A late Miocene (Hemphillian) freshwaterfish (Osteichthyes) fauna from MobileCounty, Alabama, USA
Systematic descriptions of North American Miocene freshwater fishes are extremely uncommon, with those from the Gulf Coastal Plain region being completely absent. In this study we examined 324 historically collected freshwater fish elements derived from the late Miocene (Hemphillian) Mauvilla fossil site located in Mobile County, Alabama, USA. Analysis of these elements confirmed the presence of three unequivocal taxa including Atractosteus sp. cf. A. spatula, Ictalurus spp., and Aplodinotus grunninens. The preserved elements consisted of spines, pharyngeal bones, pharyngeal teeth, and scales, likely indicating a taphonomic bias towards large individuals with robust elements. The co-occurrence of these three taxa indicate they were derived from a medium-to-large river fish assemblage, suggesting that one or more of the rivers that constitute the nearby Mobile Basin may have been present in the region during the late Miocene. Molecular divergence estimates and morphological similarity to modern representatives both support the presence of these extant taxa in the late Miocene, and the examined remains represent some of the earliest fossil occurrences of these extant taxa. These three taxa also represent the first biogeographic occurrence of each in the late Miocene of both Alabama and the Gulf Coastal Plain of North America and helps to improve our understanding of Miocene freshwater fish assemblages. [ABSTRACT FROM AUTHOR]
Ebersole, J. A.,
& Jacquemin, S. J.
(2020). A late Miocene (Hemphillian) freshwaterfish (Osteichthyes) fauna from MobileCounty, Alabama, USA. Historical Biology, 32 (6), 750-763.