The Chilonycterinae are the most primitive of the subfamilies of the Phyllostomatidae. Two basic groups comprise this subfamily: the first includes the genera Pteronotus and Chilonycteris; the second, the genus Mormoops. This grouping is based principally upon the characteristics of the humerus and the innominate. Within the subfamily Phyllostomatinae two types are recognized. The Macrotus-type is considered the more primitive, because of its resemblance to the chilonycterines, and the Phyllustomus-type the more advanced. From these two phyllostomatine groups are derived the more advanced lines of the Phyllostomatidae. The phyllonycterine line appears to be derived from the Macrotus-type. The sturnirine-glossophagine line and the stenodcrmine line are derived from the Phyllostomus-type. The Vam pyrops-type of stenodermine shows affinities with the glossophagines and is considered the more primitive stenodermine. The Artibrns-type stenodermine is considered the more advanced. The carolline group shows relationships to the Macrotus-type of phyllostomatine and also shows affinities with the sturnirines. A more thorough study of the genera involved is needed to determine this relationship. The family Phyllostomatidae has its closest affinities with the Desmodontidae, and post-cranial evidence offers little reason to consider these as separate families. Other close relationships of the Phyllostomatidae appear to exist with the Noctilionidae and possibly with the Emballonuridae
