Micrina is an extinct genus of tommotiids with affinities to brachiopods.

[1] Micrina can be considered a stem group brachiopod based on its larval shell.

[2] Its microstructure is very brachiopod like[3] and its adult morphology is similarly bivalved,[4] even though it was once thought to be halkieriid-like.

[5] Micrina is quite similar to Mickwitzia in terms of shell microstructure.

The two genera are evidently closely related.