A Comparison of Freshwater Mussels (Unionidae) from a Late-Archaic Archeological Excavation with Recently Sampled Verdigris River, Kansas, Populations

Excavations at an archeological site adjacent to the Verdigris River in southeast Kansas unearthed a prehistoric mussel shell midden associated with a probable mussel cooking site. Multiple lines of evidence indicate that the midden was created by Native Americans during the Late Archaic Period and used into the Early Woodland Period (4000 - 1000 B.P.). Over 900 relic mussel valves were identified from the mussel midden. Mussel community characteristics from this archeological site were compared with a recent sampling effort of live mussels from a nearby reach of the Verdigris River. This comparative study demonstrates that the current community composition of mussels differs from that of the prehistoric mussel midden. Four species now considered to be extirpated were found in the mussel midden and several common species differed widely in relative abundance. Measurable midden valves were significantly smaller than recent samples. Seasonal growth-rest lines of well-preserved midden shells suggest that this prehistoric harvest of mussels probably occurred in late summer.