The Polk County paleontological sites are assemblages of

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of ...

vertebrates occurring in

Polk County, Florida Polk County is located in the central portion of the U.S. state of Florida. The county population was 725,046, as of the 2020 census. Its county seat is Bartow, and its largest city is Lakeland. Polk County comprises the Lakeland–Winter Ha ...

, United States.

Age

Era An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth. Comp ...

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

, ~17.7—1.5 Mya. (calculates to a period of approximately ).

Faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by conventi ...

Hemingfordian The Hemingfordian on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 20,600,000 to 16,300,000 years BP. It is usually considered to overlap the lates ...

through early

Clarendonian The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 13,600,000 to 10,300,000 years BP, a period of . It is u ...

Geological Formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Bone Valley Formation The Bone Valley Formation is a geologic formation in Florida. It is sometimes classified as the upper member of the Peace River Formation of the Hawthorn Group. It contains economically important phosphorite deposits that are mined in west-central ...

Sites

Polk County can boast more individual fossil recovery sites than any other Florida county due to the

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

mining concerns.

is a prime geologic formation. Some of these sites are: Agricola Road ( AEO), Agrico Pierce Mine (AEO), American Agricultural Chemical Company Mine, Brewster Phosphate Mine, Fort Meade Mine,Uhen, Mark D., Collection authority and researcher, George Mason University, Assistant Term Professor, Evolution of cetaceans and other marine mammals Kingsford Mine, Phosphoria Mine, Fort Green Mine, Payne Creek Mine, and Palmetto Mine.
Coordinates:

Specimens

Reptiles

*''

Caretta caretta The loggerhead sea turtle (''Caretta caretta'') is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around in carapace length when fully ...

'' (loggerhead sea turtle) *''

Chelonia The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the family Cheloniidae. It is the only species in the genus ''Chelonia''. Its range exten ...

'' (green sea turtle) *†''

Gavialosuchus ''Gavialosuchus'' is an extinct genus of gavialid crocodylian from the early Miocene of Europe. Currently only one species is recognized, as a few other species of ''Gavialosuchus'' have since been reclassified to other genera. Taxonomy The typ ...

americana'' (American crocodile) *'' Lepidochelys'' and ''L. sensu lato'' (ridley sea turtle)

Mammals

*†''

Acritohippus ''Acritohippus'' is an extinct genus of equine Equinae is a subfamily of the family Equidae, which have lived worldwide (except Indonesia and Australia) from the Hemingfordian stage of the Early Miocene (16 million years ago) onwards. They ...

isonesus'' (horse) *†''

Aelurodon ''Aelurodon'' is an extinct canid genus of the subfamily Borophaginae which lived from the Barstovian land mammal age () of the middle Miocene to the late Miocene epoch ().Agriotherium ''Agriotherium'' is an extinct genus of bears whose fossils are found in Miocene through Pleistocene-aged strata of North America, Europe, Africa, and Asia. This long-lived genus persisted from at least ~11.6–2.5 Mya. Materials from the late ...

schneideri'' (bear) *†''

Aphelops ''Aphelops'' (Greek: "smooth" (apheles), "face" (ops), in a reference of lacking a horn) is an extinct genus of hornless rhinoceros endemic to North America. It lived from the Middle Miocene to the early Pliocene, during which it was a common com ...

malacorhinus'' (rhinoceros) *†'' Arctodus pristinus'' (short-faced bear) *''

Arvicolinae The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae (comprising the hamsters and New World rats and mice). Some authorities place ...

'' (mole, shrew) *†''

Astrohippus ''Astrohippus'' ("Star horse") is an extinct member of the Equidae tribe Equini, the same tribe that contains the only living equid genus, '' Equus''. Fossil remains have been found in the central United States, Florida, and the Mexican states o ...

stockii'' (horse) *†''

Balaenoptera ''Balaenoptera'' () is a genus of rorquals containing eight extant species. ''Balaenoptera'' comprises all but two of the extant species in its family (the humpback whale and gray whale); the genus is currently polyphyletic, with the two aforem ...

floridana'' (

rorqual Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin wha ...

) *†''

Blarina The genus ''Blarina'' is a group of relatively large shrews with relatively short tails found in North America. They have 32 teeth and are in the red-toothed shrew subfamily. They generally have dark fur and thick feet. The saliva of these anim ...

carolinensis'' (shrew) *†''

Borophagus ''Borophagus'' ("gluttonous eater") is an extinct genus of the subfamily Borophaginae, a group of canids endemic to North America from the Middle Miocene epoch through the Early Pleistocene epoch 12—1.8 Mya. Evolution ''Borophagus'', like o ...

hilli'' and ''B. pugnator'' (proto-dog) *†'' Calippus emsliei'' and ''C. cerasinus'', ''C. martini, C. proplacidus'' (horse) *†'' Callophoca obscura'' (earless seal) *†''

Camelidae Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas, ...

'' (camel unknown) *†''

Carpocyon ''Carpocyon'' is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived from the Middle to the Late Miocene, 13.6 to 5.3 Ma Mya, existing for approximately . The four species in the genus varied in size, with ...

limosus'' (Canidae) *†''

Catagonus ''Catagonus'' is a genus of peccaries that contains the living Chacoan peccary and several extinct species. The genus has always been restricted to South America. Taxonomy ''Catagonus'' is notable in that the type species, '' C. metropolitanus'' ...

brachydontus'' (peccary) *†''

Cervidae Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

'' (deer) *†''

Corystosiren ''Corystosiren'' is an extinct genus of dugongid sirenian mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding ...

varguezi'' (sea cow) *†''

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...

'' (vole or lemming) *†''

Cuvieronius ''Cuvieronius'' is an extinct New World genus of gomphothere, named after the French naturalist Georges Cuvier. Alive, specimens typically stood about tall at the shoulder, weighed about and would have superficially resembled a modern elephant ...

tropicus'' (proto-elephant) *†''

Dasypus bellus ''Dasypus bellus'', the beautiful armadillo, is an extinct armadillo species Endemism, endemic to North America and South America from the Pleistocene, living from 1.8 Annum, mya—11,000 years ago, existing for approximately . Slightly larger t ...

'' (beautiful armadillo) *†'' Delphinodon'' and ''D. mento'' (proto-dolphin) *†''

Dinohippus ''Dinohippus'' (Greek: "Terrible horse") is an extinct equid which was endemic to North America from the late Hemphillian stage of the Miocene through the Zanclean stage of the Pliocene (10.3—3.6 mya) and in existence for approximately . Fossi ...

mexicanus'' (horse) *'' Didelphidae'' (opossum) *†'' Enhydritherium terraenovae'' (

mustelid The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in ...

)

*†''

Epicyon ''Epicyon'' ("more than a dog") is a large, extinct, canid genus of the subfamily Borophaginae ("bone-crushing dogs"), native to North America. ''Epicyon'' existed for about from the Hemingfordian age of the Early Miocene, to the Hemphillian of ...

haydeni'' (proto-dog) *†''

Eremotherium ''Eremotherium'' (from Greek for "steppe" or "desert beast": ἔρημος "steppe or desert" and θηρίον "beast") is an extinct genus of giant ground sloth, in the family Megatheriidae, the largest and most heavily built family of sloths. ...

eomigrans'' (giant ground sloth) *†''

Equidae Equidae (sometimes known as the horse family) is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. All extant species are in the genus '' Equus'', ...

'' (horse) *†'' Equus leidyi'' (horse) *†''

Felis ''Felis'' is a genus of small and medium-sized cat species native to most of Africa and south of 60° latitude in Europe and Asia to Indochina. The genus includes the domestic cat. The smallest ''Felis'' species is the black-footed cat with a he ...

rexroadensis'' (wildcat) *''

Geomys The genus ''Geomys'' contains 12 species of pocket gophersSearch results for "''Geomys''" on thASM Mammal Diversity Database often collectively referred to as the eastern pocket gophers. Like all pocket gophers, members of this genus are fossori ...

pinetis'' (gopher) *†''

Gomphotherium ''Gomphotherium'' (; "welded beast") is an extinct genus of proboscids from the Neogene and early Pleistocene of Eurasia, Africa, North America and Asia. As of 2021, two species, ''G. annectens'' and possibly ''G. subtapiroideum'', are also kno ...

obscurum'' (proto-elephant) *†''

Goniodelphis ''Goniodelphis hudsoni'' is an extinct iniid river dolphin known from the waters of Florida during the Miocene ~14.9—11.5 through 9.1—8.7 Ma ( AEO). The fossil specimens were found in just four phosphate mines in Polk County, Florida. These ...

hudsoni'' (river dolphin) *†''

Hadrodelphis ''Hadrodelphis'' is an extinct genus of dolphin once assigned to the paraphyletic/polyphyletic family Kentriodontidae. Remains have been found in the middle Miocene (Langhian) Calvert Formation of United States. Taxonomy ''Harodelphis'' is simil ...

'' (toothed whale) *†''

Hemiauchenia ''Hemiauchenia'' is a genus of laminoid camelids that evolved in North America in the Miocene period about 10 million years ago. This genus diversified and moved to South America in the Early Pleistocene, as part of the Great American Biotic In ...

macrocephala'' (camel) *†''

Heteromyidae Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within the gen ...

'' (kangaroo rat) *†''

Hexameryx ''Hexameryx'' is an extinct monospecific genus of the artiodactyl family Antilocapridae endemic to North America. It lived during the Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.3 ...

simpsoni'' (antelope) *†''

Hippotherium ''Hippotherium'' is an extinct genus of horse that lived in during the Miocene through Pliocene ~13.65—3.3 Mya, existing for . Species The type species, ''H. primigenius'', is known from Miocene deposits in Europe and the Middle East ...

emsliei,'' ''H. ingenuum,'' and ''H. plicatile'' and ''H. ingenuum'' (horse) *†''

Holmesina ''Holmesina'' is a genus of pampathere, an extinct group of armadillo-like creatures that were distantly related to extant armadillos. Like armadillos, and unlike the other extinct branch of megafaunal cingulates, the glyptodonts, the shell wa ...

floridanus'' (giant Florida armadillo) *†''

Homiphoca ''Homiphoca'' is an extinct genus of earless seals from the Pliocene of South Africa. Taxonomy The type species of ''Homiphoca'', ''H. capensis'', was originally described as a species of the dubious delphinoid ''Prionodelphis'', ''P. capensis' ...

capensis'' (earless seal) *†''

Hypohippus ''Hypohippus'' (Greek: "under" (hypos), "horse" (hippos)) is an extinct genus of three-toed horse, which lived 17–11 million years ago. It was the largest anchitherine equid about the size of a modern domestic horse, at and long. It was a lo ...

affinis'' and ''H. chico'' (horse) *†''

Hypolagus ''Hypolagus'' is an extinct genus of lagomorph, first recorded in the Hemingfordian (early to middle Miocene) of North America. It entered Asia during the early Turolian and spread to Europe not much later, where it survived until the Middle Plei ...

tedfordi'' (rabbit) *†'' Kogiopsis floridana'' (Florida sperm whale) *''

Lepus Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The gen ...

'' (hare) *†''

Lophocetus ''Lophocetus'' ("crested whale") is an extinct genus of dolphin belonging to the clade Delphinida that is known from late Miocene (Tortonian) marine deposits in California and Maryland. Although usually placed in Kentriodontidae, recent studies h ...

'' (dolphin) *†'' Mammut matthewi'' (mastodon) *†''

Mammut americanum A mastodon ( 'breast' + 'tooth') is any proboscidean belonging to the extinct genus ''Mammut'' (family Mammutidae). Mastodons inhabited North and Central America during the late Miocene or late Pliocene up to their extinction at the end of the ...

'' (American mastodon) *†''

Mammuthus A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, ...

hayi'' (mammoth) *†''

Megahippus ''Megahippus'' (Greek: "great" (mega), "horse" (hippos)) is an extinct equid genus belonging to the subfamily Anchitheriinae. As with other members of this subfamily, ''Megahippus'' is more primitive than the living horses. It was very large memb ...

'' (horse) *†''

Megalonyx ''Megalonyx'' (Greek, "large claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America during the Pliocene and Pleistocene epochs. It became extinct during the Quaternary extinction event at the end of the ...

wheatleyi'' (giant ground sloth) *†''

Megantereon ''Megantereon'' was a genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It may have been the ancestor of ''Smilodon''. Taxonomy Fossil fragments have been found in Africa, Eurasia, and No ...

hesperus'' (saber-cat) *†''

Merychippus ''Merychippus'' is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene, 15.97–5.33 million years ago. It had three toes on each foot and is the first horse known to have grazed. Discovery and nami ...

californicus'' ''M. brevidontus'' and ''M. goorsi'' (horse) *†''

Mesoplodon Mesoplodont whales are 16 species of toothed whale in the genus ''Mesoplodon'', making it the largest genus in the cetacean order. Two species were described as recently as 1991 (pygmy beaked whale) and 2002 (Perrin's beaked whale), and marine ...

'' (beaked whale) *†''

Metaxytherium ''Metaxytherium'' is an extinct genus of dugong that lived from the Oligocene until the end of the Pliocene. Fossil remains have been found in Africa, Europe, North America and South America. Generally marine seagrass specialists, they inhabit ...

floridanum'' (Florida sea cow) *''

Microtus ''Microtus'' is a genus of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. About 62 species are placed in the genus. They are stout rodents with short ears, legs and tails. They ea ...

'' (vole) *†''

Mylohyus ''Mylohyus'' is an extinct genus of peccary found in North and Central America. It first evolved during the Late Miocene and became extinct at the end of the Pleistocene, around 12,000 years ago. Six species were known, the most famous being ''M ...

elmorei'' (peccary) *†''

Nannippus ''Nannippus'' is an extinct genus of three-toed horse endemic to North America during the Miocene through Pleistoceneabout 13.3—1.8 million years ago (Mya), living around 11.5 million years. This ancient species of three-toed horse grew up to 3 ...

'' and ''N. westoni'' (horse) *†''

Neohipparion ''Neohipparion'' (Greek: "new" (neos), "pony" (hipparion)) is an extinct genus of equid, from the Neogene (Miocene to Pliocene) of North America and Central America Central America ( es, América Central or ) is a subregion of the Ameri ...

eurystyle'' (horse) *†'' Ninoziphius platyrostris'' (beaked whale) *†''

Nothrotheriops ''Nothrotheriops'' is a genus of Pleistocene ground sloth found in North America, from what is now central Mexico to the southern United States. This genus of bear-sized xenarthran was related to the much larger, and far more famous ''Megatherium ...

texanus'' (giant ground sloth) *''

Odocoileus ''Odocoileus'' is a genus of medium-sized deer (family Cervidae) containing three species native to the Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South Am ...

virginianus'' (white-tailed deer) *''

Ondatra The muskrat (''Ondatra zibethicus'') is a medium-sized semiaquatic rodent native to North America and an introduced species in parts of Europe, Asia, and South America. The muskrat is found in wetlands over a wide range of climates and habitat ...

annectens'' (muskrat) *†''

Ontocetus ''Ontocetus'' is an extinct genus of walrus, an aquatic carnivoran of the family Odobenidae, endemic to coastal regions of the southern North Sea and the southeastern coastal regions of the U.S. during the Miocene-Pleistocene. It lived from 13.6 ...

emmonsi'' (walrus) *†'' Pachyarmatherium leiseyi'' (armadillo) *†''

Palaeolama ''Palaeolama'' () is an extinct genus of laminoid camelid that existed from the Late Pliocene to the Early Holocene (). Their range extended from North America to the intertropical region of South America. Description ''Palaeolama'' were relat ...

mirifica'' (stout-legged llama) *†''

Palaeomerycidae The Palaeomerycidae are an extinct family of ruminants in the order Artiodactyla. Palaeomerycids lived in North America, Europe, Africa and Asia from 33 to 4.9 million years ago (from the Late Eocene to Pliocene epochs), existing for about 28 mi ...

'' (deer ancestor) *†''

Paramylodon harlani ''Paramylodon'' is an extinct genus of ground sloth of the family Mylodontidae endemic to North America during the Pliocene through Pleistocene epochs, living from around ~4.9 Mya–11,000 years ago. It is also known as Harlan's ground sloth. D ...

'' (giant ground sloth) *†''

Platanistidae Platanistidae is a family of river dolphins containing the extant Ganges river dolphin and Indus river dolphin (both in the genus '' Platanista'') but also extinct relatives from marine deposits in the Neogene. The Amazon river dolphin, Yangtze ...

'' (river dolphin) *†''

Phocanella ''Phocanella'' is an extinct genus of earless seal The earless seals, phocids or true seals are one of the three main groups of mammals within the seal lineage, Pinnipedia. All true seals are members of the family Phocidae (). They are some ...

pumila'' (earless seal) *†''

Piscobalaena ''Piscobalaena'' is an extinct genus of cetaceans, which lived from the Middle to Late Miocene epochs (about 11.6 to 5.3 million years ago) in Peru and Florida.Physeteridae'' (sperm whale) *†''

Platygonus ''Platygonus'' ("flat head" in reference to the straight shape of the forehead) is an extinct genus of herbivorous peccaries of the family Tayassuidae, endemic to North and South America from the Miocene through Pleistocene epochs (10.3 million ...

vetus'' (peccary) *†''

Pliocyon ''Pliocyon'' is an extinct genus of bear dogs which inhabited North America during the Middle Miocene 16.0—13.6 Ma, existing for approximately . Fossils have been uncovered in South Florida, Oregon, and western Nebraska Nebraska () is ...

robustus'' (bear-dog) *†''

Plionarctos ''Plionarctos'' is an extinct genus of bear endemic to North America from the Miocene to the Pliocene, ~10.3—3.3 Mya (unit), Mya, existing for about 7 million years. ''Indarctos'' (10.7—9.2 Mya) preceded ''Plionarctos'' by only a few thousan ...

'' (bear) *†''

Pliohippus ''Pliohippus'' (Greek (, "more") and (, "horse")) is an extinct genus of Equidae, the "horse family". ''Pliohippus'' arose in the middle Miocene, around 15 million years ago. The long and slim limbs of ''Pliohippus'' reveal a quick-footed stepp ...

mirabilis'' (horse) *†'' Pomatodelphis bobengi'' and ''P. inaequalis'' (river dolphin) *†''

Proboscidea The Proboscidea (; , ) are a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. From ...

'' (elephant, unknown) *†''

Procyonidae Procyonidae is a New World family of the order Carnivora. It comprises the raccoons, ringtails, cacomistles, coatis, kinkajous, olingos, and olinguitos. Procyonids inhabit a wide range of environments and are generally omnivorous. Character ...

'' (raccoon) *†''

Protohippus ''Protohippus'' is an extinct three-toed genus of horse. It was roughly the size of a modern donkey. Fossil evidence suggests that it lived during the Late Miocene (Clarendonian to Hemphillian), from about 13.6 Ma to 5.3 Ma. Analysis of ''Proto ...

perditus'' and ''P. supremus'' (horse) *†''

Pseudhipparion ''Pseudhipparion'' is an extinct genus of three-toed horse endemic to North America during the Miocene. They were herding animals whose diet consisted of C3 plants. Fossils found in Georgia and Florida Florida is a state located in the ...

curtivallum'' and ''P. skinneri'' (horse) *†''

Rhynchotherium ''Rhynchotherium'' is an extinct genus of proboscidea endemic to North America and Central America during the Miocene through Pliocene from 13.650 to 3.6 Ma, living for approximately . This gomphothere had two tusks and may have evolved from ...

'' (proto-elephant) *†''

Scalopus The Eastern Mole or Common Mole (''Scalopus aquaticus'') is a medium-sized North American mole. It is the only member of genus ''Scalopus''. It is found in forested and open areas with moist sandy soils in northern Mexico, the eastern United ...

aquaticus'' (mole or shrew) *†'' Sigmodon libitinus'' (cotton rat) *†'' Sphenophalos garciae'' (antelope) *''

Sylvilagus Cottontail rabbits are the leporid species in the genus ''Sylvilagus'', found in the Americas. Most ''Sylvilagus'' species have stub tails with white undersides that show when they retreat, giving them their characteristic name. However, this ...

floridanus'' and ''S. palustris'' (rabbit) *†''

Talpidae The family Talpidae () includes the moles (some of whom are called shrew moles and desmans) who are small insectivorous mammals of the order Eulipotyphla. Talpids are all digging animals to various degrees: moles are completely subterranean a ...

'' (mole or shrew) *†''

Tapirus ''Tapirus'' is a genus of tapir which contains the three living American tapir species. The Malayan tapir is usually included in ''Tapirus'' as well, although some authorities have moved it into its own genus, ''Acrocodia''. Extant species The ...

haysii'', and ''T. polkensis'' (tapir) *†'' Tayassuidae'' (peccary) *†''

Teleoceras ''Teleoceras'' (Greek: "perfect" (teleos), "horn" (keratos)) is an extinct genus of grazing rhinoceros. It lived in North America during the Miocene and Pliocene epochs during the Hemingfordian to the end of Hemphillian from around 17.5 to 4.9 mi ...

proterum'' (rhinoceros) *''

Ziphiidae Beaked whales (systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well-kn ...

'' (beaked whale)

Notation

The

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

listed within this article were compiled from numerous collections within

Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ...

br>
authorized by John Alroy, John Alroy, Ph.D. Further documentation on these genera and species are available.

References

{{reflist
Evolution of River Dolphins
*G. S. Morgan. 1994. Miocene and Pliocene marine mammal faunas from the Bone Valley Formation of central Florida. Contributions in Marine Mammal Paleontology Honoring Frank C. Whitmore Jr., Proceedings of the San Diego Society of Natural History 29:239-268 Paleontological sites of Florida Natural history of Florida Geography of Polk County, Florida