Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea) Author Jong, Rienk De text Zootaxa 2017 4270 1 1 63 journal article 32975 10.5281/zenodo.583183 6c479acc-8b18-4f0b-a6e5-85bcd6d7b6b7 1175-5326 583183 2D00AFF5-4FE2-4EC1-A328-C8670CFB8D6D libytheoides . Stolopsyche libytheoides Scudder, 1889 Family incertae sedis. USA , Colorado , Teller County , Florissant; late Priabonian, late Eocene. Depository: MCZH (holotype, no.11077). Published figures: Scudder (1889: Pl. LIII Figs. 1–3 ) ; Emmel et al . (1992 : Fig. 4 /1); Murata (1998: Figs. 42, 43) . This specimen is poorly preserved; according to Zeuner (1961) this fossil is too poor for attempting an assignment to a particular family. Antennae with very gradually thickened club, which takes about 1/3 of the whole antennal length. If not for this character, the fossil could as well represent a non-papilionoid lepidopteran. Forelegs long, only a little shorter than middle legs. This is a plesiomorphic character found in Papilionidae , Pieridae , Lycaenidae females, Libythea females, and Hesperiidae . It could place the fossil in the ancestry of any butterfly family. Since the head is small for Hesperiidae and Libythea , the forewing is long for Lycaenidae (ca. 25 mm ), and the palps long for Papilionidae, Scudder thought the Pieridae the most likely family for the fossil. Apparently the fossil has too few characters preserved to be of any use for phylogenetic research. I cannot find any evidence supporting the claim by Emmel et al . (1992) that the fossil “was closer to Pieris than any other living genus.” Apparently, Braby et al . (2006) based their use of this fossil as calibration point in the phylogenetic tree of Pieridae close to the origin of Pieris on the unsupported assumption of Emmel et al . (1992) (l.c.)—an unwarranted and probably erroneous assumption.