This class of ascomycete fungi is mainly defined by its DNA sequence. Penicillium and Aspergillus are familiar members of this group. There are 2 types of sexual fruiting bodies:
- perithecia, often covered with sharp spines, which have an opening from which the ascospores are released, or
- cleistothecia and related structures which are typically completely closed and the ascospores are released when these structures break open or are opened by animals.
The Eurotiomycetes are divided into 2 subclasses, depending on the above structures of their fruiting bodies, the Chaetothyriomycetidae and the Eurotiomycetidae.
The following orders are here included: