Bivalvia | Unionida | Unionoidea | Unionidae | Ambleminae | Lampsilini | Mesonaias
5 available nominal species synonyms (13 total synonyms)
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), Nagel (2025)
Cyrtonaias livida — Graf & Cummings (2007), Bogan (2010), Czaja et al. (2023)
Cyrtonaias sapperi — Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021), Nagel (2025)
Potamilus rovirosai — Graf & Cummings (2007), Bogan (2010), Czaja et al. (2023)
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)
Cyrtonaias umbrosa — Graf & Cummings (2021)
Mesonaias explicata — Cummings et al. (2025), Martínez et al. (2026), Barraza et al. (2026)
Sphenonaias explicata — Campbell & Lydeard (2026)
Usumacinta River, Mexico and Guatemala. (Central America: CA1)


BMNH_20190695
Rio Usumacinta, Guatemala
holotype
Lampsilis lividus Simpson, 1900

SMF_3477
Río Chixoy, Nebemfld. Río Usumacinta, Guatemala
holotype
Lampsilis sapperi Ihering, 1901

BMNH_93-2-4-2027
flumen Usumasinta, ad pagum Balancan Tabascensium [Mexico].
lectotype
Unio explicatus Morelet, 1849

MNHN_IM-2000-1693
Rio Usumacinta, Guatemala
paralectotypes
Unio explicatus Morelet, 1849

ZMB_39465
Rio de las Salinas, Guatemala
figured syntype
Unio microdon Martens, 1887

ANSP_58916
Laguna de Atasta, nr. S.J. Bautista, Tabasco, Mex.
holotype
Unio rovirosai Pilsbry, 1900

SMF_3478
Rio Chixoy, Nebenfl. d. Rio Usumacinta, Guatemala
paratypes
Lampsilis sapperi Ihering, 1901

AMNH_140572
Rio de la Pasion, Treasure Island, Peten, Guatemala

AMS_102110
Rio Usumacinta, 5.5 mi SE Emillano Zapata, Tabasco, Mexico

AMS_102123
small river, 3 mi SE Emiliano Zapata, Tabasco, Mexico

INHS_24861
Rio Usumacinta, Boca Lacantum, Chiapas, Mexico

MCZ_288415
3 mi SE Emiliano Zapata, Tabasco, Mexico

MCZ_288418
small river, 3 mi SE Emiliano Zapata, Tabasco, Mexico

MNHN_MP_1297
Rio Usumacinta, Guatemala

OSUM_18872
Rio de la Pasion, Peten, Guatemala

UF_507903
Rio De La Pasion, 5.5 miles east of Sayaxche, El Peten Department, Guatemala 16.536339, -90.103900

UF_164047
Rio San Pedro, 3 km N La Palma, Tabasco, Mexico.

UF_164060
Rio San Pedro, 3 km N La Palma, Tabasco, Mexico.

UF_164530
Rio San Pedro, 4 km N La Palma, Tabasco, Mexico

UF_190666
Rio Usumacinta, Emiliano Zapata, Tabasco, Mexico

UF_190667
Rio Usumacinta, Emiliano Zapata, Tabasco, Mexico

UF_507898
Usumacinta River, opposite of Emiliano Zapata. Tabasco, Mexico. 17.749685, -91.766995

USNM_128995
Rio Chixoy, Rompido, Peten, Guatemala

USNM_783045
Rio de la Pasion, Guatemala

USNM_160741
Rio Usumacinta, Monte Cristo, Tabasco, Mexico
ZMA_418019. Mexico
UF_507898 (2015-0719). (16S: MK001801, 28S: MK001835, COI: MK001769, go to GenBank) Mexico, Tabasco, Usumacinta River, opposite Emiliano Zapata (17.749685, -91.766995) .
UF_507898 (2015-0720). (16S: MK001802, 28S: MK001836, COI: MK001770, go to GenBank) ditto.
Z_12423 (2015-543). (16S: MK001804, 28S: MK001838, COI: MK001772, go to GenBank)
Z_12424 (2015-502). (16S: MK001803, 28S: MK001837, COI: MK001771, go to GenBank)