species Psoronaias crocodilorum (Morelet, 1849): synonymy

Unio crocodilorum Morelet, 1849

Morelet, 1849. Test. Nov. 1: 28.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_1893-2-4-2030 (by R.I. Johnson, 1971: 81), River Usumacinta, Central America.

Unio (sec. Elliptio) crocodilarum [sic] — Simpson (1900), Simpson (1914)
Unio (Psoronaias) crocodilorum — Martens (1900)
Psoronaias crocodilorum — Frierson (1917), Frierson (1927), Haas (1930), Haas (1969), Graf & Cummings (2007), Bogan (2010), Cummings et al. (2025)
Psoronaias crocodilarum [sic] — Haas (1929)
Psoronaias semigranosus — Goodrich & van der Schalie (1937)
Psoronaias semigranosa — Graf & Cummings (2021)

Unio ostreatus Morelet, 1849

Morelet, 1849. Test. Nov. 1: 29.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_94-3-22-2 (by R.I. Johnson, 1971: 90), flumen Usumacinta, Guatemala.

Quadrula (Rotundaria) ostreata — Simpson (1900), Simpson (1914)
Unio (Psoronaias) ostreatus — Martens (1900)
Psoronaias ostreatus — Frierson (1927), Haas (1930)
Psoronaias ostreata — Haas (1929), Haas (1969), Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021), Czaja et al. (2023)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio testudineus Morelet, 1849

Morelet, 1849. Test. Nov. 1: 28.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_94-3-22-1 (by R.I. Johnson, 1971: 96), flumen Usumacinta, Guatemala.

Unio (sec. Elliptio) testudineus — Simpson (1900), Simpson (1914)
Unio (Psoronaias) semigranosus var. testudineus — Martens (1900)
Psoronaias semigranosus — Frierson (1927)
Psoronaias testudinea — Haas (1929), Haas (1969)
Psoronaias testudineus — Haas (1930)
Psoronaias testudinarea [sic] — Bogan (2010)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio morini Morelet, 1851

Morelet, 1851. Test. Nov. 2: 25.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_93-2-4-2026 (by R.I. Johnson, 1971: 88), Rio Usumacinta, Guatemala.

Unio (sec. Elliptio) morini — Simpson (1900), Simpson (1914)
Unio (Psoronaias) morini — Martens (1900)
Psoronaias morini — Frierson (1927), Haas (1929), Haas (1930), Haas (1969), Graf & Cummings (2007), Bogan (2010)
Psoronaias semigranosus — Goodrich & van der Schalie (1937)
Psoronaias semigranosa — Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio psoricus Morelet, 1851

Morelet, 1851. Test. Nov. 2: 25.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_93-2-4-2033 (by R.I. Johnson, 1971: 81), Rio Usumacinta, Tabasco.

Unio (sec. Elliptio) psoricus — Simpson (1900), Simpson (1914)
Unio (Psoronaias) psoricus — Martens (1900)
Psoronaias psoricus — Frierson (1917), Haas (1930), Thiele (1934)
Psoronaias semigranosus-psoricus — Frierson (1927)
Psoronaias psorica — Haas (1929), Haas (1969), Haas (1969), Bogan (2010)
Psoronaias semigranosus — Goodrich & van der Schalie (1937)
Psoronaias semigranosa — Graf & Cummings (2007), Pfeiffer et al. (2019), Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio corium Reeve, 1864

Reeve, 1864. Conch. Icon. 16: pl. 10, sp. 39.
Type(s): HOLOTYPE (MONOTYPY) BMNH_1965209, Chiapas, Mexico.

Unio (sec. Elliptio) corium — Simpson (1900), Simpson (1914)
Unio (Psoronaias) corium — Martens (1900)
Unio corium — Pilsbry (1910)
Psoronaias semigranosus-corium — Frierson (1927)
Psoronaias semigranosus — Haas (1930), Goodrich & van der Schalie (1937)
Psoronaias semigranosa corium — Haas (1969)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio percompressus Martens, 1887

Martens, 1887. S.-Ber. Ges. Naturf. Freunde zu Berlin 1887: 107.
Martens, 1900. Biol. Centr.-Amer., Moll.: 496, pl. 32, figs. 1-3.
Type(s): LECTOTYPE ZMB_39463 (by Cummings et al., 2025: 315), Rio de las Salinas, Guatemala.

Quadrula (Rotundaria) percompressa — Simpson (1900), Simpson (1914)
Unio (Psoronaias) percompressus — Martens (1900)
Psoronaias percompressus — Frierson (1927)
Rotundaria percompressa — Haas (1929)
Amblema (Psorula) percompressa — Haas (1930)
Psorula percompressa — Haas (1969), Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020)
Psoronaias percompressa — Graf & Cummings (2021), Czaja et al. (2023), Campbell & Lydeard (2026)
Psorula percompressus — Freeman et al. (2025)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio usumasintae Crosse & Fischer, 1893

Crosse & Fischer, 1893. J. de Conch. 40: 294 [as ‘usumasintæ’].
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(15): 574, pl. 63, fig. 4; pl. 67, fig. 5 [as ‘usumasintæ’].
(renamed Unio usumacintae Martens, 1900)
Type(s): TYPE LOST XXX_UNKNOWN, in flumine Usumasinta, Provinciæ Peten dictæ, Guatemalæ.

Quadrula (Rotundaria) usumasintæ — Simpson (1900), Simpson (1914)
Unio (Pleurobema) usumacintæ — Martens (1900)
Amblema (Psorula) usumasintae — Haas (1930)
Psorula usumasintae — Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020), Freeman et al. (2025)
Psoronaias usumasintae — Graf & Cummings (2021), Czaja et al. (2023), Campbell & Lydeard (2026)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio pigerrimus Crosse & Fischer, 1894

Crosse & Fischer, 1894. J. de Conch. 41: 293.
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 582, pl. 65, figs. 1-1a.
Type(s): LECTOTYPE MNHN_IM-2000-1761 (by Cummings et al., 2025: 316), Mexique.

Unio (sec. Elliptio) pigerrimus — Simpson (1900), Simpson (1914)
Unio (Psoronaias) psoricus var. pigerrimus — Martens (1900)
Elliptio (Barynaias) pigerrimus — Frierson (1927), Haas (1929)
Elliptio (sec. Barynaias) pigerrima — Thiele (1934)
Barynaias pigerrimus — Haas (1969), Czaja et al. (2023)
Barynaias pigerrima — Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio crocodilorum var. B semipustulata Fischer & Crosse, 1894

Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 578, pl. 60, fig. 4.
(intro'd as intra-sp. of Unio crocodilorum Morelet, 1849)
Type(s): HOLOTYPE BMNH_1893-2-4-2032, River Usumacinta, Guatemala.

Unio (Psoronaias) crocodilorum — Martens (1900)
Psoronaias crocodilorum — Frierson (1927), Haas (1969), Cummings et al. (2025)
Psoronaias crocodilarum [sic] — Haas (1929)

Unio crocodilorum var. G praestricta Fischer & Crosse, 1894

Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 578, pl. 60, fig. 5.
(intro'd as intra-sp. of Unio crocodilorum Morelet, 1849)
Type(s): HOLOTYPE BMNH_1893-2-4-2031, River Usumacinta, Guatemala.

Unio (Psoronaias) crocodilorum — Martens (1900)
Psoronaias crocodilorum — Frierson (1927), Haas (1969), Cummings et al. (2025)

Quadrula rudis Simpson, 1900

Simpson, 1900. Proc. Acad. Nat. Sci. 52: 82, pl. 3, fig. 2.
Simpson, 1914. Descr. Cat. Naiades: 910.
Type(s): HOLOTYPE (MONOTYPY) USNM_84210, Rio Taxtunilha, (tributary to the Rio de la Pasion), Guatemala.

Quadrula rudis — Simpson (1900)
Unio (Psoronaias) crocodilorum var. rudis — Martens (1900)
Quadrula (Rotundaria) rudis — Simpson (1914)
Psoronaias rudis — Frierson (1927)
Rotundaria rudis — Haas (1929)
Amblema (Psorula) rudis — Haas (1930)
Amblema (sec. Psorula) rudis — Thiele (1934)
Psoronaias semigranosus — Goodrich & van der Schalie (1937)
Psorula rudis — Haas (1969), Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020), Freeman et al. (2025)
Psoronaias semigranosa — Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Unio crocodilarum ‘Morelet’ of Authors

‘Morelet’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 702.
Simpson, 1914. Descr. Cat. Naiades: 591.
Haas, 1929. Senckenbergiana 11: 332.
(error for Unio crocodilorum Morelet, 1849)

Psoronaias crocodilorum — Cummings et al. (2025)

Unio usumacintae Martens, 1900

Crosse & Fischer, 1893. J. de Conch. 40: 294 [as ‘usumasintæ’].
Martens, 1900. Biol. Centr.-Amer., Moll.: 500 [as ‘usumacintæ’].
(new name for Unio usumasintae Crosse & Fischer, 1893)

Unio (Pleurobema) usumacintæ — Martens (1900)
Psoronaias usumacintae — Frierson (1927)
Rotundaria usumacintae — Haas (1929)
Psorula usumacintae — Haas (1969)
Psoronaias crocodilorum — Cummings et al. (2025)

Quadrula (Rotundaria) profunda Simpson, 1914

Simpson, 1914. Descr. Cat. Naiades: 907.
Type(s): HOLOTYPE (MONOTYPY) USNM_128987, Usumacinta River, Guatemala.

Quadrula (Rotundaria) profunda — Simpson (1914)
Psoronaias profunda — Frierson (1927), Graf & Cummings (2021), Czaja et al. (2023), Campbell & Lydeard (2026)
Rotundaria profunda — Haas (1929)
Amblema (Psorula) profunda — Haas (1930)
Psorula profunda — Haas (1969), Graf & Cummings (2007), Bogan (2010), Pfeiffer et al. (2019), Inoue et al. (2020), Freeman et al. (2025)
Psoronaias crocodilorum — Cummings et al. (2025)

Quadrula (Rotundaria) quadrata Simpson, 1914

Simpson, 1914. Descr. Cat. Naiades: 911.
Type(s): LECTOTYPE USNM_128996 (by R.I. Johnson, 1975: 18), Usumacinta River, Guatemala.

Quadrula (Rotundaria) quadrata — Simpson (1914)
Psoronaias quadrata — Frierson (1927), Graf & Cummings (2021)
Rotundaria quadrata — Haas (1929)
Amblema (Psorula) quadrata — Haas (1930)
Psorula quadrata — Haas (1969), Graf & Cummings (2007), Bogan (2010)
Psoronaias crocodilorum — Cummings et al. (2025)

Psoronaias martensi Frierson, 1927

Martens, 1900. Biol. Centr.-Amer., Moll.: 494, pl. 31, figs. 1-2 [as ‘Unio psoricus’].
Frierson, 1927. Check List N. Amer. Naiades: 64, sp. 279.
Type(s): LECTOTYPE [AS TYPE] ZMB/MOLL_39466 (by R.I. Johnson, 1972: 146), N. Guatemala: Rio de las Salinas.

Psoronaias martensi — Frierson (1927), Haas (1930), Haas (1969), Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Rotundaria salinarum Haas, 1929

Haas, 1929. Senckenbergiana 11: 339, figs. 20-21.
Type(s): HOLOTYPE (ORIG. DESIG.) SMF_3487, Rio de las Salinas, N. Guatemala.

Rotundaria salinarum — Haas (1929)
Amblema (Psorula) salinarum — Haas (1930), Haas (1969)
Psorula salinarum — Haas (1969), Graf & Cummings (2007), Bogan (2010)
Psoronaias salinarum — Graf & Cummings (2021)
Psoronaias crocodilorum — Cummings et al. (2025)

Psoronaias semigranosa ‘von dem Busch in Philippi’ of Authors

‘von dem Busch in Philippi’ of Authors.
Pfeiffer et al., 2019. Zool. Scripta 48: 108.
Pfeiffer et al., 2019. MPE 137: 116.
Inoue et al., 2020. Zootaxa 4816(4): 460.
Smith et al., 2020. Cladistics 36: 507.
Freeman et al., 2025. Malacologia 67(1/2): 256, Table 1.
(misidentified reference to Unio semigranosus von dem Busch in Philippi, 1843)

Psoronaias crocodilorum — Cummings et al. (2025)

Unio crocolilorum Lea, 1852

‘Morelet’ Lea, 1852. Synopsis Fam. Naiades: 39.
(error for Unio crocodilorum Morelet, 1849)

Unio testidineus Lea, 1852

‘Morelet’ Lea, 1852. Synopsis Fam. Naiades: 40.
(error for Unio testudineus Morelet, 1849)

Unio pliciferus Reeve, 1864

‘Lea’ Reeve, 1864. Conch. Icon. 16: pl. 10, sp. 37; errata [changed to ‘U. crocodilorum Morelet’].
(misidentified reference to Unio pliciferus Lea, 1838; error for Unio crocodilorum Morelet, 1849)

Unio (Psoronaias) crocodilorum — Martens (1900)
Unio (sec. Elliptio) crocodilarum [sic] — Simpson (1900), Simpson (1914)
Psoronaias crocodilorum — Frierson (1927)

Unio semigranosus Reeve, 1864

‘Philippi’ Reeve, 1864. Conch. Icon. 16: pl. 10, sp. 36; errata.
(misidentified reference to Unio semigranosus von dem Busch in Philippi, 1843)
Type(s): FIGURED SPECIMEN BMNH_196496, Mexico.

Unio (sec. Elliptio) testudineus — Simpson (1900), Simpson (1914)
Unio (Psoronaias) semigranosus var. testudineus — Martens (1900)

Unio psoricus Martens, 1900

Martens, 1900. Biol. Centr.-Amer., Moll.: 494, pl. 31, figs. 1-2.
(reference to Unio psoricus Morelet, 1851)

Psoronaias martensi — Frierson (1927), Haas (1969)

Psoronaias testudinarea Bogan, 2010

‘Morelet’ Bogan, 2010. FADA: [web].
(error for Unio testudineus Morelet, 1849)