Thornback Ray Spine

  This next find is one which has taken me a really long time to identify. At first I thought it was a bent safety pin, for a while I thought it was a whistling acacia seed from Africa, then I thought it was an animal claw, and finally I saw it had been identified on the London Mudlark facebook page. And I am so happy it was. Because it turns out it's much cooler! It's a Thornback Ray spine.

Mudlarking find: Thornback Ray spine

  Thornback Rays are widespread in coastal waters from Iceland to Norway. Its geographic ranges extends into the North Sea, The Meditteranean Sea, the Black Sea, Madeira Island, the Atlantic coasts of Africa, as well as the waters off the coast of South Africa and the South-Western Indian Ocean.
They inhabit a range of sea floor habitats, including mud, sand, gravel, and rocky areas.

Map of Thornback Ray territory

 As the name denotes, the upper portion of the body and tail are covered with thorn-like projections. When Thornback Rays reach sexual maturity the bases of the thorns thicken to resemble small button like projections called buckler. The snout and small portions of the body are covered in thorns in sub adults and the underside may be thorny in large females. Adults typically have between 21 and 25 large thorns running from the nape to its first pectoral fin.

Thornback Ray photo with detail of spines similar to my find

  The largest specimen ever recorded weighed 18 kg. Females can grow up to 130 cm long and live to 12 years of age. 

Thornback Ray Raja Clavata diagram

Images from Sharktrust and animaldiversity.org