A pack of 5 small bags of Echinoiderm spines (Cidarids) from the Devonian rocks of the Moroccan Atlas mountains. Some are complete, others not, but these are excellent teaching material to show how sea urchins would have protected themselves with this spines that stuck out from their body shell. Without them they would be very vulnerable. Up to 35mm in size. Typical sample of 5 bags are shown in the picture, spines are around 2.5cm in length at their largest. You get loads for a little price.