St. Marks River Fauna 49 



Archosargus probatocephalus. The sheepshead is a coastal salt- 

 water and estuary species (Hoese and Moore 1977, Lee et al. 1980). 



Family Sciaenidae 

 Sciaenops ocellatus (Linnaeus) 

 Red Drum 

 Material— Quadrate, UGAMNH2092. 



Remarks — This material compares well with modern examples of 

 Sciaenops ocellatus. It is a coastal saltwater species, but is also 

 associated with estuaries (Hoese and Moore 1977, Lee et al. 1980). 



Family Mugilidae 

 Mugil sp. indet. 

 Material— Vertebrae, UGAMNH2093, UGAMNH2094. 

 Remarks — The available material, while certainly Mugil, could 

 not be referred to a species with confidence. Mugil is a coastal saltwater 

 species (Hoese and Moore 1997, Lee et al. 1980). 



RESULTS AND DISCUSSION 



Chronology and Environment of Deposition 



Of several thousand separate skeletal elements recovered from 

 the St. Marks River, 1,162 were referable to specific taxa. Included 

 are 37 species of mammals, 3 birds, 13 reptiles, 2 amphibians, and 

 9 fish. An additional 23 species of birds were identified from the 

 1972 collection made by Storrs Olson. Of all species we reported, 

 14 mammals and 2 reptiles are restricted to the Pleistocene. The 

 remaining are representative of the modern extant regional fauna. 

 With the exception of modern contaminants, the latter are acceptable 

 Pleistocene species; however, they more probably represent a mixture 

 of Holocene and Pleistocene material. This is reflected in the range 

 of mineralization observed in many species. In all cases those species 

 known only from the Pleistocene are well mineralized. However, 

 several species with both a Pleistocene and Recent occurrence such 

 as horse and deer exhibit both well mineralized and, what appears 

 to be, very recent unmineralized condition. Modern contaminants such 

 as cow and pig are unmineralized. In general, mineralization is no 

 criterion of Pleistocene deposition. The problem of apparent 

 heterochronous deposition and separation of Pleistocene and Holocene 

 materials is exacerbated by the apparent rapid mineralization that 

 can occur in reducing environments. Neill (1957) noted that rapid 

 mineralization of organic remains in Florida creates the illusion that 

 Recent material is of older age. Nonetheless, the St. Marks River 



