£2.00 – £4.00
• Geological Age: Jurassic period, Lower Lias, 200 to 174 million years ago.
• Location: Hook Cliff, Gloucestershire, Yorkshire, UK.
• Family: Bivalve
• Species: Gryphaea arcuata
Gryphea Arcuata are a common bivalve fossil and as such, these specimens are often used for educational purposes. These samples come from Hook Cliff in Yorkshire and are roughly 6 cm in length, found in Jurassic strata, they are 200 to 174 million years old and are of high quality, showing such morphological features as growth lines, hinges and more. A dull grey colour, they are suitable for collectors as well of fine quality specimens.
Gryphaea arcuata are an extinct species of oyster which lived during the early part of the Jurassic period, making these fossil specimens 200 to 174 million years old. Samples of them can be found through out Europe as well as many other sub species belonging to this group. They are a common find around coastal parts of the UK and are often referred to as 'Devils Toe Nails' due to their toe nail like appearance yet, unsightly coiled and twisted shape. As expected of a bivalve, the shell is made up of two unequal parts, the top and bottom, the bottom being smaller. It has been inferred that the arcuata sub-species is roughly in the middle of the evolutionary line of gryphaea, with a moderate size and elongated shell, where as later species' shells appeared to be more wider and flat. These high quality samples will enable you to see many morphological features of the fossil in depth, even without use of magnification, such as the line between the two shells, the hinge and growth lines. We have numerous sized specimens available: small are supplied in 2"x2" card trays, Medium in 3"x2" card trays and Large in 3"x3" card trays. They are excellent fossils for serious collectors or educational use. Supplied in a card tray with an information label.