Osteichthyans from the Tallahatta–Lisbon Formation Contact (middle Eocene–Lutetian) Pigeon Creek, Conecuh-Covington Counties, Alabama with Comments on Transatlantic Occurrences in the Northern Atlantic Ocean Basin

Abstract

A disconformity and lag deposit that separates the Tallahatta and Lisbon Formations along Pigeon Creek near Red Level, Conecuh-Covington Counties, Alabama contains osteichthyan remains belonging to: Pycnodus sp.; Lepisosteus sp.; Albula sp.; Egertonia isodonta Cocchi, 1864; Cylindracanthus rectus Agassiz, 1843; Sphyraena sp.; Triciurides cf. T. sagittidens Winkler, 1874; Scomberomorus sp.; Ariidae gen. indet.; Ostraciidae gen. indet., and cf. Beryciformes. This fossil osteichthyan assemblage is similar to other contemporaneous nearshore faunas found throughout Alabama, the Atlantic and Gulf Coastal Plains, and elsewhere throughout the Northern Ocean Basin. The accumulation and concentration of osteichthyans between the Tallahatta and Lisbon Formations is the result of third order eustatic sea level fluctuation and reflects a complex taphonomic history of exhumation, transport, and reburial across a shallow, middle Eocene shelf. Wide spread distribution of osteichthyan genera found in the Pigeon Creek assemblage demonstrates the continuity of shallow marine shelf environments of the Northern Atlantic Ocean Basin during the middle Eocene and the utility of osteichthyans in regional and transatlantic stratigraphic studies