Asteroid
Ordovician (Ashgillian)
Drumwick Group – Starfish beds
Threave Glen, Girvan, Scotland.

Two starfish, 9mm and 8mm on 45mm slab with small brachiopod.

Echinoderm. Association.

Tetraster is a genus of starfish known from the Ordovician of Scotland and is also one of the early members of the group.

Starfish are generally uncommon as fossils because they tend to disintegrate quickly after death, but in some rock layers where conditions allowed, they can be found in good numbers – deposits where rapid burial occurred to seal them in sediment. Most fossil starfish are missing the ends of their arms or even entire arms.

Here are two near-complete specimens with a brachiopod in matrix – an interesting association piece.