| Noun | 1. | class Anthoceropsida - hornworts: in some classification systems included in the class Hepaticopsida class - (biology) a taxonomic group containing one or more orders Bryophyta, division Bryophyta - a division of nonflowering plants characterized by rhizoids rather than true roots and having little or no organized vascular tissue and showing alternation of generations between gamete-bearing forms and spore-bearing forms; comprises true mosses (Bryopsida) and liverworts (Hepaticopsida) and hornworts (Anthoceropsida) Anthocerotales, order Anthocerotales - hornworts; liverworts having a thalloid gametophyte; in some classification systems included in the class Hepaticopsida Anthocerotaceae, family Anthocerotaceae - hornworts |