Spine Banks var addthis_config = {"data_track_addressbar":true};

Spine Banks are a Tyranid biomorph made of rows of spines embedded in cavities in the carapace of a Tyranid creature which are fired by muscle contraction at close ranges. This showers an area with spines covered with poison which easily incapacitate and distract nearby enemies.¹ Spine Banks often form the Frag Spines studded along some Carnifexes.²

Sources

• ¹: Codex: Tyranids (4th Edition), p.33
• ²: Codex: Tyranids (5th Edition), p.46