Microvertebrates from the classic Rhaetian bone beds of Manor Farm Quarry, near Aust (Bristol, UK)

Abstract

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Pseudocetorhinus pickfordi, absent in the basal bone bed, are relatively abundant in the four overlying bone-bearing units. These differences in faunal lists and in relative proportions probably do not reflect sampling, but some major differences in ecology and evolution.

The first discovery of crinoids and cephalopod hooklets in the British Triassic

“…This also suggests that a higher diversity of organisms was present in the seas that deposited the Blue Anchor Formation than those of the upper Westbury Formation, but this may be a bias in the data -neither Br.co.08-3 nor Parkway 3 samples the basal Westbury Formation bone bed, which has proven the richest in previous studies (e.g. Swift and Martill, 1999;Allard et al, 2015).…”

“…Swift and Martill, 1999;Allard et al, 2015;Korneisel et al, 2015;Nordén et al, 2015;Lakin et al, 2016), but elements of the accompanying invertebrate fauna are less well known. In particular, as Swift (1999, p. 180) noted, 'Cephalopods are almost unknown from the Penarth Group'.…”

The Rhaetian (Late Triassic) vertebrates of Hampstead Farm Quarry, Gloucestershire, UK

“…Vallisia coppi teeth are small (1.5 mm high) with three upright to slightly inclined cusps that are flattened labio-lingually ( These highly distinctive teeth have also been described from the Rhaetian of Vallis and Holwell, both in Somerset (Duffin, 1982), Manor Farm Quarry (Allard et al, 2015) and Belgium (Duffin et al, 1983). The most recent taxonomic consideration of V. coppi places it in the Neoselachii incertae sedis (Cappetta, 2012, p. 327).…”

“…Because of the generally conservative nature of the postcranial elements of these marine reptiles, however, they generally cannot be assigned to genera. Other reptile components common in the bone beds of the Westbury Formation are vertebrae and long bones of the early choristodere (or thalattosaur) Pachystropheus rhaeticus (Storrs, 1994;Swift and Martill, 1999;Allard et al, 2015).…”

“…Pachystropheus is an enigmatic reptile, classified variously as a choristodere or a thalattosaur (Storrs and Gower, 1993;Storrs et al, 1996;Renesto, 2005;Allard et al, 2015), and common in certain Rhaetian bone beds, but especially those where there has been modest physical transport and abrasion (Storrs, 1994(Storrs, , 1999Trueman and Benton 1997;Allard et al, 2015).…”