The world’s oldest fossil seal record

Cajus Diedrich

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DOI: 10.4236/ns.2011.311117                

Abstract

A femur fragment with an Early Lutetian (early Middle Eocene) age is the world’s oldest fossil record from a seal, and, is described as Praephoca bendullensis nov. gen. nov. spec. This find pushes back the earliest evolution of seals into the Paleocene epoch. The femur has plesiomorphic terrestrial mammal characteristics but has a morphology that is already closer to that of Miocene and present day seals. The Eocene seal femur was found at Fürstenau-Dalum in north-west Germany, in a conglomerate rich in shark teeth that was deposited in a coastal delta environment to the north-west of the central European Rhenish Massif mainland, in the southern pre-North Sea Basin. This discovery has led to a revision of the theory that phocids originated along the coastline of the North American continent. Instead they can now be interpreted to have originated in the tropical Eocene climate of central Europe. Although the fossil records of pinnipeds in Europe during the Eocene, Oligocene and Miocene are extremely sparse, they appear to have inhabited the pre- North Sea basin, within the influence of temperate and arctic upwellings. The distribution of abundant teeth from white and megatooth sharks of two different lineages appears to correlate with that of the seals, which the sharks most probably hunted; providing supporting evidence that the phocids were already adapted as shallow marine coastal inhabitants by this time.

Keywords

Oldest Seal Remains; Praephoca bendullensis Nov. Gen. Nov. Spec.; Giant Shark Predation; Middle Eocene; Shallow Marine Coastal Deltaic Influenced Habitats; Pre-Northsea Basin of Central Europe

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Koretsky, I. and Sanders, A.E. (2002) Paleontology of the late oligocene ashley and chandler bridge formations of South Carolina, 1: Paleogene pinniped remains; the oldest known seal (Carnivora: Phocidae). Smithson. Contributions to Paleobiology, 93, 179-183.
[2]	Rybczynski, N., Dawson, M.R. and Tedford, R.H. (2009) A semi-aquatic Arctic mammalian carnivore from the Miocene epoch and origin of Pinnipedia. Nature, 458, 1021-1024. doi:10.1038/nature07985
[3]	Arnason, U., Gullberg, A., Janke, A., Kullberg, M., Lehman, N., Petrov, E.A. and V?in?l?, R. (2006) Pinniped, phylogeny and a new hypothesis for their origin and dispersal. Molecular and Phylogenetic Evolution, 41, 345- 354. doi:10.1016/j.ympev.2006.05.022
[4]	Fulton, T.L. and Strobeck, C. (2010) Multiple markers and multiple individuals refine true seal phylogeny and bring molecules and morphology back in line. Proceedings of the Royal Society B, 277, 1065-1070. doi:10.1098/rspb.2009.1783
[5]	Diedrich, C. (2011) Early Eocene (Lutetian) coastal shark-rich palaeoenvironments of the southern European North Sea Basin—The marine Fürstenau Fm biodiversity and their earliest white shark ancestors. International Journal of Oceanography, in press.
[6]	Ray, C.E. (1977) Geography of phocid evolution. Systematic Zoology, 25, 391-406. doi:10.2307/2412513
[7]	Koretsky, I.A. and Barnes, L.B. (2006) Pinniped evolutionary history and palaeogeography. In: Csiki, Z., Ed., Mesozoic and Cenozoic Vertebrates and Paleoenvironments—Tribute to the career of Professor Dan Grigorescu, 143-153.
[8]	Schaal, S. and Ziegler, W. (1988) Messel—Ein schaufenster in die geschichte der erde und des Lebens: Waldemar Kramer, Frankfurt a. M.
[9]	Franzen, J.L. and M?rs, T. (2007) Das n?rdlichste Vorkommen pal?ogener S?ugetiere in Europa. Pal?onto- logische Zeitschrift, 81, 447-456.
[10]	Friant, M. (1947) Recherches sur le fémur des Phocidae. Bulletin du Musée Royal d’Histoire Naturelle Belgique, 23, 1-51.
[11]	Ericson, P.G.P. and Stor?, J. (1999) A manual to the skeletal measurements of the seal genera Halichoerus and Phoca (Mammalia: Pinnipedia). Department of Vertebrate Zoology, Swedish Museum of Natural History, Stencil, Stockholm.
[12]	Springhorn, R. (1984). Das Oligoz?n in Ostwestfalen- lippe. Lippische Mitteilungen für Geschichte und Lande- skunde, 53, 253-169.
[13]	Koretsky, I.A., Ray, C.E. and Peters N. (2011) Miocene seals of the Netherlands part I: A new species of Leptophoca (Carnivora, Phocidae, Phocinae) from both sides of the North Atlantic Ocean. In: Jacobs, B. and Taylor, L.H., Eds., Paleontologica Electronica, Tribute to the career of Charles Repenning, in press.
[14]	Koretsky, I.A. and Peters, A.M.M. (2008) Batavipusa (Carnivora, Phocidae, Phocinae): A new genus from the eastern shore of the North Atlantic Ocean (Miocene seals of the Netherlands, part II). Deinsea, 12, 53-62.
[15]	Ginsburg, L. and Janvier, P. (1999) Les Phoques (Phocidae, Pinnipedia, Carnivora, Mammalia) des Faluns Miocène de l’Anjou. Bulletin de la Societé Sciences Naturelle l’Ouest France N.S., 21, 169-178.
[16]	Koretsky, I.A. and Ray, C.E. (2008) Phocidae of the Pliocene of Eastern North America. Virginia Museum of Natural History Special Publications, 14, 81-139.
[17]	Burns, J.J. (2002) Harbor seal and spotted seal Phoca vitulina and P. largha. In: Perrin, W.F., Wursig, B. and Thewissen, J.G.M., Eds., Encyclopedia of Marine Mammals, Academic Press, London, 552-560.
[18]	Thompson, D., Hammond, P.S., Nicholas, K.S. and Fedak, M.A. (2009) Movements, diving and foraging behaviour of grey seals (Halichoerus grypus). Journal of Zoology, 224, 223-232. doi:10.1111/j.1469-7998.1991.tb04801.x
[19]	Ziegler, P.A. (1999) Geological atlas of Western and Central Europe. Shell, Amsterdam.
[20]	Lériche, M. (1906) Contribution à lètude des poisons fossils du Nord de la France et des regions voisines. Mémoires de la Société geologique Nord, 5, 1-430.
[21]	Casier, E. (1966) Fauna ichthyologique du London Clay. British Museum Natural History London, 1966, 1-496.
[22]	Van den Eeckhaut, G. and De Schutter, P. (2009) The Elasmobranch fauna of the Lede Sand Formation at osterzele (Lutetian, Middle Eocene of Belgium). Palaeofocus, 1, 1-57.
[23]	Kimley, A.P. and Ainley, D.G. (1996). Great white sharks: The biology of Carcharodon carcharias. Academic Press, San Diego.
[24]	Zalmout, I.S., Ul-Haq, M. and Gingerich, P.D. (2003) New species of Protosiren (Mammalia, Sirenia) from the Early to Middle Eocene of Balochistan (Pakistan). Contributions of the Museum Paleontology University Michigan, 31, 79-87.
[25]	Thewissen, J.G.M. (1998) The emergence of whales: Evolutionary patterns in the origin of Cetacea.