1. Thyriothecia lacking a distinct layer at the base, biotrophs and saprobes on leaves and stems	2
1. Thyriothecia with a distinct peridium layer at the base, growing on lichens and other fungi	Trichothyriaceae
2. Thyriothecia with a distinct central rounded ostiole	3. “Microthyriales”
2. Thyriothecia lacking a distinct rounded ostiole, but upper wall cracking, dissolving or dehiscing to form a linear or star-like or irregular central ostiole or gelatinous opening	4.
3. Thyriothecia with a distinct darkened, circular central ostiole, upper wall comprising neatly arranged parallel cells, asci narrowly obclavate to long fusiform, ascospores one septate, hyaline, with or without appendages or with cilia at the ends	Microthyriaceae
3. Thyriothecia with a central circular ostiole, lacking a darkened rim, blue green blue black to black, upper wall comprising non radiate, flattened, often meandrous interwoven cells, asci clavate to cylindrical or elongate, asci developing inclined towards the center of thyriothecia, ascospores trans-septate, usually with more than two septa	Micropeltidaceae
4. Thyriothecia opening with an irregular pore or starlike dehiscence or dissolving to form a gelatinous mass, asci globose to saccate, ascus surface may blue in IKI Asterinales (consider Asterinaceae and Palmulariaceae)
4. Thyriothecia opening with a slit-like pore, ascus surface not bluing in IKI	Aulographaceae