Xiphiorhynchus cf. X. Eocaenicus (Woodward, 1901), (Scombroidei: Xiphiidae: Xiphiorhynchinae) from the middle Eocene of Mississippi, the first Transatlantic distribution of a species of Xiphiorhynchus

• Main Authors: Fierstine, Harry L., Starnes, James E.
• Format: Text
• Language: unknown
• Published: DigitalCommons@CalPoly 2005
• Subjects: Biology; Woodward; North Atlantic
• Online Access: https://digitalcommons.calpoly.edu/bio_fac/65; https://digitalcommons.calpoly.edu/context/bio_fac/article/1066/viewcontent/Xiphiorhynchus_cf_X_Eocaenicus_Woodward_Scombroidei.pdf

An anterior (distal) rostrum (MMNS 2957) from the Moodys Branch Formation (late middle Eocene). Tesheva Creek, Yazoo County, Mississippi, U.S.A., is described and identified as Xiphiorhynchus cf. X. eocaenicus. The specimen is compared to various species of Xiphiorhynchus, especially the holotype of X. eocaenicl.ls (BMNH 25744), Braeklesham Group, early middle Eocene, England. This represents the first record of a species of Xiphiorhynchl.ls in deposits on both sides of the North Atlantic Ocean. Xiphiorhynchus eocaenicus is thought to have had similar environmental prtoferences and habits as the extant swordfish, Xiphias gladius. Since the swordfish prefers oceanic water and makes transatlantic movements, then distribution of a xiphiorhynchin on both sides of the Atlantic is not unexpected. The environment at Tesheva Creek and the type locality in England were both shallow, nearshore, tropical to subtropical habitats. The holotype was probably transported into shallow water either as stomach contents or by ocean currents, whereas the Tesheva Creek specimen was either the remains of a stranded individual or of an animal that died in shallow water after being impaled.