Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Bivalvia Unionoida Unionidae

Scientific Name: Alasmidonta mccordi
Species Authority: Athearn, 1964
Common Name(s):
English Coosa Elktoe
Taxonomic Notes: The current spelling of the specific name is correct. Clarke's (1985) spelling change, Alasmidonta maccordi, was unjustified and constituted a recommendation only (Turgeon et al. 1998).

A list of synonyms for this species can be found on The MUSSEL project web site (Graf and Cummings 2011).

Assessment Information [top]

Red List Category & Criteria: Extinct ver 3.1
Year Published: 2011
Date Assessed: 2011-07-22
Assessor(s): Cummings, K. & Cordeiro, J.
Reviewer(s): Seddon, M.B., Böhm, M. & Collen, B.
Contributor(s): Bogan, A.E., Dyer, E., Whitton, F., Soulsby, A.-M., McGuinness, S., De Silva, R., Milligan, H.T., Kasthala, G., Herdson, R., Thorley, J., McMillan, K. & Collins, A.
Alasmidonta mccordi was listed in 1996 (Baillie and Groombridge 1996) as Critically Endangered due to insufficient survey information. In 2000, surveys confirmed that A. mccordi is Extinct (Bogan 2000) and there has been no further evidence in recent years to suggest otherwise (Bogan et al. 2008).
Previously published Red List assessments:
2000 Extinct (EX)
1996 Critically Endangered (CR)

Geographic Range [top]

Range Description:This species was known only from a single specimen collected from the Coosa River in St. Clair County, Alabama, prior to its impoundment (Athearn 1964, Mirarchi et al. 2004). It is currently believed to be extinct (Bogan et al. 2008).
Countries occurrence:
Regionally extinct:
United States (Alabama)
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There are no individuals known to be extant (NatureServe 2009).
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:The only known specimen of this species was collected alive from shallow, swift water in sand and gravel substrate in an area thickly strewn with rock debris (Athearn 1964).

Threats [top]

Major Threat(s): This species is now considered to be Extinct. Impoundment of the Coosa River is thought to have caused the extinction of this species.

Conservation Actions [top]

Conservation Actions: This species has been given a NatureServe Global Heritage Status Rank of GX - presumed extinct (NatureServe 2009), and was assigned an American Fisheries Society Status of Possibly Extinct (1 Jan 1993), and a previous IUCN Red List Category of EX (2000 ver 2.3).

Classifications [top]

5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable  major importance:Yes

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
7. Natural system modifications -> 7.2. Dams & water management/use -> 7.2.11. Dams (size unknown)
♦ timing: Past, Unlikely to Return ♦ scope: Whole (>90%) ♦ severity: Unknown ⇒ Impact score: Past Impact 
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 2. Species Stresses -> 2.1. Species mortality

Bibliography [top]

Athearn, H.D. 1964. Three new unionids from Alabama and Florida and a note on Lampsilis jonesi. The Nautilus 77(4): 134-139.

Bogan, A.E., Huang, Y., Raley, M. and Levine, J.F. 2008. Intraspecific phylogenetic relationships in the freshwater bivalve genus Alasmidonta (Bivalvia: Unionidae). North Carolina Department of Transportation, North Carolina.

Clarke, A.H. 1985. The tribe Alasmidontini (Unionidae: Anodontinae), Part II: Lasmigona and Simpsonaias. pp. iii + 75. Smithsonian Contributions to Zoology.

Graf, D.L. and Cummings, K.S. 2011. The MUSSEL Project Database: MUSSELp. Available at: (Accessed: 18/08/2011).

IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.2). Available at: (Accessed: 10 November 2011).

Mirarchi, R.E., Garner, J.T., Mettee, M.F. and O'Neil, P.E. 2004. Imperilled Aquatic Molluscs and Fishes. University of Alabama Press, Tuscaloosa, Alabama.

NatureServe. 2009. NatureServe Explore: An online encyclopaedia of life [web application]. Version 7.1. Arlington, Virginia Available at:

Turgeon, D.D., Quinn, Jr. J.F., Bogan, A.E., Coan, E.V., Hochberg, F.G., Lyons, W.G., Mikkelsen P.M., Neves, R.J., Roper, C.F.E., Rosenberg, G., Roth, B., Scheltema, A., Thompson, F.G., Vecchione, M. and Williams, J.D. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada. American Fisheries Society, Mollusks.

Citation: Cummings, K. & Cordeiro, J. 2011. Alasmidonta mccordi. In: The IUCN Red List of Threatened Species 2011: e.T780A13078346. . Downloaded on 09 October 2015.
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