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Pleistocene Mammal Extinctions The late Pleistocene witnessed the extinction of 35 genera of large North American mammals. The last appearance dates of 16 of these genera securely fall between 12,000 and 10,000 radiocarbon years ago (≈13,800–11,400 calendar years B.P.). Whether the absence of fossil occurrences for the remaining 19 genera from this time interval is the result of sampling error or temporally staggered extinctions is unclear. The cause of the extinctions has been exceptionally tricky to resolve in NA because the time of extinction overlaps both a critical one for climate change and the time that the Clovis people flourished, although it is hard to see why a more livable climate would lead to a mass extinction. A short-faced bear Arctodus simus, showing size relative to an adult human. Some weighedover a ton, twice the size of a grizzly bear. There is no question that humans played a role in this ‘mass extinction in a geological instant’ in North America. Archeological sites that illustrate heavy human predation on large mammals in that time period include the 15,000 year old Mezhirich site 90 miles south of Kiev in the Ukraine there are 4 oval shaped dwelling built of 70 tons of mammoth bones from at least 200 kills (mammoths went extinct in Eurasia in the same period). One dwelling has an outer wall composed of 95 mammoth mandibles stacked on top of one another in a herringbone pattern. A site in Czechoslovakia has over 1000 mammoths. . The most spectacular accumulation of all exists at Solutre in France, where at the foot of a steep cliff extensive deposits more than 3 feet thick contain the bones of 10,000 to 100,000 horses, either driven to their deaths off the top of the cliff or ambushed in a narrow pass down below. (fm The Creative Explosion pg 60). In North America there is ample evidence of the heavy toll that Native Americans could take on the large mammals present in more recent times. A stampede of bison 150 miles southeast of Denver drove 190 of the animals over a cliff A wikipedia page titled ‘Buffalo Jumps’ notes that Native Americans “herded the bison and drove them over the cliff, breaking their legs and rendering them immobile. Tribe members waiting below closed in with spears and bows to finish the kills. The Blackfoot Indians called the buffalo jumps "pishkun", which loosely translates as "deep blood kettle". This type of hunting was a communal event which occurred as early as 12,000 years ago and lasted until at least 1500 CE, around the time of the introduction of horses. On all of the continents and islands where Homo sapiens was a recent arrival during the late Pleistocene and Recent Eras, there were die-offs of large animals. A recent dating of the extinction of a large flightless bird in Australia using an amino acid technique on eggshells indicates 50,000 years ago--just when Aborigines arrived. Moas in Tasmania survived until humans arrived 800 years ago. In 1999 a rigorously tested radiocarbon dating showed that the last occurrence of ground sloths in Cuba was 6250 years ago, around the time that people first arrived there. Ground sloths went extinct on the continent 13,000 years ago. Of course, there was no large extinction event in Africa, where the megafauna and humans had coevolved. In 1839 Charles Darwin wrote ‘It is impossible to reflect on the state of the American continent without astonishment. Formerly it must have swarmed with great monsters; now we find mere pygmies compared with the antecedent races. “ On pages 3 & 4 are images of 28 species of large mammals that went extinct at the end of the last glacial advance; 64 such species are listed below. Alfred Russel Wallace observed that on a global scale, ‘We live in a zoologically impoverished world, from which all the hugest and fiercest and strangest forms have recently disappeared." compiled by Dana Visalli/[email protected]/www.methownaturalist.com Pleistocene Mammal Extinctions in North America Common Name Scientific Name Family Last Appearance (years ago) Xenarthra (anteaters, sloths and armadillos) Beautiful armadillo Dasypus bellus Panamerican ground sloth Eremotherium laurillardi Rusconi's ground sloth Eremotherium rusconi Ground sloth Glossotherium robustum Simpson's glyptodont Glyptotherium floridanum Northern pampathere Holmesina major (3+ species) Jefferson's ground sloth Megalonyx jeffersonii Florida ground sloth Megalonyx leptostomus Shasta ground sloth Nothrotheriops shastensis Harlan’s Ground sloth Paramylodon harlani Dasypodidae Megatheriidae Megatheriidae Mylodontidae Glyptodontidae Pampatheriidae Megalonychidae Megalonychidae Megatheriidae Mylodontidae 11,000 11,000 39,000 9000 23,000 11,000 11,500 11,000 11,500 11,000 Carnivora Giant short-faced bear Short-faced skunk Dire wolf Dhole Scimitar cat American cheetah1 American cheetah2 American lion Sabertooth Cat Florida cave bear Arctodus simus Brachyprotoma obtusata Canis dirus Cuon alpinus* Homotherium serum Miracinonyx inexpectatus Miracinonyx trumani Panthera (leo) atrox Smilodon fatalis Tremarctos floridanus Ursidae Mustelidae Canidae Canidae Felidae Felidae Felidae Felidae Felidae Ursidae 11,000 13.700 9000 12,000 10,000 11,000 15,000 11,000 11,000 23,000 Rodentia Giant beaver Giant beaver Holmes's capybara Pinckney's capybara Castoroides leiseyorum Castoroides ohioensis Hydrochoeris holmesi Neochoerus pinckneyi Castoridae Castoridae Hydrochoeridae Hydrochoeridae 11,000 11,000 12,000 ~13,000 Lagomorpha Aztlan rabbit Aztlanolagus agilis Leporidae >31,000 Perissodactyla Mexican horse Yukon horse Scott’s horse Hagerman horse California tapir Cope’s tapir California tapir Vero tapir Equus conversidens Equus lambei Equus scotti Equus simplicidens Tapirus californicus Tapirus copei Tapirus merriami Tapirus veroensis Equidae Equidae Equidae` Equidae Tapiridae Tapiridae Tapiridae Tapiridae 11,000 11,000 11,000 10,000 11,000 11,000 11,000 12,000 Artiodactyla Long-horned bison Steppe bison Harlan’s musk-ox Yesterday’s (Western) camel Bison latifrons Bison priscus (antiquus) Bootherium bombifrons Camelops hesternus Bovidae Bovidae Bovidae Camelidae 20,000 8000 11,000 10,500 Diminutive pronghorn Stag moose Shrub ox Large-headed llama Long-nosed peccary Mountain deer Harrington’s mountain goat Stout-legged llama Flat-headed peccary Pronghorn Saiga Shuler’s pronghorn Capromeryx minor (3 species) Antilocapridae Cervalces scotti Cervidae Euceratherium collinum Bovidae Hemiauchenia macrocephala Camelidae Mylohyus (5 species) Tayiassuidae Odocoileus lucasi (was Navahoceros) Cervidae Oreamnos harringtoni Caprinidae Palaeolama mirifica Camelidae Platygonus (9 species) Tayassuidae Stockoceros onusrosagris Antilocapridae Saiga tartarica* Bovidae Tetrameryx schuleri Antilocapridae Proboscidea Gomphothere American mastodon Columbian mammoth ~64 species listed Cuvieronius hyodon Mammut americanum Mammuthus columbi Gomphotheriidae Mammutidae Elephantidae 12,500 10,500 10,500 Amplibuteo woodwardi Breagyps sp Buteogallus daggetti Chendytes lawi Cicona matha Meleagris californica Neogyps errans Spizaetus grinnelli Teratornis merriami Teratornis wooodburnensis Accipitridae Ca5thartidae Accipitridae Anatidae Ciconiidae Meleagrididae Accipitridae Accipitridae Teratornithidae Teratornithidae 12,000 13,000 13,000 2500 ~13,000 10,000 ~13,000 ~13,000 10,000 11,000 Aves- Birds Woodward’s eagle American condor Dagett’s walking eagle Sea Duck La Brea stork California turkey Errant eagle Floridan hawk eagle Merriam’s Teratorn Teratorn 12,000 11,500 11,500 12,000 12,000 13,000 12,000 11,000 11,000 11,000 12,000 23,000 *The two starred species are extinct in North America but still exist elsewhere http://en.wikipedia.org/wiki/List_of_North_American_animals_extinct_in_the_Holocene (names many species, not all) http://en.wikipedia.org/wiki/Timeline_of_extinctions This timeline runs from 12,000 years ago to about the year 2000. Extinct North American Pleistocene Mammals Beautiful Armadillo Dasypus bellus Panamerican Ground Sloth Eremotherium laurillardi Ground Sloth Glossotherium robustum Panamerican Ground Sloth Eremotherium laurillardi Jefferson’s Ground Sloth Megalonyx jeffersonii Shasta Ground Sloth Nothrotheriops shastensis Giant Short-faced Bear Arctodus simus Dire Wolf Canis dirus Scimitar Cat Homotherium serum American Lion Panthera atrox Sabertooth Cat Smilidon fatalis Mexican Horse Equus conversidens Yukon Horse Equus lambei California Tapir Tapirus californicus Vero Tapir Tapirus veroensis Harlan’s Musk-ox Bootherium bombifrons Yesterday’s Camel Camelops hesternum Short-legged Llama Palaeolama mirifica Shrub Ox Euceratherium collinum Large-headed Llama Hemiauchenia macrocephala Stag Moose Cervales scotti Long-horned Bison Bison latifrons Gomphothere Cuvieronius hyodon American Mastodon Mammut americanum Columbian Mammoth Mammuthus comumbi Pygmy Mammoth Mammuthus exilis Woolly Mammoth Mammuthus prmigenius compiled by Dana Visalli/[email protected]/www.methownaturalist.com Mass extinctions of large mammals (and large birds) occurred on different continents and islands soon after humans arrived in those places. Graphic from The Diversity of Life by E.O. Wilson.
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