MUSSELpdb
Taxonomy
Species & Genus Richness of
freshwater mussels
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Species & Genus Richness of
freshwater bivalves
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freshwater mussels
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Data last updated
Thu 19 March 2026
Bivalvia | Unionida | Unionoidea | Unionidae | Ambleminae | Lampsilini
genus Pachynaias Crosse & Fischer, 1894: cladomics
1 Recent valid species (1 total species)
Cladomics pages are experimental — even more so than the rest of this site!
The purpose of the cladomics pages for each genus and family-group level taxon is to provide statistics and references indicating the extent to which published phylogenetic work supports the classification used here.
The Cladomics Summary provides an overview of the number of studies that have included terminal species representing this taxon as well as an indication of how frequently it has been recovered as monophyletic.
Following the summary, the available published clades representing the taxon are listed.
For more information, visit the Cladomics FARQ (frequently asked rhetorical questions) page. Abbreviations for the various statistics are explained on the FARQ!
Cladomics Summary
number of species = 1 (1 total)
analyzed in 9 cladograms in 6 publications
maximum number of terminals in an analysis = 1 (mean = 1, median = 1)
Cladograms
Campbell & Lydeard, 2026 [Publ 4810], fig. 6-14
** Top Monophyly Cladogram ** ** Top Sister-Group Cladogram **
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 630 | 92 | 26 | -- |
+-------- Potamilus_inflatus
+--------+
| | +----- Potamilus_ohiensis
| +--+
| | +-- Potamilus_amphichaenus
| +--+
+-----------------------------------+ +-- Potamilus_streckersoni
| |
| | +----- Potamilus_fragilis__2
| | +--------+
| | | | +-- Potamilus_leptodon
| | | +--+
| +--+ +-- Potamilus_fragilis__1
| |
| | +----------- Potamilus_metnecktayi
| | |
| +--+ +-------- Potamilus_alatus__3
| | |
| +--+ +----- Potamilus_alatus__2
--+ | |
| +--+----- Potamilus_purpuratus__2
| |
| | +-- Potamilus_alatus__1
| +--+
| +-- Potamilus_purpuratus__1
|
| +-- Villosa_villosa
| +-----------------------------------------------+
| | +-- Atlanticoncha
| |
| | +-- Cambarunio_nebulosus
| | +--------------------------------------------+
+--+ | +-- Ligumia
| |
| | +-------- Leaunio_umbrans
| | +-----------------------------------+
| | | | +----- Cambarunio_taeniatus
+--+ | +--+
| | | +-- Cambarunio_iris
| | +--+
| | +-- Cambarunio_simus
| |
| | +----------------------------------------- Hamiota
| | |
+--+ | +----------------------- Pachynaias_spheniopsis **
| | |
| | +--------------+ +-------------------- Sagittunio
| | | | |
| | | | | +----- Ellipsaria
| | | +--+ +-----------+
| | | | | | +-- Potamilus_capax
| | | | | +--+
| | | | | +-- Truncilla
+--+ | +--+
| | | +----- Medionidus_acutissimus
| | | +--------+
| | | | | +-- Lemiox
| | | | +--+
| | +--+ +-- Medionidus_penicillatus
| | |
| | | +----------- Ptychobranchus
| | | |
| | +--+ +-- Cyprogenia_aberti__2
| | | +-----+
+--+ | | +-- Dromus
| +--+
| | +----- Cyprogenia_stegaria__2
| +--+
| | +-- Cyprogenia_aberti__1
| +--+
| +-- Cyprogenia_stegaria__1
|
| +-- Villosa_delumbis
| +--------------------------------+
| | +-- Villosa_vibex
| |
| | +-------------- Obovaria_olivaria
| | |
| | +-----------------+ +-- Venustaconcha
| | | | +--------+
| | | | | +-- Epioblasma
| | | +--+
| | | | +-------- Obovaria_retusa
+--+ | +--+
| | | +----- Obovaria_choctawensis
| | +--+
| | | +-- Obovaria_unicolor
| | +--+
| | +-- Obovaria_subrotunda
| |
| | +-- Mesonaias
| | +-----------------------+
| | | +-- Obovaria_arkansasensis
| | |
+--+ +--+ +-- Lampsilis_splendida
| | | +--------------------+
| | | | +-- Lampsilis_bracteata
| | | |
| | +--+ +-- Lampsilis_fasciola
| | | +-----------------+
| | | | +-- Ortmanniana_pectorosa
| | +--+
| | | +----------------- Lampsilis_ornata
| | | |
| | +--+ +-------------- Lampsilis_ovata__2
| | | |
| | +--+ +----------- Lampsilis_dolabraeformis
| | | |
| | | | +----- Lampsilis_cardium__2
| | +--+ +--+
| | | | | +-- Lampsilis_cardium__1
+--+ | | +--+
| +--+ +-- Lampsilis_satura
| |
| | +----- Lampsilis_cariosa__2
| +--+
| | +-- Lampsilis_ovata__1
| +--+
| +-- Lampsilis_cariosa__1
|
| +----------- Ortmanniana_ligamentina__2
| +--------------+
| | | +-------- Lampsilis_abrupta
| | +--+
| | | +----- Lampsilis_higginsii__2
| | +--+
| | | +-- Ortmanniana_ligamentina__1
| | +--+
+--+ +-- Lampsilis_higginsii__1
|
| +----- Medionidus_conradicus
| +-----------------+
| | | +-- Leaunio_lienosus
| | +--+
| | +-- Leaunio_vanuxemensis
| |
+--+ +-- Lampsilis_floridensis
| +-----------------+
| | +-- Lampsilis_teres
| |
| | +-- Lampsilis_siliquoidea__1
+--+ |
| +-- Lampsilis_siliquoidea__2
| +--------------+
| | +-- Lampsilis_powellii__1
| | |
+--+ +-- Lampsilis_powellii__2
|
| +-------------- Lampsilis_sietmani
| |
+--+ +-- Lampsilis_straminea__2
| +--------+
| | +-- Lampsilis_virescens
+--+
| +-------- Lampsilis_hydiana__2
+--+
| +----- Lampsilis_hydiana__1
+--+
| +-- Lampsilis_bergmanni
+--+
+-- Lampsilis_straminea__1
Pfeiffer et al., 2019 [Publ 3937], fig. 4-5
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 56 | 4 | 4 | -- |
+----------- Obliquaria --+ | +-------- Cyrtonaias +--+ | +----- Leaunio +--+ | +-- Lampsilis +--+ +-- Pachynaias_spheniopsis **
Smith et al., 2020 [Publ 4129], fig. 2-3
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 27 | 19 | 7 | -- |
+-------------- Obliquaria | --+ +----------- Cyrtonaias | | | | +-- Pachynaias_spheniopsis ** +--+ +-----+ | | +-- Lampsilis | | +--+ +-- Ellipsaria | +--+ | | +-- Truncilla +--+ | +-- Atlanticoncha +--+ +-- Potamilus
Pfeiffer et al., 2019 [Publ 3937], fig. 6
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 56 | 4 | 4 | -- |
+----------- Obliquaria --+ | +-------- Cyrtonaias +--+ | +----- Leaunio +--+ | +-- Lampsilis +--+ +-- Pachynaias_spheniopsis **
Inoue et al., 2020 [Publ 4128], fig. 3
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 21 | 10 | 10 | -- |
+----------------------- Cyrtonaias | --+ +-------------------- Ptychobranchus | | +--+ +----------------- Ligumia | | +--+ +-------------- Potamilus | | +--+ +----------- Pachynaias_spheniopsis ** | | | | +-- Epioblasma +--+ +-----+ | | +-- Truncilla | | +--+ +-- Mesonaias | +--+ | | +-- Cambarunio +--+ | +-- Ortmanniana +--+ +-- Lampsilis
Inoue et al., 2020 [Publ 4128], fig. 2
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 22 | 11 | 11 | -- |
+-- Glebula
+--------+
| +-- Cyrtonaias
|
--+ +-------- Potamilus
| |
| | +-- Ptychobranchus
+--+ +--+
| | +-- Truncilla
| |
| | +-- Ortmanniana
+--+ |
| +-- Epioblasma
| |
| +-- Lampsilis
| |
+--+-- Ligumia
|
+-- Cambarunio
|
+-- Pachynaias_spheniopsis **
|
+-- Mesonaias
Smith et al., 2020 [Publ 4129], fig. 1
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 27 | 19 | 7 | -- |
+-------------- Obliquaria | --+ +----------- Cyrtonaias | | | | +-- Pachynaias_spheniopsis ** +--+ +-----+ | | +-- Lampsilis | | +--+ +-- Ellipsaria | +--+ | | +-- Truncilla +--+ | +-- Atlanticoncha +--+ +-- Potamilus
Pfeiffer et al., 2019 [Publ 3866], fig. 1
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 30 | 11 | 11 | -- |
+-- Cyrtonaias
+--------------------+
| +-- Glebula
--+
| +-------------------- Potamilus
| |
+--+ +-- Truncilla
| +--------------+
| | +-- Ptychobranchus
+--+
| +-------------- Pachynaias_spheniopsis **
| |
+--+ +----------- Mesonaias
| |
+--+ +-- Lampsilis
| +-----+
| | +-- Ortmanniana
+--+
| +----- Cambarunio
+--+
| +-- Epioblasma
+--+
+-- Ligumia
Freeman et al., 2025 [Publ 4443], fig. 2
| tT | bi | riS | oT | roT | roS | iD | |
| 1 | 1 | 0 | 1 | 5 | 1 | 1 | -- |
+-- Mesonaias --+ +-- Pachynaias_spheniopsis **
