Complex sentence: Berothidae is very closely related to the thorny lacewings which are often included in the Berothidae as subfamily "Rhachiberothinae" but occasionally are considered the distinct family Rhachiberothidae or included as a subfamily in the mantidflies.
Split into simpler sentences: Berothidae is very closely related to the thorny lacewings which are often included in the Berothidae as subfamily "Rhachiberothinae". They are also occasionally considered to be the distinct family Rhachiberothidae or included as a subfamily in the mantidflies.