Systematics

Within its extremely limited range, there is no known geographic variation in plumage characteristics.

Gray-bellied Comet is the sole member of Taphrolesbia. The relationships of Taphrolesbia to other genera of hummingbirds long was uncertain, but some authors suggested that it probably was most closely related to Polyonymus and Sappho (3 Züchner, T. (1999) Grey-bellied Comet Taphrolesbia griseiventris. Page 656 in Handbook of the birds of the world. Volume 5 (J. del Hoyo, A. Elliott, and J. Sargatal, Editors). Lynx Edicions, Barcelona. Close ), two other genera of long tailed hummingbirds that occur in relatively dry montane scrub. Phylogenetic analysis of DNA sequence data, however, indicates instead that Taphrolesbia is sister to Aglaiocercus (4 McGuire, J. A., C. C. Witt, J. V. Remsen, Jr., A. Corl, D. L. Rabosky, D. L. Altshuler, and R. Dudley (2014). Molecular phylogenetics and the diversification of hummingbirds. Current Biology 24:910–916. Close ; see also 5 Kirchman, J. J., C. C. Witt, J. A. McGuire, and G. R. Graves (2010) DNA from a 100-year old holotype confirms the validity of a potentially extinct hummingbird species. Biology Letters 6: 112–115. Close and 6 Pérez-Emán, J. L., J. Perdigón Ferreira, N. Gutiérrez-Pinto, A. M. Cuervo, L. N. Céspedes, C. C. Witt, and C. D. Cadena (2018). An extinct hummingbird species that never was: a cautionary tale about sampling issues in molecular phylogenetics. Zootaxa 4442(3):491–497. Close , all of which rely on the same sample of Taphrolesbia). Aglaiocercus is yet another genus of long-tailed Andean hummingbird, but it occupies humid montane forest and forest edges.

These same phylogenetic data reveal that hummingbirds constitute nine major clades, comprising the hermits, mangos, Patagona, topazes, coquettes, brilliants, mountain-gems, bees, and emeralds (7 McGuire, J. A., C. C. Witt, J. V. Remsen Jr., R. Dudley, and D. L. Altshuler (2009). A higher-level taxonomy for hummingbirds. Journal of Ornithology 150(1):155–165. Close , 4 McGuire, J. A., C. C. Witt, J. V. Remsen, Jr., A. Corl, D. L. Rabosky, D. L. Altshuler, and R. Dudley (2014). Molecular phylogenetics and the diversification of hummingbirds. Current Biology 24:910–916. Close ). Taphrolesbia and Aglaiocercus are members of the coquette clade (7 McGuire, J. A., C. C. Witt, J. V. Remsen Jr., R. Dudley, and D. L. Altshuler (2009). A higher-level taxonomy for hummingbirds. Journal of Ornithology 150(1):155–165. Close , 4 McGuire, J. A., C. C. Witt, J. V. Remsen, Jr., A. Corl, D. L. Rabosky, D. L. Altshuler, and R. Dudley (2014). Molecular phylogenetics and the diversification of hummingbirds. Current Biology 24:910–916. Close ). Other genera that belong to the coquette clade are Adelomyia, Chalcostigma, Discosura, Heliangelus, Lesbia, Lophornis, Metallura, Opisthoprora, Oreonympha, Oreotrochilus, Oxypogon, Phlogophilus, Polyonymus, Ramphomicron, Sappho, and Sephanoides (7 McGuire, J. A., C. C. Witt, J. V. Remsen Jr., R. Dudley, and D. L. Altshuler (2009). A higher-level taxonomy for hummingbirds. Journal of Ornithology 150(1):155–165. Close , 4 McGuire, J. A., C. C. Witt, J. V. Remsen, Jr., A. Corl, D. L. Rabosky, D. L. Altshuler, and R. Dudley (2014). Molecular phylogenetics and the diversification of hummingbirds. Current Biology 24:910–916. Close ).

Cynanthus griseiventris Taczanowski 1883 (8 Taczanowski, L. (1883) Description des espèces nouvelles de la collection péruvienne de M. le Dr. Raimondi de Lima. Proceedings of the Zoological Society of London 51: 70-72. Close : page 72). Type locality "Paucal" [Paucal, Cajamarca, Peru (9 Stephens, L., and M. A. Traylor Jr. (1983) Ornithological gazetteer of Peru. Museum of Comparative Zoology, Cambridge, MA, USA. Close )]. The holotype was believed to be in the Museo de Historia Natural “Javier Prado”, Lima, Peru (10 Zimmer, J. T. (1952). Studies of Peruvian birds. No. 62. The genera Patagona, Sappho, Polyonymus, Ramphomicron, Metallura, Chalcostigma, Taphrolesbia, and Aglaiocercus. American Museum Novitates 1595. Close ), but was not detected there in recent searches (11 Plenge, M. A. (1979) Type specimens of birds in the Museo de Historia Natural "Javier Prado", Lima, Peru. Occasional Papers of the Museum of Zoology, Louisiana State University 53. Close ).

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