Bivalves are aquatic molluscs commonly found in the fossil record and still thrive in the seas and beaches of the modern day. They have paired shells with a line of symmetry running through the middle of these shells. Bivalves are the most common fossils found on the Jurassic Yorkshire coast. They first appeared in the Cambrian (~520 mya), though were far less common than today. The Carboniferous rocks of the Peak District and Yorkshire Dales are the source of many of our specimens, with some of our collection expanding as far as France, Australia and Madagascar.
Cardinia gigantea with Pleurotomaria sp. (gastropod) collected from Redcar
Brachiopods occupy seabed environments which range from tropical to arctic climates. They have a pair of shells with an opening at the umbo (base) of the pedicle valve (larger shell), allowing a pedicle (stalk like muscle) to attach to seafloor. However, not all brachiopods have these pedicle openings. All brachiopods have a plane of symmetry through the mid-plane of the shell. The entirety of our brachiopod specimenrs were collected from within England. These animals originated in the lower Cambrian and survive to this day, though in a much reduced diversity than their peak.