A similar (though broader) category is miospores, a term generally used for spores smaller than 200 μm.
[1] Cryptospores are generally found in non-marine rocks and decrease in abundance with distance offshore.
[2] Recently, fossils of plant sporangia have been found in Oman with cryptospores showing concentric lamellae in their walls, similar to liverworts.
[3] Spores from the Lindegård Mudstone (late Katian–early Hirnantian) represent the earliest record of early land plant spores from Sweden and possibly also from Baltica and implies that land plants had migrated to the palaeocontinent Baltica by at least the Late Ordovician.
[4] This discovery reinforces the earlier suggestion that the migration of land plants from northern Gondwana to Baltica in the Late Ordovician was facilitated by the northward migration of Avalonia,[5] which is evidenced by the co-occurrence of reworked, Early–Middle Ordovician acritarchs, possibly suggesting an Avalonian provenance in a foreland basin system.