18 Timothy S. Young and Joshua Laerm 



from the main vent. The pH and temperature as measured 16 July 

 1974 were 7.6 and 21. OC, respectively. Newport Spring also feeds 

 the river about 800 m north of the U.S. Highway 98 bridge. The 

 discharge of the spring as measured 2 March 1972 was 0.23 m 3 /sec 

 with a pH of 7.8 and water temperature of 19C (Rosenau et al. 

 1977). 



Primary depositional site(s) were not located. The fossils are 

 probably eroding out of the banks along much of the length of the 

 river and washed down river by the current. Dense accumulations of 

 fossils may be found in sand deposits, around submerged debris, and 

 in deep holes along the entire length of the river. 



The St. Marks River with its shallow, relatively clear waters 

 with abundant fossil and archaeological materials has been a popular 

 recreational S.C.U.B.A. diving are for the past 30 years. Local divers 

 report huge quantities of fossils have been recovered by amateur collectors. 

 One of us (J.L.) observed an entire pick-up truck load of fossils 

 being removed in 1978. Local divers report that have collected "tons 

 of it." Although several large private collections of St. Marks material 

 exist, unfortunately they have been mixed with fossils from other 

 regional aquatic systems which makes their inclusion here 

 inappropriate. 



METHODS 



We made extensive new collections and reviewed previously 

 collected materials housed at the Florida Museum of Natural History, 

 University of Florida (UF), and the National Museum of Natural 

 History (USNM), Washington, D. C. Our collections are housed at 

 the University of Georgia Museum of Natural History (UGAMNH). 

 Collection efforts were concentrated in six separate locations 

 approximately 3.2 km in either direction from the U.S. Highway 98 

 bridge that crosses the St. Marks River (Fig. 1). The fossils were 

 collected from 16 to 19 July 1987 by a team of six people from 

 the University of Georgia using S.C.U.B.A. gear. The majority of 

 the fossil materials was collected by hand from these locations along 

 the river. In addition, extensive sand samples were taken at each 

 site for subsequent screening. 



To preliminarily identify recovered materials we used the 

 Comparative Reference Skeletal Collection of the Zooarchaeology 

 Laboratory, the University of Georgia Museum of Natural History. 

 Reference sources were also used in preliminary identifications. 

 All materials were subsequently taken to the Paleontology 

 Laboratory, the Florida Museum of Natural History, University of 

 Florida, to confirm identifications. Notes were made on the 

 element identified, side, and fusion of bones where possible. 



