Gainesville Creeks Fauna

University of Florida Vertebrate Fossil Localities AL028M, AL059Hh, AL060, AL068, AL097, AL098, AL099, AL100, AL102, AL107, AL108, AL111, AL113, AL128, AL140, AL146, AL149, AL152, AL156, AL157, and AL158

Location

Most sites are in the northwestern region of Gainesville, Alachua County, Florida, in a region bound by NW 13th Street on the east, by NW 43rd Street on the west, by NW 8th Avenue on the south, and by NW 53rd Avenue on the north. Hogtown, Gainesville High School, Possum, and Rattlesnake creeks have produced the majority of known specimens. However a few sites are located outside this region, including creeks on the University of Florida campus and Little Hatchet Creek in northeast Gainesville.

Age

Basis of Age

Vertebrate biochronology. Based on a characteristic suite of species of equids that compare most favorably with those from the McGehee Farm and Haile 19A sites, whose early Hemphillian age is well constrained (Tedford et al., 2004; Hulbert and Whitmore, 2006).

Geology

Phosphatic sands and clays referred to the Coosawhatchie Formation of the Hawthorn Group (Scott, 1988).

Depositional Environment

A shallow, nearshore marine environment based on very abundant fossils of marine animals such as sharks, rays, cetaceans, and dugongs. Although most specimens are isolated and frequently waterworn or broken, a few complete, articulated skeletons of dugongs and small cetaceans suggest a low energy depositional environment. Terrestrial late Miocene vertebrates are relatively rare and consist mostly of isolated horse teeth.

Fossils

Excavation History and Methods

Collection of vertebrate fossils from creek beds and banks in the Gainesville region dates back to at least the 1920s. No large-scale, professional excavations have ever been done. Most specimens in the FLMNH collection were donated by avocational or amateur collectors. The Florida Museum of Natural History has about 600 specimens in its collection from the Gainesville Creeks.

Discussion

Small creeks in the Gainesville area flow through and erode away sediments of a mix of ages, including early Miocene, late Miocene, and Pleistocene. Most fossils are recovered from modern stream deposits, especially after heavy rains. The bones of modern animals, including raccoon, possum, and domestic cat, as well as discarded items from human meals (chicken bones, BBQ ribs, etc.) are also present, but can usually be distinguished from the true fossils by their unmineralized condition. Fossils of late Miocene age are the most common, especially shark teeth and partial ribs of the extinct dugong Metaxytherium. Such fossils have been found at least 25 different localities in the Gainesville region. In August 2019 Alachua County banned fossil collecting in the Gainesville Creeks.

Most of the fossils found in the Gainesville Creeks have minimal scientific value. Larger samples of the same species have been found in the Peace River and the phosphate mines of Polk and surrounding counties. Likewise, better and more numerous specimens of the same species of land vertebrates can be found in the major late Miocene quarry sites in the western part of Alachua County, such as the Love Bone Bed, McGehee Farm, and Haile 19A. For that reason the specimens of from the Gainesville Creeks have received relatively little scientific attention. There are a couple of notable exceptions, such as a nearly complete skeleton of Metaxytherium floridanum found in the bank of a small creek near Gainesville High School. Also, the Gainesville Creeks is one of the few places in Florida to produce specimens of the extinct leatherback seaturtle Psephophorus.

Sources


This material is based upon work supported by the National Science Foundation under Grant Number CSBR 1203222, Jonathan Bloch, Principal Investigator. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

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