Systematics

Leucippus baeri is monotypic.

Described as Leucippus Baeri Simon 1901; type locality Tumbes, Perú

Phylogenetic analysis of DNA sequence data reveals that hummingbirds (Trochilidae) constitute nine major clades, comprising the hermits, mangos, Patagona, topazes, coquettes, brilliants, mountain-gems, bees, and emeralds (McGuire et al. 2009, 2014). Leucippus is a member of the emerald clade; other genera in this radiation include Cynanthus, Chlorostilbon, Cyanophaia, Hylocharis, Campylopterus, Klais, Abeillia, Orthorhynchus, Stephanoxis, Anthocephala, Microchera, Elvira, Goethalsia, Goldmania, Thalurania, Eupherusa, Chalybura, Phaeochroa, Taphrospilus, Eupetomena, Aphantochroa, Trochilus, Amazilia, Lepidopyga, Chrysuronia, Juliamyia, and Chlorestes (McGuire et al. 2009, 2014). Many genera in the emerald clade, including Leucippus, are not monophyletic (McGuire et al. 2009, 2014). Leucippus baeri is sister to Leucippus taczanowskii (Spot-throated Hummingbird); these two species belong to a small clade that also includes Taphrospilus hypostictus (Many-spotted Hummingbird), Eupetomena macroura (Swallow-tailed Hummingbird), and Aphantochroa cirrochloris (Sombre Hummingbird) (McGuire et al. 2014). The type species of Leucippus is fallax (Buffy Hummingbird), which belongs to a different clade. Consequently, baeri and taczanowskii will need to be classified in a different genus, perhaps Thaumasius Sclater 1879 (type species Thaumasius taczanowksii = "Leucippus" taczanowskii).