ɪt wʌz haɪpˈɑːθəsˌaɪzd ðæt ˈɛl. nˈɛmɐtˌɑːptɚɹˌɪks ænd ˈɛl. pˈɪsɪŋɡjˌuːɐbˌiː kəmpɹˈaɪz ɐ mˌɑːnoʊfaɪlˈɛɾɪk ɐsˈɛmblɪdʒ, ɡˈɪvən ðə fˈækt ðætðə pˈɛktɚɹəl fˈɪn ʌv ðiːz spˈiːsiːz kənsˈɪsts əvə sˈɪŋɡəl ɹˈeɪ ænd ðə ɹˈeɪ ɪz ɪnðə fˈɔːɹm əvə lˈɔŋ fˈɪləmənt, ɐ kəndˈɪʃən nˌɑːt pɹˈɛzənt ɪn ˌɛni ˈʌðɚ tɹˈɪtʃəmˌɪktɚɹˌɪdz ðˈʌs fˈɑːɹ dᵻskɹˈaɪbd.
It was hypothesized that L. nematopteryx and L. picinguabae comprise a monophyletic assemblage, given the fact that the pectoral fin of these species consists of a single ray and the ray is in the form of a long filament, a condition not present in any other trichomycterids thus far described.