Hedylidae, the "American moth-butterflies", is a family of insects in the order Lepidoptera, representing the superfamily Hedyloidea. They have traditionally been viewed as an extant sister group of the butterfly superfamily Papilionoidea, but a 2014 phylogenetic analyses has suggested Hedylidae is a subgroup of Papilionoidea, and not a sister group, and are more accurately referred to as butterflies rather than moths. They are represented by a single Neotropical genus Macrosoma with 35 currently recognized species.
Hedylidae were previously treated as a tribe of Geometridae: Oenochrominae, the "Hedylicae". Prout considered they might even merit treatment as their own family. Scoble first considered them to be a hitherto unrecognised group of butterflies and also suggested Hedylidae might possibly constitute the sister group of the "true" butterflies (Papilionoidea), rather than of (Hesperioidea + Papilionoidea). Weintraub and Miller argued against this placement (but see). In 1995, Weller and Pashley found that molecular data did indeed place Hedylidae with the butterflies and a more comprehensive study in 2005 based on 57 exemplar taxa, three genes and 99 morphological characters, recovered the genus Macrosoma as sister to the ("Papilionoidea" + Hesperioidea). However, the most recent phylogenetic analyses shows that skippers are true butterflies and therefore within the clade Papilionoidea, whereas the hedylids are a sister group that may be closely related to the obtectomeran moths. This is contrary to some earlier studies that had shown both the skippers and hedylids as being nested within the Papilionoidea.
Since there are no obvious gaps between supposed species groups, according to basic morphological structure, Scoble (1986) synonymised the five pre-existing genera of Hedylidae (33 of which had been described in Phellinodes) into the single genus Macrosoma. However, a phylogenetic analysis of all Macrosoma species is still needed.