| Tapirus merriami Temporal range: Middle-Late Pleistocene | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Perissodactyla |
| Family: | Tapiridae |
| Genus: | Tapirus |
| Species: | †T. merriami |
| Binomial name | |
| †Tapirus merriami Frick, 1921 | |
Tapirus merriami, commonly called Merriam's tapir, is an extinct species of tapir which inhabited North America during the Pleistocene.
Tapirs have a long history on the North American continent. Fossils of ancient tapirs in North America can be dated back to 50 million-year-old Eocene rocks on Ellesmere Island, Canada, which was then a temperate climate. [1] By 13 million years before present, tapirs very much like extant tapirs existed in Southern California. [2]
During the Pleistocene epoch, four species of tapir are known to have inhabited North America. Along with T. merriami, Tapirus californicus also lived in California, Tapirus veroensis was found in Florida, Georgia, Kansas, Missouri and Tennessee, and Tapirus copei was found from Pennsylvania to Florida. [3]
First discovered and described in 1921 by American vertebrate paleontologist Childs Frick, T. merriami lived at the same time, and perhaps many of the same locations, as T. californicus, [4] but is believed to have preferred more inland habitats of southern California and Arizona. Like T. californicus and all living tapirs, it is believed to have been a relatively solitary species. Of the four known Pleistocene-era tapirs found on the North American continent, T. merriami was the largest. [3] T. merriami was a stout-bodied herbivore with short legs, a large, tapering head, and a short, muscular proboscis adept at stripping leaves from shrubs. [5]
Perissodactyla is an order of ungulates. The order includes about 17 living species divided into three families: Equidae, Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). They typically have reduced the weight-bearing toes to three or one of the five original toes, though tapirs retain four toes on their front feet. The nonweight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, artiodactyls bear most of their weight equally on four or two of the five toes: their third and fourth toes. Another difference between the two is that odd-toed ungulates digest plant cellulose in their intestines, rather than in one or more stomach chambers as even-toed ungulates, with the exception of Suina, do.
Ungulates are members of the diverse clade Euungulata which primarily consists of large mammals with hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including equines, rhinoceroses, and tapirs; and Artiodactyla including cattle, antelope, pigs, giraffes, camels, sheep, deer, and hippopotamuses, among others. Cetaceans such as whales, dolphins, and porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. Two other orders of ungulates, Notoungulata and Litopterna, both native to South America, became extinct at the end of the Pleistocene, around 12,000 years ago.
Tapirs are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America and Southeast Asia. They are one of three extant branches of Perissodactyla, alongside equines and rhinoceroses. Only a single genus, Tapirus, is currently extant. Tapirs migrated into South America during the Pleistocene epoch from North America after the formation of the Isthmus of Panama as part of the Great American Interchange. Tapirs were formerly present across North America, but became extinct in the region at the end of the Late Pleistocene, around 12,000 years ago.
The South American tapir, also commonly called the Brazilian tapir, the Amazonian tapir, the maned tapir, the lowland tapir, the anta (Portuguese), and la sachavaca, is one of the four recognized species in the tapir family. It is the largest surviving native terrestrial mammal in the Amazon.
Tapirus is a genus of tapir which contains the living tapir species. The Malayan tapir is usually included in Tapirus as well, although some authorities have moved it into its own genus, Acrocodia.
Litopterna is an extinct order of South American native ungulates that lived from the Paleocene to the end of the Pleistocene-early Holocene around 63 million-12,000 years ago, and were also present in Antarctica during the Eocene. They represent the second most diverse group of South American ungulates after Notoungulata. It is divided into nine families, with Proterotheriidae and Macraucheniidae being the most diverse and last surviving families.
Chalicotherioidea is an extinct superfamily of clawed perissodactyls that lived from the early Eocene to the early Pleistocene subepochs. Based on the fossil record they emerged and thrived largely in Eurasia, although specimens have been found in both Africa and North America. They were likely browsers that fed mainly on leaves, twigs, and other nonresistant vegetation. Many of the contained genera had derived specializations of the forelimb and manus that allowed the claws to be used as hooks for browsing and to be kept off of the ground while walking. Chalicotheres lived primarily in forested areas. Size sexual dimorphism and morphological structures such as the domed skulls of Tylocephalonyx suggest agonistic behaviour in some sort of social setting. They are related to modern day horses, rhinoceroses, and tapirs, as well as the extinct brontotheres.
The genus Hydrochoerus contains two living and three extinct species of rodents from South America, the Caribbean island of Grenada, California and Panama. Capybaras are the largest living rodents in the world. The genus name is derived from the Greek ὕδωρ 'water' plus χοίρος 'pig'.
Notoungulata is an extinct order of mammalian ungulates that inhabited South America from the early Paleocene to the Holocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms resembling animals as disparate as rabbits and rhinoceroses. Notoungulata are the largest group of South American native ungulates, with over 150 genera in 14 families having been described, divided into two major subgroupings, Typotheria and Toxodontia. Notoungulates first diversified during the Eocene. Their diversity declined from the late Neogene onwards, with only the large toxodontids persisting until the end of the Pleistocene, perishing as part of the Quaternary extinction event among with most other large mammals in the Americas. Collagen analysis suggests that notoungulates are closely related to litopterns, another group of South American ungulates, and their closest living relatives being perissodactyls, including rhinoceroses, tapirs and equines as part of the clade Panperissodactyla. However their relationships to other South American ungulates are uncertain. Several groups of notoungulates separately evolved ever-growing cheek teeth.
Macrauchenia was a large, long-necked and long-limbed, three-toed native South American ungulate in the order Litopterna. The genus gives its name to its family, the Macraucheniidae or "robust litopterns". Like other litopterns, it is most closely related to the odd-toed ungulates (Perissodactyla), from which litopterns diverged approximately 66 million years ago. The oldest fossils in the genus date to the late Miocene, around seven million years ago, and M. patachonica disappears from the fossil record during the late Pleistocene, around 20,000-10,000 years ago. M. patachonica is one of the last and best known member of the family and is known primarily from the Luján Formation in Argentina, but is known from localities across southern South America. Another genus of macraucheniid Xenorhinotherium was present in northeast Brazil and Venezuela during the Late Pleistocene. The type specimen was discovered by Charles Darwin during the voyage of the Beagle. In life, Macrauchenia may have resembled a humpless camel, though the two taxa are not closely related. It fed on plants in a variety of environments across what is now South America. Among the species described, M. patachonica and M. ullomensis are considered valid; M. boliviensis is considered a nomen dubium; and M. antiqua has been moved to the genus Promacrauchenia.
Titanis is a genus of phorusrhacid, an extinct family of large, predatory birds, in the order Cariamiformes that inhabited the United States during the Pliocene and earliest Pleistocene. The first fossils were unearthed by amateur archaeologists Benjamin Waller and Robert Allen from the Santa Fe River in Florida and were named Titanis walleri by ornithologist Pierce Brodkorb in 1963, the species name honoring Waller. The holotype material is fragmentary, consisting of only an incomplete right tarsometatarsus and phalanx, but comes from one of the largest phorusrhacid individuals known. In the years following the description, many more isolated elements have been unearthed from sites from other areas of Florida, Texas, and California. It was classified in the subfamily Phorusrhacinae, which includes some of the last and largest phorusrhacids like Devincenzia and Kelenken.
Teratornis was a genus of huge North American birds of prey—the best-known of the teratorns—of which, two species are known to have existed: Teratornis merriami and Teratornis woodburnensis. A large number of fossil and subfossil bones, representing more than 100 individuals, have been found in locations in California, Oregon, southern Nevada, Arizona, and Florida, though most are from the Californian La Brea Tar Pits. All remains except one Early Pleistocene partial skeleton from the Leisey Shell Pit near Charlotte Harbor, Florida date from the Late Pleistocene, with the youngest remains dating from the Pleistocene–Holocene boundary.
Kyptoceras is a small extinct artiodactyl ungulate mammal of the family Protoceratidae, endemic to southeastern North America from the Miocene to Early Pliocene epoch 23.03—3.6 Ma, existing for approximately 19.43 million years. The species name, amatorum, comes in honor of all amateur fossil collectors, including Frank Garcia the amateur who found it and donated it to the Florida Museum of Natural History.
The giant tapir is an extinct species of tapir that lived in southern China, Vietnam and Laos, with reports suggesting it also lived in Taiwan, Java, and potentially Borneo. The species has been recorded from Middle and Late Pleistocene. There is only weak evidence for a Holocene survival. Tapirus augustus was larger than any living tapir, with an estimated weight of about 623 kilograms (1,373 lb). The species was also placed in its own genus of Megatapirus, however, it is now conventionally placed within Tapirus.
The latter half of the Late Pleistocene to the beginning of the Holocene saw extinctions of numerous predominantly megafaunal (large) animal species, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are thought to have been driven by varying combinations of human and climatic factors. Human impact on megafauna populations is thought to have been driven by hunting ("overkill") as well as possibly environmental alteration. The relative importance of human vs climatic factors in the extinctions has been the subject of long-running controversy.
Tapirus californicus, the California tapir, is an extinct species of tapir that inhabited North America during the Pleistocene. It became extinct about 13,000 years ago.
Paleontology in Florida refers to paleontological research occurring within or conducted by people from the U.S. state of Florida. Florida has a very rich fossil record spanning from the Eocene to recent times. Florida fossils are often very well preserved.
Tapirus haysii is an extinct species of tapir that inhabited North America during the early to middle Pleistocene Epoch (~2.5–1 Ma). The fossil remains of two juvenile T. haysii were collected in Hillsborough County, Florida on August 31, 1963. It was the second largest North American tapir; the first being T. merriami.
Tapirus veroensis is an extinct tapir species that lived in the area of the modern eastern and southern United States during the Pleistocene epoch (Irvingtonian-Rancholabrean). Tapirus veronensis is thought to have gone extinct around 11,000 years ago.
Tapirus rondoniensis is an extinct species of large sized tapir that lived in northwestern parts of Brazil during the Pleistocene. Fossils of the species were found in the Río Madeira Formation of Rondônia, after which the species is named.
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