species Mesonaias explicata (Morelet, 1849): synonymy

Unio explicatus Morelet, 1849

Morelet, 1849. Test. Nov. 1: 28.
Type(s): LECTOTYPE BMNH_93-2-4-2027 (by R.I. Johnson, 1998: 452), flumen Usumasinta, ad pagum Balancan Tabascensium [Mexico].

Lampsilis (Proptera) explicatus — Simpson (1900)
Unio (Uniomerus) explicatus — Martens (1900)
Lampsilis (Proptera) (Group of L. umbrosa) explicata — Simpson (1914)
Lampsilis (Cyrtonaias) explicata — Frierson (1927), Haas (1929)
Lampsilis (sec. Mesonaias) explicatus — Thiele (1934)
Lampsilis (Mesonaias) explicata — Haas (1969), Haas (1969)
Lampsilis explicata — R.I. Johnson (1998), Contreras-Arquieta (2000)
Mesonaias explicatus — Contreras-Arquieta (2000)
Cyrtonaias explicata — Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020), Graf & Cummings (2021), Czaja et al. (2023), Freeman et al. (2025)
Mesonaias explicata — Cummings et al. (2025), Martínez et al. (2026), Barraza et al. (2026)
Sphenonaias explicata — Campbell & Lydeard (2026)

Unio microdon Martens, 1887

Martens, 1887. S.-Ber. Ges. Naturf. Freunde zu Berlin 1887: 107.
Martens, 1900. Biol. Centr.-Amer., Moll.: 504, pl. 35, figs. 1-1c.
Type(s): FIGURED SYNTYPE ZMB_39465, Rio de las Salinas, Guatemala.

Unio (Nephronaias) microdon — Martens (1900)
Nephronaias (Group of N. scamnata) microdon — Simpson (1914)
Elliptio (Sphenonaias) microdon — Frierson (1927)
Lampsilis (Cyrtonaias) microdon — Haas (1929)
Nephronaias (Sphenonaias) microdon — Haas (1969)
Sphenonaias microdon — Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020), Graf & Cummings (2021), Czaja et al. (2023), Freeman et al. (2025)
Mesonaias explicata — Cummings et al. (2025)
Sphenonaias explicata — Campbell & Lydeard (2026)

Lampsilis (Proptera) lividus Simpson, 1900

‘Morelet’ Reeve, 1865. Conch. Icon. 16: pl. 22, sp. 101 [as ‘Unio testudineus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 571.
Simpson, 1914. Descr. Cat. Naiades: 174.
Type(s): HOLOTYPE (MONOTYPY) BMNH_20190695 (by Cummings et al., 2025: 198), Rio Usumacinta, Guatemala.

Lampsilis (Proptera) lividus — Simpson (1900)
Lampsilis (Proptera) (Group of L. umbrosa) livida — Simpson (1914)
Lampsilis (Cyrtonaias) livida — Frierson (1927), Haas (1969)
Lampsilis (Cyrtonaias) microdon — Haas (1929)
Lampsilis explicata — R.I. Johnson (1998)
Cyrtonaias livida — Graf & Cummings (2007), Bogan (2010), Czaja et al. (2023)
Cyrtonaias explicata — Graf & Cummings (2021)
Mesonaias explicata — Cummings et al. (2025)

Unio (Lampsilis) rovirosai Pilsbry, 1900

Pilsbry, 1900. Nautilus 13: 140.
Pilsbry, 1904. Proc. Acad. Nat. Sci. 55: 788, pl. 54, figs. 1-1a.
Type(s): HOLOTYPE (ORIG. DESIG.) ANSP_58916, Laguna de Atasta, nr. S.J. Bautista, Tabasco, Mex.

Lampsilis (Proptera) rovirosai — Simpson (1900)
Unio (Lampsilis) rovirosai — Martens (1900)
Lampsilis rovirosai — Pilsbry (1904)
Lampsilis (Proptera) (Group of L. alata) rovirosai — Simpson (1914)
Proptera rovirosai — Frierson (1927), Haas (1969)
Lampsilis revirosai [sic] — Contreras-Arquieta (2000)
Lampsilis rousrosai [sic] — Contreras-Arquieta (2000)
Potamilus rovirosai — Graf & Cummings (2007), Bogan (2010), Czaja et al. (2023)
Cyrtonaias umbrosa — Graf & Cummings (2021)
Mesonaias explicata — Cummings et al. (2025)

Unio sapperi Ihering, 1901

Simpson, 1900. Proc. U.S. Nat. Mus. 22: 571, footnote 4 [as ‘Unio explicatus’].
Ihering, 1901. Nautilus 15(5): 50.
Type(s): HOLOTYPE (ORIG. DESIG.) SMF_3477, Río Chixoy, Nebemfld. Río Usumacinta, Guatemala.

Lampsilis sapperi — Ihering (1901)
Lampsilis (Proptera) (Group of L. umbrosa) sapperi — Simpson (1914)
Lampsilis (Cyrtonaias) sapperi — Frierson (1927), Haas (1969)
Lampsilis (Cyrtonaias) microdon — Haas (1929)
Cyrtonaias sapperi — Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021)
Mesonaias explicata — Cummings et al. (2025)

Mesonaias explicate Barraza et al., 2026

(error for Unio explicatus Morelet, 1849)
‘Morelet’ Barraza et al., 2026. Check List 22(4): Table 1.

Unio testudineus Reeve, 1865

(misidentified reference to Unio testudineus Morelet, 1849)
‘Morelet’ Reeve, 1865. Conch. Icon. 16: pl. 22, sp. 101.
Type(s): FIGURED SPECIMEN BMNH_20190695, Rio Usumacinta, Guatemala.

Lampsilis (Proptera) lividus — Simpson (1900)
Unio (Uniomerus) explicatus — Martens (1900)
Lampsilis (Proptera) (Group of L. umbrosa) livida — Simpson (1914)
Lampsilis (Cyrtonaias) livida — Frierson (1927)
Lampsilis (Cyrtonaias) microdon — Haas (1929)
Mesonaias explicata — Cummings et al. (2025)

Margaron (Unio) semigranosus Lea, 1870

(misidentified reference to Unio semigranosus von dem Busch in Philippi, 1843)
Lea, 1870. Synopsis Fam. Naiades: 34. [in part]

Lampsilis (Proptera) explicatus — Simpson (1900)
Lampsilis (Proptera) (Group of L. umbrosa) explicata — Simpson (1914)

Unio explicatus Fischer & Crosse, 1894

(reference to Unio explicatus Morelet, 1849)
‘Morelet’ Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 594, pl. 61, fig. 1.

Lampsilis (Proptera) explicatus — Simpson (1900)
Unio (Uniomerus) explicatus — Martens (1900)
Lampsilis (Proptera) (Group of L. umbrosa) livida — Simpson (1914)
Lampsilis (Cyrtonaias) livida — Frierson (1927)
Lampsilis explicata — R.I. Johnson (1998)

Lampsilis (Proptera) explicatus Simpson, 1900

(reference to Unio explicatus Morelet, 1849)
‘Morelet’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 571. [in part]

Lampsilis (Proptera) (Group of L. umbrosa) explicata — Simpson (1914)

Lampsilis (Proptera) explicatus Simpson, 1900

(reference to Unio explicatus Morelet, 1849)
‘Morelet’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 571, footnote 4. [in part]

Lampsilis sapperi — Ihering (1901)
Lampsilis (Proptera) (Group of L. umbrosa) sapperi — Simpson (1914)

Lampsilis revirosai Contreras-Arquieta, 2000

(error for Unio (Lampsilis) rovirosai Pilsbry, 1900)
Contreras-Arquieta, 2000. Mexicoa 2(1): 44.

Lampsilis rousrosai Contreras-Arquieta, 2000

(error for Unio (Lampsilis) rovirosai Pilsbry, 1900)
‘Pilsbry’ Contreras-Arquieta, 2000. Mexicoa 2(1): 44.