Note: this site is under construction and not completed. Text subject to change. Images to be added soon!

THE PEACE RIVER PALEO PROJECT (PRiPP)

LEAD INVESTIGATORS: MACKENZIE T. ROSS^1,2 & RICHARD C. HULBERT JR.²
COLLABORATORS: BRUCE J. MACFADDEN², LARISA R. G. DESANTIS³ & Others TBD

¹Department of Geological Sciences, University of Florida
²Florida Museum of Natural History, University of Florida
³Department of Biological Sciences, Vanderbilt University

Outline

I. Introduction
II. Composition and Age of Peace River Basin Vertebrate Fossils
A. The Upper Peace River Fauna
B. The Lower Peace River Fauna
III. The Peace River Paleo Project
A. Research
B. Education
C. Outreach
D. Donations and Specimens needed for Study
IV. Chronology and Summary of Primary Scientific Publications on the Vertebrate Fossils of the Peace River
V. List of Donors of PRB Specimens
VI. References Cited

Introduction

The Peace River Paleo Project is a multi-year effort to thoroughly study the vertebrate fossils from the Peace River and its associated tributaries. The land area drained by the Peace River and its tributaries is called the Peace River Basin (PRB) which covers about 1400 sq. miles in south-central Florida This Google Map cannot be loaded because the maps API does not appear to be loaded. The river originates in central Polk County and flows in a generally south to southwest direction for about 100 miles to its mouth in Charlotte Harbor. The vast majority of the recovered fossils are collected in either Hardee or De Soto Counties by members of the general public, not by professional paleontologists. Annually, thousands of vertebrate fossils are recovered from the PRB by many hundreds of individuals under the authorization of collecting permits issued by the State of Florida. While many of these are Floridians, others travel from across the U.S. and even from other countries to hunt for fossils in the PRB.

This project will include specimens both in museum collections, primarily acquired by donated from “amateur” collectors, and those in private collections. In addition to technical scientific publications, the outcomes of the project are expected to include a substantial amount of public outreach and support for K-12 education. Types of outreach may include, but are not limited to, internet sites, public lectures to fossil clubs, at museum events, and on the Florida Museum’s YouTube channel, identification guides, freely available 3D scans of specimens that can be 3D printed, fossil identification events, and more. We will work with K-12 educators, especially those in Hardee, De Soto, and surrounding counties to provide them with real and virtual fossils, data, and expertise that they can use to generate grade-appropriate lesson plans for the classes they teach.

Provisional project timeline:

Fall 2020 Semester: identification and curation of uncataloged PRB specimens in Florida Museum of Natural History (FLMNH) collection (MTR and RCH).

Spring 2021 Semester: scanning of specimens and dietary analysis of PRB herbivores in FLMNH collection (MTR and LRGD); measuring, imaging, and writing descriptions of FLMNH specimens (RCH and MTR); rare earth elements and strontium isotope analysis of PRB specimens (MTR and BJM).

Summer 2021 & Fall 2021 Semester 2021: measuring, scanning, imaging and writing descriptions of fossils in private collections and those donated (MTR and RCH); dietary analysis of PRB herbivores in private collections (MTR and LRGD); production of PRB content for FLMNH web site (RCH and MTR); presentation(s) at the annual meeting of the Society of Vertebrate Paleontology (or alternatively GSA); meet with regional K-12 educators.

Spring 2022 Semester: complete analyses, finish writing scientific papers, and submit for publication; presentations at the annual meeting of the Southeastern Section of the Geological Society of America; public lectures; complete identification guides for PRB fossils. (Some of these may extend into the Summer 2022 Semester.)

Composition and Age of Peace River Basin Vertebrate Fossils

Most of the vertebrate fossils from the Peace River Basin (PBR) are collected from modern sand and gravel bars on the bed of the Peace River and some of its tributary creeks. The fossils are freed by erosion from the sediments or rocks making up the bed and banks of the river, especially during floods when the river’s current is greatly increased. The fossils move downstream with sand and gravel until the current slows down to the point that they stop moving. This cycle of repeated erosion, transport downstream, and deposition results in fossil assemblages that are mixed with the bones of modern animals and man-made objects such as bottles.

More rarely, the fossils are found “in place” in the original sediment that buried them. These sites can be submerged, for example Peace River 3A, or in the dry bank, for example the Harrison Ranch locality. In a few instances, Miocene specimens have been found embedded in rocks of the Peace River Formation.

Since the pioneering works of Sellards (1915a; 1916b), it has long been recognized that the vertebrate fossils of the PBR belong to more than one geologic age. In the following discussion, fossils collected from the open pit phosphate mines in Polk and western Hardee Counties are not included; only those from the bed and banks of the Peace River and its tributaries. Using the currently accepted biochronologic ranges for vertebrate species during the Neogene and Quaternary of North America (Tedford et al., 2004; Bell et al., 2004), almost all the vertebrate fossils recovered from the PBR fall into just two time intervals, late Miocene and late Pleistocene. These specimens make up the Lower Peace River Fauna and the Upper Peace River Fauna, respectively. Early Pleistocene (Blancan) fossils have been found at a location on one of the creeks in the PBR and at least one middle Miocene specimen (UF/TRO 32000), a tooth of a merychippine equid, was collected in the Peace River near Gardner in Hardee County.

The Upper Peace River Fauna

The currently known make-up of the Upper Peace River Fauna is listed in Table 1, along with the number of assigned catalog numbers in the vertebrate paleontology collections of the Florida Museum of Natural History. These numbers provide some indication of the relative abundance of each species. However, donations for fossils of rare species are more likely than those of common ones, so numbers for rare species are likely inflated to some degree. Also, species whose individuals each have large numbers of osteoderms can have inflated numbers over those that do not. There is also a clear bias against animals with small body size in the fauna.

Table 1. Composition of the Upper Peace River Fauna. Number of specimens counts only those in the Florida Museum of Natural History vertebrate paleontology collections.

The Upper Peace River Fauna clearly belongs to the Rancholabrean Land Mammal Age based on the presence of Bison, as the occurrence of that genus in North American fossil sites south of latitude defines that age (Bell et al., 2004). Other species in the fauna that are characteristic of the Rancholabrean include Glyptotherium floridanum, Neofiber alleni, Canis dirus, Urocyon cinereoargenteus, Tremarctos floridanus, Panthera onca, Panthera atrox, and Smilodon fatalis. Two extinct species of Bison are known from the Pleistocene of Florida, Bison latifrons and Bison antiquus. Robertson (1974) proposed that in Florida Bison latifrons was restricted to the early Rancholabrean and Bison antiquus to the late Rancholabrean, and this conclusion was followed by most subsequent researchers. But it is now known that Bison latifrons persisted into the late Rancholabrean in the southeastern United States (Patterson et al., 2012). The two species of Bison co-existed in Florida during the late Rancholabrean, although they have not been recorded together at the same locality and thus may have lived in different habitats. The single Bison horn core from the PBR (UF 266254) belongs to Bison latifrons. For that reason, all the PBR fossils of Bison are listed in the table as that species, although it is possible that some may represent Bison antiquus.

The Lower Peace River Fauna

The Lower Peace River Fauna consists of vertebrate fossils from the PRB that are either collected directly from exposures of the Peace River Formation (sensu Scott, 1988) or, more commonly, from Pleistocene or Holocene alluvial sediments that contain of reworked sediments and fossils from the Peace River Formation. Overall, the Peace River Formation ranges in age from middle Miocene to earliest Pliocene (Scott, 1988; Missimer, 2002). Deposition was not continuous through this interval, as evidenced by wide-spread unconformities. Missimer’s (2002) analysis of sediments and fossils found in the Peace River Formation in Charlotte and Lee Counties demonstrated the presence of numerous coastal and near shore marine environments to a maximum water depth of 20 m (65 ft.).

The most commonly recovered fossils of the Lower Peace River Formation are shark teeth; teeth, dermal “thorns,” and tail spines of rays; and robust elements of nearshore marine bony fish. While the shark teeth are among the most sought after specimens by avocational and recreational collectors, especially those of the larger species, they have never been the subject of a scientific publication. The species listed in Table 2 are based on preliminary identifications and a subject to change as studies progress.

Fossils of marine mammals of this fauna are also fairly common, especially broken pieces of dugong ribs. A small number of whale skulls and mandibles have been collected directly from the Peace River Formation in the bed or lower banks of the Peace River. More fragmentary fossils of whales and dolphins, usually durable teeth or bones such as the auditor bulla and petrosal are found in the river gravel beds. The most common of these are from the genus Pomatodelphis, a dolphin with a very long and narrow rostrum, ear bones of cetotheres, and sperm whale teeth. In Morgan’s (1994) review of Florida marine mammals, this assemblage was characteristic of the middle to early late Miocene. According to Morgan (1994), marine mammals of the late Miocene to early Pliocene in Florida consist of an entirely different array of cetaceans and dugongs along with the addition of phocid seals and the walrus Ontocetus (formerly Trichecodon). None of the cetaceans and dugongs from this assemblage have as yet been collected from the PBR, which suggests that the age of most of the Peace River Formation exposed in the region is early late Miocene (or older). This would correspond to the Tortonian Stage of the geologic time scale, which corresponds to the Clarendonian and early Hemphillian North American Land Mammals Ages.

Fossils of land mammals are rare in the Lower Peace River Fauna, as would be expected from the marine nature of the Peace River Formation in the area. They are much rarer than what is found in the phosphate mines of western Polk and Hardee Counties and eastern Hillsborough and Manatee Counties, which have produced large numbers and diverse faunas of land mammals and reptiles ranging in age from middle Miocene to earliest Pliocene (Sellards, 1915a; 1916b; Simpson, 1930a; Webb and Hulbert, 1986; Webb et al., 2008). All known fossils of land mammals in the Lower Peace River Fauna are isolated and frequently waterworn. Isolated teeth are the most commonly found element, although some postcranial bones are known, including a toe bone from a three-toed horse described in Leidy (1889b). Given the proximity of the Peace River and some of its tributaries to the phosphate mines, it is surprising that none of the recovered PBR specimens belong to species from the latest Hemphillian Palmetto Fauna, which is the most widespread and common terrestrial vertebrate assemblage in the phosphate mines (Webb et al., 2008). Instead they belong to species from the Archer Fauna from north-central Florida of Webb and Hulbert (1986), which ranged from the late Clarendonian to early Hemphillian. This assemblage of species has also been found in what is considered to be a freshwater stream deposit in Nichols Mine in western Polk County.

Therefore, the biochronology of the marine and land mammals of the Lower Peace River Fauna are in agreement that its predominate age is early late Miocene (Tortonian). It is very likely that limited exposures of the Peace River Formation in the PBR are either younger (e.g., Zanclean) or older (middle Miocene) than the Tortonian. This would explain the very rare occurrence of vertebrate fossils from those time intervals in the PBR. Examples are a femur of the seal Callophoca and a tooth a merychippine grade horse, which are mostly likely younger and older than typical members of the fauna, respectively.

Table 2. Composition of the Lower Peace River Fauna. Number of specimens counts only those in the Florida Museum of Natural History vertebrate paleontology collections.

Peace River Paleo Project: Research

We currently plan to complete and publish three studies as part of the PRiPP. All will be published in peer-reviewed, open access journals. We will seek collaborators with special expertise for each study.

1.  Descriptive review of the Upper Peace River Fauna (Pleistocene-aged vertebrates).
2. Descriptive review of the Lower Peace River Fauna (Miocene-aged vertebrates).
3. Multi-proxy analysis of the diet and paleoecology of Upper Peace River Fauna herbivores.

Combined, the two description papers will be the first comprehensive review of Peace River fossils in 130 years.

Donations of additional specimens from the PRB are not necessary to complete the two descriptive studies, but will be welcomed, especially those that add additional species to one of the faunas or that add to our understanding of a particular species. Those who own particularly complete or rare PRB that they do wish donate can still contribute to this project! See the Lists of known species for each fauna are listed above in Tables 1 and 2.

Multi-proxy analysis of the diet and paleoecology of Upper Peace River Fauna herbivores

We will conduct the first such analysis of Peace River mammalian herbivores using the following techniques: stable carbon and oxygen isotopes, microwear, and mesowear. The combination these methods should provide a robust interpretation of the diets of the species under study, and allow us to make inferences about regional ecology and habitats.

Stable carbon and oxygen isotopes derived from tooth enamel (or dentine in case of sloths). Carbon isotopes reveal the relative amounts of plants eaten during the time of tooth mineralization that used C3 photosynthesis (primarily bushes, shrubs, and trees) versus C4 photosynthesis (primarily grasses). Oxygen isotopes reveal information on temperature and precipitation. This method requires destructive sampling of a small portion of the tooth to acquire enamel. To ensure that only adult teeth are sampled, only third molars will be used, except for mammoths and mastodons for which second or third molars can be used. Teeth do not need to be complete for this method, but must preserve sufficient enamel.

Microwear analysis looks at microscopic wear features (pits and scratches) created when an animal chews its food. Size, frequency, and allignment of pits and scratches can distinguish between grazers, browsers, and fruit/seed eaters. Only features formed during last two weeks of life are preserved. Only upper molars will be used in this analysis. Teeth must be very well preserved, so that wear features are preserved and not eroded or worn off. In general, if the roots of isolated teeth are missing, The analysis is done on casts, so that specimens to do not need to be donated to be included in this study, except for deer, bison, and horse teeth which have to be subjected to destructive sampling for rare earth elements.

Mesowear analysis looks at the shape of the occlusal surface of worn teeth in profile. Animals eating low-lying plants with relatively large amounts of dust and grit on them wear their molar teeth flat. Animals eating softer leaves higher off the ground retain occlusal surfaces with ridges and valleys until old age. Only upper molars will be used and must preserve the entire buccal (outer) half of the occlusal surface. Teeth must be well preserved, with no or only minor waterwear. This analysis can be done by quick visual inspection of the tooth and digital images. Specimens do not need to be donated to be included in this study, except for deer, bison, and horse teeth which have to be subjected to destructive sampling for rare earth elements.

Peace River Paleo Project: K-12 Education

Three Major Goals:

1. Fossil Kits with Peace River Fossils for use in K-12 Classrooms
2. Specimens to be scanned and uploaded to open-access platforms for 3D printing in the classroom and beyond (fossil clubs, science clubs, science camps, even at home!)
3. Collaborate with K-12 teachers (especially in Hardee and DeSoto counties) to create paleontology-oriented lesson plans:
   • Measuring fossil teeth (e.g., shark teeth, horse teeth) to study evolution & body size.
   • Osteometry of alligator, turtle, & tortoise limb bones (e.g., femur : tibia)
   • Mesowear lesson plan
   • What the teachers’ come up with!

Peace River Paleo Project: Outreach

Main goals include:

1. Adding photo and/or scanned images of PRB specimens to online collection database.
2. Add 20-25 species accounts to FLMNH web page (e.g., Bison latifrons, Panthera atrox, Hesperotestudo crassiscutata, Galeocerdo aduncus).
3. Utilizing social media to create online identification guides for Peace River fossils.
4. ID fossils in personal collections at home visits by museum staff and students.
5. Organizing virtual events with fossil clubs to determine what you would like to gain from this project!
6. Arranging ADA compliant Peace River field visits for disabled science enthusiasts

Peace River Paleo Project: Donations and Specimens Needed for Study

For the description studies we will gladly accept donations of any PRB specimens, but in particular are in need of specimens that either belong to species not listed above in Tables 1 and 2, or for which we have four or fewer specimens. We can also accept donations of vertebrate fossils from the PRB of lesser quality for school kits and teachers.

In cases where there is a scientifically valuable specimen from the PRB which the owner does not want to donate, we can scan the specimen to create a 3D virtual copy that can be studied and also used for educational purposes. Owners of such specimens should contact rhulbert@flmnh.ufl.edu.

For the dietary and paleoecology project we are need of the following numbers of specimens:

Note that some specimens potentially could be used in two or even all three analyses if they meet the required criteria. An ‘*’ after a species name means that specimens must be destructively sampled for REE to ensure they are fossil and not modern. Otherwise, specimens for microwear and mesowear do not require donation.

Chronology and Summary of Primary Scientific Publications on
the Vertebrate Fossils of the Peace River

• G. W. Rains (1850) reported the recovery of mammoth (“fossil elephant”), mastodon, tortoise (“upper shell of a fossil turtle that averages, perhaps, one inch in thickness”), and megalodon shark teeth from Peace Creek and its tributaries. “So thickly are these fossils strewed along the course of the [Peace Creek] that, in many places its bed is literally paved with their remains…”
• J. Leidy (1882) noted the find of a phalanx and astragalus of an Equus “of ordinary size” on Peace Creek found in association with mammoth and tortoise. The mammoth was later figured (Leidy 1889b, plate 8.2)
• J. Leidy (1889a) gave a brief account of fossils from Peace Creek near Arcadia that include tapir, horse, deer, turtle, shark, and cetaceans [to be more fully described and illustrated in Leidy (1889b). Leidy (1889a) provided a detailed description of a phalanx of a hipparion horse, and named two new species, Glyptodon septentrionalis and Emys euglypha.
• J. Leidy’s (1889b) was his most detailed and illustrated account of the specimens he had previously noted in earlier papers (Leidy, 1882, 1889a). Leidy’s fauna was a mixture of Pleistocene (e.g., mammoth, Equus, Tapirus, tortoise, Megalonyx, etc.) and Miocene (e.g., hipparion equid, dugonids, cetaceans, marine sharks, rays, and bony fish) fossils, but this was not recognized until Sellard’s work in 1915 (see below). One new species was named here, Testudo crassiscutata. The osteoderms previously named as Glyptodon septentrionalis were correctly recognized as being from a pampathere, and Leidy suggested his name was a junior synonym of Chlamydotherium humboldtii of South America. A true glyptodont was recognized from Peace Creek, and referred to Glyptodon petaliferus, a species Cope described from Texas. Several tortoise osteoderms were incorrectly ascribed by Leidy to glyptodonts.
• W. H. Dall (1891) discussed the age of the Peace Creek fossils. According to his observations, “The bones then,—that is those from Peace Creek, which are all derived from one original stratum not over two feet thick,—are older Pliocene beyond any question. I found actually in the bed mastodon, manatee, horse, glyptodont, and big turtle with others I did not recognize.” This determination was based on supposed stratigraphic superposition relationships, lying below Caloosahatchee-equivalent shell beds and overlie older Pliocene phosphatized rock (Peace River Formation).
• F. A. Lucas (1899) was the first to recognize the Peace River bison as the species Bison latifrons.
• O. P. Hay (1913) recognized three species of Equus from the Peace River largely on the basis of size: large (E. fraternus); medium (E. leidyi); and small (E. littoralis). The latter two were new names described in this work. In accepting E. fraternus as the name for the large species (contra Gidley, 1901), Hay concluded that Cope’s (1895) selection of a lectotype for Equus fraternus was technically valid and could not be overturned even if it changed the intent of the original author, as favored by Gidley. Gidley (1901) favored using this species name for the medium-sized Equus from the southeastern US.
• Florida State Geologist E. H. Sellards (1915a) was the first to claim that the fossils from the Peace River are chronologically mixed as a result of reworking. He regarded the fossils of marine fish, shark, and hipparionine equid to be of “Pliocene” age (late Miocene of current usage); while other fossils were regarded as Pleistocene. Unlike Leidy, Hay, and other early researchers, Sellards had personally visited the Peace River and investigated the geology of its beds and banks and collected fossils from the area.
• E. H. Sellards (1915b) demonstrated with more complete material including a dentary from Vero that Leidy’s (1889a) name Glyptodon septentrionalis was not synonymous with Chlamytherium humboltii and was a separate valid species. The combination Chlamytherium septentrionalis was used for the first time. Leidy’s species was later made the type species of a new genus, Holmesina, by Simpson (1930b), although that work did not use any Peace River material.
• E. H. Sellards (1916) made extensive comparisons with the large tortoise Testudo crassiscutata from Peace Creek during his description of Testudo hayi from the Bone Valley.
• O. P. Hay (1923) in his review of Pleistocene vertebrates of eastern North American gave an up-dated faunal list for the Peace River near Arcadia, De Soto County. It included 12 species of Pleistocene mammals: Elephas imperator; Elephas columbi; Mammut americanum; Bison sp.; Odocoileus osceola?; Tapirus terrestris; Equus leidyi; Equus littoralis; Glyptodon petaliferus; Glyptodon rivipacis; Chlamytherium septentrionalis; and Megalonyx jeffersoni. Hay (1923) also listed Megatherium sp. and E. columbi as coming from Zolfo in Hardee County. This assemblage was later repeated by Simpson (1929), but with some changes in systematic nomenclature. Hay regarded all the fossils of mammals and reptiles from the Peace River as contemporaneous and dating to the early Pleistocene (“Aftonian”). Glyptodon rivipacis was briefly described as a new species on the basis of specimens previously studied and figured by Leidy (1889b).
• G. G. Simpson (1929a; 1930a) expressed strong support for Sellard’s (1915a) idea that the Peace River fossils are chronological mixed. In these works, Simpson emphasized the greater integrity of fossils from four land sites that he felt did not have evidence of reworking: Vero, Melbourne, Seminole Field, and Sabertooth Cave. Simpson (1929a) categorized the Peace River vertebrate fauna with other Pleistocene sites from Florida that he regarded as “dubious and inadequate.” Following this designation, research on Peace River fossils decreased greatly.
• W. W. Holmes and G. G. Simpson (1931) listed four xenarthran taxa from the Peace River: Megalonyx jeffersoni, Megatherium sp. (from “Zolfo, Hardee County”), Holmesina septentrionalis, and Boreostracon floridanus. No Peace River species were figured or described. No source or details provided for the Megatherium record (based on catalogued records accessed on-line, this should be AMNH FM 14477). See also p. 38 of Hay (1923).
• S. D. Webb (1974) reviewed the chronology of Florida Pleistocene mammals. Specimens from the Peace River were only briefly mentioned and not included in his table that listed each species found at 41 faunas. Interestingly one of the localities Webb (1974) did include was Joshua Creek, a tributary of the Peace River. The listed fauna from Joshua Creek is far smaller than that listed from the Peace River by Hay (1923) or Simpson (1929a). The likely reason for its inclusion was that Webb had collected in Joshua Creek and personally found some specimens there in 1968.
• J. S. Robertson (1974) listed the Peace River bison specimens in the USNM collection previously studied by Lucas (1899). He regarded them as not diagnostic to the species level, due to the lack of horn cores. At the time of Robertson’s publication, the vertebrate paleontology collection at the Florida Museum of Natural History did not have any bison specimens from the Peace River (currently we have about 70 such specimens).
• D. D. Gillette and C. E. Ray (1981) agreed with Simpson (1929b) that Glyptodon petaliferus Cope 1889 and Glyptodon rivipacis Hay 1923 were not valid species and used the new combination Glyptotherium floridanum (Simpson) for the late Pleistocene glyptodont from Florida and the SE US. Their list of referred specimens included only one specimen from the Peace River, UF 19247, omitting those cited and figured by Leidy (1889b).
• C. E. Ray (2005) provided a detailed history of the discovery of fossils in the Peace River and early research.
• R. C. Hulbert et al. (2009) described the first fossil record of the collared peccary (genus Pecari) from the United States from a submerged, in situ deposit on the Peace River. An additional 33 vertebrate taxa from this locality were listed but not described nor figured. The name of the locality was given as Peace River 5A in Hulbert et al. (2009), but this was based on a mistaken location provided by the collector. The locality’s correct name is Peace River 3A. A second specimen from a different Peace River locality was also referred to Pecari.
• R. C. Hulbert et al. (2014) listed specimens of the giant beaver Castoroides dilophidus from the Peace River in both Hardee and De Soto County, and from one of its tributaries, Prairie Creek. This was the first reported occurrence of this genus from the Peace River.

List of Donors of PRB Fossils

References Cited

Bell, C. J., E. L. Lundelius Jr, A. D. Barnosky, R. W. Graham, E. H. Lindsay, D. R. Ruez Jr., H. A. Semken Jr., S. D. Webb, and R. J. Zakrzewski. 2004. The Blancan, Irvingtonian, and Rancholabrean mammal ages. Pp. 232–314 in M. O. Woodburne (ed.), Late Cretaceous and Cenozoic Mammals of North America. Columbia University Press New York.

Cope, E. D. 1895. On some Plistocene [sic] Mammalia from Petite Anse, La. Proceedings of the American Philosophical Society 34(149):458–468.

Dall, W. H. 1891. On the age of the Peace Creek beds, Florida. Proceedings of the Academy of Natural Sciences of Philadelphia 43:120.

Gidley, J. W. 1901. Tooth characters and revision of the North American species of the genus Equus. Bulletin of the American Museum of Natural History 14(9):91–140.

Gillette, D. D., and C. E. Ray. 1981. Glyptodonts of North America. Smithsonian Contributions to Paleobiology 40:1–255.

Hay, O. P. 1913. Notes on some fossil horses, with descriptions of four new species. Proceedings of the United States National Museum 44:569–594.

Hay, O. P. 1923. The Pleistocene of North America and its vertebrated animals from the states east of the Mississippi River and from the Canadian provinces east of longitude 95°. Carnegie Institution of Washington Publication 322, 499 p.

Holmes, W. W., and G. G. Simpson. 1931. Pleistocene exploration and fossil edentates in Florida. Bulletin of the American Museum of Natural History 59(7):383–418.

Hulbert Jr., R. C., G. S. Morgan, and A. Kerner. 2009. Collared peccary (Mammalia, Artiodactyla, Tayassuidae, Pecari) from the late Pleistocene of Florida; pp. 543–555 in L. B. Albright III (ed.), Papers on Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne. Museum of Northern Arizona Bulletin 65. Flagstaff, Arizona.

Hulbert Jr., R. C., A. Kerner, and G. S. Morgan. 2014. Taxonomy of the Pleistocene giant beaver Castoroides (Rodentia: Castoridae) from the southeastern United States. Bulletin of the Florida Museum of Natural History 53(2):26-43.

Leidy, J. 1882. On remains of horses. Proceedings of the Academy of Natural Sciences of Philadelphia 34:290–293.

Leidy, J. 1889a. Fossil vertebrates of Florida. Proceedings of the Academy of Natural Sciences of Philadelphia 41:96–97.

Leidy, J. 1889b. Description of vertebrate remains from Peace Creek, Florida. Transactions of the Wagner Free Institute of Science of Philadelphia 2:19–31.

Leidy, J. 1890. Hippotherium and Rhinoceros from Florida. Proceedings of the Academy of Natural Sciences of Philadelphia 42:182–183.

Lucas, F. A. 1899. The fossil bison of North America. Proceedings of the U. S. National Museum 21(1172):755–771.

Missimer, T. M. 2002. Late Oligocene to Pliocene evolution of the central portion of the South Florida Platform: mixing of siliciclastic and carbonate sediments. Florida Geological Survey, Bulletin 65:1–184.

Patterson, D. B., A. J. Mead, and R. A. Bahn. 2012. New skeletal remains of Mammuthus columbi from Glynn County, Georgia with notes on their historical and paleoecological significance. Southeastern Naturalist 11(2):163–172.

Rains, G. W. 1850. Geology of Florida. Scientific American 5(21):165.

Ray, C. E. 2005. An idiosyncratic history of Floridian vertebrate paleontology. Bulletin of the Florida Museum of Natural History 45(4):143–170.

Robertson, J. S. 1974. Fossil Bison of Florida. Pp. 214–246 in S. D. Webb (ed.), Pleistocene Mammals of Florida. University Presses of Florida, Gainesville.

Scott, T. M. 1988. The lithostratigraphy of the Hawthorn Group (Miocene) of Florida. Florida Geological Survey Bulletin 59:1–148.

Sellards, E. H. 1915a. The pebble phosphates of Florida. Florida Geological Survey Annual Report 7:25–116.

Sellards, E. H. 1915b. Chlamytherium septentrionalis, an edentate from the Pleistocene of Florida. American Journal of Science 40:139–145.

Sellards, E. H. 1916a. A new tortoise and a supplementary note on the gavial, Tomistoma americana. American Journal of Science 42:235–240.

Sellards, E. H. 1916b. Fossil vertebrates from Florida: a new Miocene fauna; new Pliocene species; the Pleistocene fauna. Florida Geological Survey Annual Report 8:77–119.

Simpson, G. G. 1929a. The extinct land mammals of Florida. Florida State Geological Survey Annual Report 20:229–279.

Simpson, G. G. 1929b. Pleistocene mammalian fauna of the Seminole Field, Pinellas County, Florida. Bulletin of the American Museum of Natural History 56(9):561–599.

Simpson, G. G. 1930a. Tertiary land mammals of Florida. Bulletin of the American Museum of Natural History 59(3):149–211.

Simpson, G. G. 1930b. Holmesina septentrionalis, extinct giant armadillo of Florida. American Museum Novitates 332:1–10.

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