations in 1977, 2024, and 2025. As usual, the species Lissodus minimus and Gyrolepis albertii are abundant, but the location is significant as a source of rare species including the sharks Parascylloides turnerae and Pseudodalatias barnstonensis and the marine reptile Pachystropheus rhaeticus . The two bone beds differ in composition, showing a switch from chondrichthyan to osteichthyan dominated faunas. They differ also taphonomically, in degree of abrasion, colouration and chemical composition, confirming that the upper bone bed cannot have been reworked from the lower bone bed, as previously suggested for other localities. There is evidence for water deepening through the Westbury Formation record, as expected with advance of the Rhaetian Transgression through time. We re-assess cephalopod hooklets reported earlier from the Westbury Formation and conclude that these, and new specimens from the Carrefour site, are probably clasper denticles of the shark Pseudodalatias .