Coleman 2A

University of Florida Vertebrate Fossil Locality SM001

Location

Coleman 2A is located about 2 miles (3.2 km) northeast of Sumterville, between US Highway 301 and the Federal Correctional Complex Of Coleman in a former limestone quarry operated by Dixie Lime and Stone Corporation, Sumter County, Florida. 28.76º N; 82.05º W.

Age

  • Middle Pleistocene Epoch; late Irvingtonian land mammal age
  • 0.5-0.25 million years ago

Basis of Age

A late Irvingtonian age for Coleman 2A is based on its mixture of species also known from older Irvingtonian (and Blancan in some cases) sites and those primarily known from younger Rancholabrean sites. It thus has the youngest known records for some species, such as Meleagris anza, Arctodus pristinus and Canis armbrusteri, while it has the oldest known records for Didelphis virginiana and Neofiber alleni.

Geology

Martin (1974) provided this description based on communication from former Florida State Museum staff member Robert Allen who excavated the site in 1965: “The opening of the paleosink was approximately 30 yards long and 25 yards wide [27 × 23 m]. Only the upper 8 to 10 feet [2.4-3 m] of sediments filling the sink were exposed [by mining]. Thin alternating beds of two different types appeared: a wet orange-brown clay and a coarse gray-white sand. Although the clay facies appear homogeneous, the sand facies were filled with pebble-to-boulder-sized limestone rubble.”

Depositional Environment

While there are some fish and a few other species, such as the mallard, goose, alligator, and muskrat that indicate the presence of some freshwater habitat near the ancient sinkhole that holds the Coleman 2A fossils, the most common species are all terrestrial. Martin (1974) argued that the area surrounding the sinkholes was predominantly a dry savanna, and Ritchie (1980) stated that most of the birds supported this.

Fossils

The Florida Museum of Natural History collection houses about 5,100 cataloged specimens and about 1,000 additional uncatalogued specimens (primarily vertebrae and broken tortoise shell bones). According to Martin (1974), the original collectors noted some of the fossils represented associated skeletons, although some of these were apparently separated during the curation process. the sediments were screenwashed to recover microvertebrates. Fossils were found in both the clay and sand bands filling the ancient sinkhole. Numerous mandibles and maxillae were recovered, along the a few skulls, and well as many complete limb bones. There was no evidence of waterwear on the bones, little or no evidence of weathering, and only minor amounts of carnivore/scavenger damage.

Complete Faunal Fossil List (Click to view)

Excavation History and Methods

Although the date of discovery and collection is listed as 1966 by Martin (1974) and Ritchie (1980), the original ledger catalogs in the Florida Museum of Natural History give a collection date of August to September 1965. The collectors were predominantly UF paleontology graduate students (Jesse Robertson, Sue Hischfeld, Norm Tessman) and Florida State Museum staff (Robert Allen, Kent Ainslie, David Webb). It is not known how many trips were taken to the site, nor the exact methods employed there. Given the relatively large number of specimens collected in a short period of time, this was most likely a salvage operation of a site soon to be destroyed by mining activities.

As discussed elsewhere on these webpages, prior to 1985 the Florida State Museum used a combination of Roman numerals plus a letter to designate fossil sites, so the name of this site was originally Coleman IIA. There were apparently three Coleman quarries operated by the Dixie Lime and Stone Corporation, of which the first one did not produce any fossils. So there are no "Coleman 1" sites in the museum's collection. Their second quarry contained the Coleman 2A site.

Discussion

The mammalian fauna of Coleman 2A was reviewed by Martin (1974) and the birds by Ritchie (1980). Some additions and corrections to the mammals were made by Webb and Wilkins (1984). The only published paper on a reptile from Coleman 2A is the description of a new species of small tortoise by Auffenberg (1988); this was his last published study dealing with fossils from Florida. The remainder of the reptiles and all of the amphibians and fish remain unstudied. Four new species were named on the basis of Coleman 2A fossils: the aforementioned tortoise Hesperotestudo mlynarksii; two small rodents Sigmodon bakeri and Microtus aratai; and a gray fox Urocyon minicephalus. Until the discovery of the Leisey Shell Pit 1A site in 1983, Coleman 2A had the largest number of specimens of the llama Palaeolama mirifica, and they were the primary basis for Webb’s (1974b) description of this species. Carnivores are quite abundant, especially the new species of fox, the wolf Canis armbrusteri, and the jaguar Panthera onca. In addition to Palaeolama mirifica, the other common large herbivore is the peccary Platygonus cumberlandensis. The most common small mammals are mice from the genus Peromyscus and bats from the genus Myotis. The most common reptiles are tortoises, both the extant gopher tortoises and two extinct species of Hesperotestudo. The most abundant birds are the quail Colinus and the turkey Meleagris. Several animals present at Coleman 2A now live far to the west or north of Florida: the golden eagle Aquila chrysaetos, the jackrabbit Lepus, the hognose skunk Conepatus leuconotus, and the porcupine Erethizon dorsatum. This phenomenon is discussed in detail by Morgan and Emslie (2010).

For over 30 years Coleman 2A was the only known late Irvingtonian locality in Florida. Two additional sites of this age were finally discovered in the 2000s in Hendry County, southwest Florida, the Tri-Britton Site and the La Belle Highway Pit.

The mounted skeletons on permanent display at the Florida Museum of Natural History of a leaping jaguar attacking a running peccary are primarily made using fossils from Coleman 2A.

Sources

  • Original Author: Richard C. Hulbert Jr.
  • Original Completion Date: April 9, 2015
  • Editor(s) Name(s): Natali Valdes
  • Last Updated: June 16, 2015
Scientific References (Click to View)

 

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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