Bivalvia | Unionida | Unionoidea | Unionidae | Ambleminae | Lampsilini | Truncilla
11 specimens + 23 Genbank vouchers

Lea, 1860. Proc. Acad. Nat. Sci. 12: 306.
Lea, 1860. Jour. Acad. Nat. Sci. 4 [O. 8]: 368 [50], pl. 65, fig. 193.
Type(s): HOLOTYPE (MONOTYPY) USNM_85004, Rio Salado, N. Leon, Mexico.
Plagiola (Amygdalonaias) cognata — Simpson (1900), Simpson (1914)
Unio (Lampsilis) cognatus — Martens (1900)
Truncilla cognata — Frierson (1927), Haas (1969), Turgeon et al. (1988), Williams et al. (1993), Howells et al. (1996), ... Czaja et al. (2023), Hopper et al. (2023), Saxon et al. (2023), FMCS (2025), Cummings et al. (2025)
Truncilla donaciformis — R.I. Johnson (1999)
Truncilla cognatus — Haag (2012)
‘Lea’ Sowerby, 1866. Conch. Icon. 16: pl. 39, sp. 214.
(misidentified reference to Unio donaciformis Lea, 1828)
Plagiola (Amygdalonaias) cognata — Simpson (1900)
Plagiola (Amygdalonaias) cognata — Simpson (1900), Simpson (1914)
Unio (Lampsilis) cognatus — Martens (1900)
Truncilla cognata — Frierson (1927), Haas (1969), Turgeon et al. (1988), Williams et al. (1993), Howells et al. (1996), ... Czaja et al. (2023), Hopper et al. (2023), Saxon et al. (2023), FMCS (2025), Cummings et al. (2025)
Truncilla donaciformis — R.I. Johnson (1999)
Truncilla cognatus — Haag (2012)