Mass occurrences of articulated Jurassic echinoderms, containing high diversities at both species and class level are rare globally.
Whilst the UK Jurassic has spectacular and important echinoderm faunas, these are all known from multiple horizons, throughout relatively thick rock packages.
A new Bathonian (Middle Jurassic) site, found in 2020 by Neville and Sally Hollingworth, has produced an abundant, exquisitely preserved and diverse echinoderm fauna, from two horizons, separated by about 20cm, from a single, small locality in Wiltshire.
The new site exceeds all other British Middle Jurassic sites for diversity and abundance and is comparable to the best in the world, such as the Bajocian (Middle Jurassic) Schinznach site, near Basel, in the Swiss Jura (Hess 1972, 1973, 1999) although, again, this diversity and abundance is from multiple horizons within a relatively thick rock package. This exceptional site and the discovery story were broadcast widely by the world media in June 2021.
The unprecedented window these fossils provide on the evolution and diversity of echinoderms and other groups forms the focus of this project and how these in turn illuminate parts of the evolutionary history of major groups that are ecologically important today as well as the evolution of such modern ecosystems.
Of particular significance are the numerous exquisitely preserved comatulid and isocrinid (Class Crinoidea) fossils with regards to the evolution and early divergence and diversity of comatulid crinoids as well as insights into sea floor ecological tiering.
Aims
- Describe the diversity of Invertebrates and plants, particularly the echinoderms, microfossils and arthropods at this site.
- Elucidate the early diversity and radiation of comatulid crinoids based on data from the Wiltshire site and other Jurassic occurrences.
- Understand and describe the environment which supported large numbers of echinoderms in a relatively small space, and which led to their preservation.
- Understand the origins of tiered feeding in marine ecosystems.
Methods
- Field investigation of the geology and fossils at site.
- Standard bulk sampling and processing methods (sieving) for macro, meso and microfossils.
- Fossil preparation techniques (air abrasion, air pen and chemical immersion)
- Analysis and imaging of specimens using SEM and CT scanning, Light microscopy, photogrammetry and digital measurements.
- Quantify shape using a landmark free analysis employing the deformation fields technique of Toussaint et al., 2021.
Who is involved?
The large number of collaborators listed illustrates the multifaceted approach taken to thoroughly investigate this important site. The people involved bring a wealth of different knowledge of both taxonomy, analytical and preparatory work required to fully understand the significance. Other institutions involved:
· University Colledge London, UK
· Senckenberg Research Institute and Natural History Museum, Frankfurt, Germany
· Luxembourg National Museum of Natural History, Luxembourg
· Staatliches Naturhistorisches Museum, Braunschweig, Germany
· University of Southampton, UK
· University of Oxford, UK
· Diamond Light Source, Harwell, UK
The Natural History Museum's role
The museum plays a central role to this project because it houses the material being studied, the analytical and preparational facilities required to study the material as well as being the base of the lead investigator along with much of the diverse taxonomic expertise required.
