http://www.abc.net.au/beasts/evidence/prog2/page5.htmhttp://www.abc.net.au/beasts/http://www.kenozoicum.nl/database/andrewsarchus.htmlhttp://scienceblogs.com/tetrapodzoology/2009/08/mesonychians_part_i.phphttp://scienceblogs.com/tetrapodzoology/2009/08/mesonychians_part_ii.php

http://ombdinotopia.proboards.com/index.cgi?board=dinotopia&action=display&thread=360&page=8

evodisku. Hyenas

Aepycamelus.jpg http://ombdinotopia.proboards.com/index.cgi?board=dinotopia&action=display&thread=360&page=10

Andrewsarchus http://news.bbc.co.uk/2/hi/science/nature/6503045.stm

Andrewsarchus was the largest carnivorous land mammal to stalk the Earth. It lived about 32-60 million years ago. (Image: BBC Walking With Beasts)

http://nl.wikipedia.org/wiki/Mesonychiden

De Andrewsarchus is waarschijnlijk het grootste vleesetende landzoogdier dat ooit bestaan heeft. Verder weten we vrijwel niets van dit uitgestorven dier. Het enige overblijfsel is een fossiele schedel, die nu in het American Museum of Natural History in New York ligt. 

De schedel is in 1923 door paleontoloog (deskundige op het gebied van uitgestorven leven) Roy Chapman Andrews in de Gobiwoestijn in Mongolië gevonden. Het dier werd Andrewsarchus mongoliensis genoemd, letterlijk Andrews beest uit Mongolië. De 83 cm lange schedel stamt uit het Eoceen, een tijdperk dat duurde van 55 tot 35 miljoen jaar geleden. Aan het gebit is te zien dat de Andrewsarchus een vleeseter was. Het blijft echter een mysterie wat voor diersoort de Andrewsarchus is. Wanneer we meer fossielen van de Andrewsarchus of van verwante soorten vinden, kan het raadsel misschien opgelost worden. 

Andrewsarchus is bekend geworden door de BBC-serie Walking with Beasts. Omdat alleen de schedel bekend is, blijft het gissen naar de rest. Schedel en gebit lijken op die van de beter bekende Mesonychiden. Daarom is in deze reconstructie gekozen voor een lichaam dat gebaseerd

is op fossielen van deze uitgestorven dieren. In vergelijking met de reconstructie uit Walking with Beasts zitten de ogen lager, zijn de oren kleiner, heeft de vacht een andere kleur en is de staart een stuk korter. Omdat hij zo groot was en door de vorm van zijn gebit denken we dat Andrewsarchus een aaseter was. Aaseters jagen niet en hebben geen grote oren nodig om hun voedsel op te sporen.

Wolf? Andrewsarchus lijkt op een reusachtige wolf. Maar de schedel en het gebit vertonen weinig overeenkomsten. Omdat ze beide min of meer dezelfde leefwijze hebben lijken ze veel op elkaar. Uit onze tijd kennen we dit verschijnsel, parallelle evolutie genoemd, van de wolf, Canis lupus, en de buidelwolf, Thylacinus cynocephalus, die in Tasmanië, Australië en Nieuw-Guinea leefde.

brontotherium. Image taken from the site http://geologix.free.fr/Paleontologie/ceno.htmNo copyright was pointed at this site

Brontotherium ('thunder beast') is an extinct genus of mammal.

The 2.50 m (8 ft 4 in) tall creature resembled a rhinoceros, possessing a forked (in a Y, or slingshot shape), horn-like protrusion on its nose, with blunt ends. Many Brontotherium remains have been found in South Dakota and Nebraska. In the past, specimens exposed by severe rainstorms were found by Native Americans of the Sioux tribe. The Sioux believed these creatures produced thunderstorms when running over the clouds, and called them 'thunder horses'. Many of the skeletons found by the Sioux belonged to herds which were killed by volcanic eruptions of the Rocky Mountains, which were volcanically active at the time.

Brontotherium's dorsal vertebrae above the shoulders had extra long spines to support the huge neck muscles needed to carry the heavy skull. Possibly, Brontotherium had fleshy lips and a longe tongue, perfect for carefully selecting preferred food (soft stems and leaves).

According to Mihlbachler et al. 2004, the species within genus Brontotherium were merged with the genus Megacerops, though not all authorities agree on this.

© 2007 Answers Corporation

creodonts 2.JPG

Chasmoporthetes

Hyanodon.JPG http://www.ansp.org/museum/leidy/paleo/hyaenodon.phphttp://fingerlakesfossilfarm.org/mammal_fossils.htm

hyaenodon.jpg Creodonta

Creodonts are an extinct group of carnivorous mammals that were long thought to be the ancestors of modern Carnivora. This is no longer thought to be the case. Creodonts were the dominant group of carnivorous mammals in the early Tertiary and were quite diverse. They ranged from very large, wolf-like animals as Hyaenodon to small mongoose-like forms such as Prototomus vulpeculus.

Creodonts lived in North America, Asia, Europe, and Africa.

Extante hyanidae

Doedicurus The giant glyptodonts rival their relatives, the giant ground sloths, for the title of 'most impressive beast of South America'. Although they are related to modern armadillos (as well as the sloths and anteaters), they grew to the size of a small car.

Like the ground sloth, glyptodonts became extinct only thousands of years ago, so their remains are still very well preserved. Their great carapaces were probably originally like those of modern armadillos rather than tortoises, made up of many tiny plates called scutes. The carapace would have been more flexible around the edges, where the scutes were laid down in regular lines, and not fused together. Doedicurus' tail is its most impressive feature. It is solid bone, and at the end are round scars that show where the horny spikes were positioned.

elasmotherium1.gif http://ombdinotopia.proboards.com/index.cgi?board=dinotopia&action=display&thread=360&page=7

Eremotherium laurillardi

In the Late Pleistocene Epoch of Florida, there existed a diverse mammalian fauna which included some of the largest mammals to ever exist on our planet. Among these giants were huge mastodons and woolly mammoths, semi-aquatic gomphothere elephants, bison with 8 foot horn spreads, huge camels, giant armadillos the size of Volkswagen Bugs, and huge ground sloths; the largest of which was Eremotherium.

Eremotherium is the largest sloth to have ever existed and is believed to have migrated from South American to North America during the Middle Pleistocene, approximately 2.2 million years ago, over the then newly-formed Panamanian land bridge. It was the largest mammal in the western hemisphere aside from the giant Woolly Mammoth and weighed approximately 5 tons at full maturity and stood up to 15 feet tall. The Eremotheres possessed huge foot-long claws on their hands whichmay have looked fearsome and deadly but were likely only used to denude tree limbs of their tender shoots and leaves. A powerful but stubby tail functioned as a third leg to form a tripod with the legs and massive hips, providing great stabilitywhen the animal was leaning back and stretching upward to reach the highest tree branches in order to consume the most succulent foliage. The massive arms and wide hips would allow this sloth to pull down huge branches and even whole treesif desired, and this likely led to total devastation of the forest in areas where these giant sloths were feeding. Eremotherium was a nearly perfectly designed tree destroyer and thrived in the lush tropical rainforest environments of the Florida Pleistocene. It had no natural enemies because of its size; and even the huge bears and saber-toothed tigers that coexisted with this sloth could not challenge an adult. It is possible the juveniles would have been vulnerable to attackfrom the largest and most powerful carnivores, but it is also quite likely these sloths possessed a strong maternal instinct that would've made a mother sloth a very aggressive and dangerous opponent in the event of an attack on its offspring.

The DiscoveryOver 180,000 years ago, near where the Daytona International Speedway is today, a herd of giant sloths were peacefully feeding on lush vegetation amid a grove of trees, when a catastrophic flash

flood swept them into an estuary and out to sea where they drowned. Their carcasses soon sank and collected in a channel-lag, an area where the current suddenly decreases on the edges of an underwater channel. Sharks, crabs, and other organisms scavenged on some of the carcasses, but luckily silt and sand quickly covered the sloths and preserved them largely intact up until modern times. Over tens of thousands of years, the sloth graveyard was covered by 30 feet of silt, sand, shells, corals and other marine remains.

In October of 1975, what was once an undersea channel was now a dry land borrow pit quarry for road bed material. Amateur paleontologist and full-time TV repairman Don Serbousek and his friend, Roger Alexon, were out hunting fossils in the borrow pit when they made the discovery of a lifetime.In the quarry wall they saw dozens of chocolate-brown fossil bones exposed in a peaty clay layer 12 feet below the ground level.In this bone bed, they found the remains of the giant ground sloth, Eremotherium, and in great quantity. Most of the sloth bones they collected belonged to just one individual, but there were isolated bones of many different individuals found indicating that the site could be prolific.Realizing the scientific importance of his find, Serbousek contacted world-renowned sloth expert Dr. Gordon Edmund, then Curator of Vertebrate Paleontology at the Royal Ontario Museum in Toronto.

Dr. Edmund proclaimed upon visiting the site and seeing the nearly complete skeleton, "From my research, I'd say this is by far the best Eremotherium, or giant sloth, skeleton discovered in North America."

With Dr. Edmund's imprimatur, plans were made for a complete and thorough scientific excavation of the site.The Volusia County government authorized public funds to expose the bone layer by stripping off the top layers of the shell beds, draining the groundwater from the pit, and using high pressure hoses to help clear matrix from around the bones.Over the next two years a team of scientists and volunteers, along with Serbousek and his friends, toiled long days in the pit using the water hoses to extract the bones while other volunteers worked to clean and conserve the bones in a preparation lab. Tens of thousands of man hours were invested in collecting and preserving the incredible giant sloth fossils found in the "Daytona Bone Bed", as it was named by Dr. Edmund in the scientific paper he published about the site. After the excavation work was completed, over 1,300 giant sloth bones had been collected from 11 different individuals in the herd; however, there were only two complete skeletons found. All of the specimens were initially taken to the Royal Ontario Museum for study and publication, with one skeleton to be mounted and returned to the Museum of Arts and Sciences in Daytona. The other unmounted skeleton was given to Don Serbousek in grateful appreciation for him selflessly bringing the most important giant sloth site ever found to the attention of science, and for his tireless efforts managing and excavating the site over the course of two years. The rest of the 1,300+ bones found during the dig were accessioned into the permanent collection of the Royal Ontario Museum where they reside to this day.

The Present SpecimenThe complete mounted skeleton here is the Serbousek specimen, and it is the sister specimen to the skeleton currently on display at the Museum of Arts and Sciences in Daytona Beach, Florida. The Serbousek sloth bones were initially prepared by technicians at the Royal Ontario Museum, and some missing elements were provided by them in the form of casts or real bones from other individuals so that Mr. Serbousek would have a100% complete skeleton to mount. Unfortunately, making the armature and mounting such a huge skeleton is a very expensive and time-consuming process that Mr. Serbousek was never able to accomplish it in his lifetime.Over 80% of the original bones are present in this specimen, with only the following major elements being casts: pelvis, sternum, and sternal ribs. Minor cast elements include one thoracic vertebra, 5 ribs, several tail vertebrae and chevrons, and some foot and hand bones.

The skull is superb and original with all original teeth but has restored zygomatic arches and minor crack repair. The skeleton mount was completed in November, 2010, only three months after Mr. Serbousek's death at the age of 83, and is now ready to be displayed proudly in any museum or private collection in the world. As mounted, this skeleton measures 15 feet in length from head to tail yet stands 11 feet tall from the floor. It measures 5 feet wide across the hips, with the massive skull measuring 28 inches long by 14 inches wide by 15 inches tall. The natural color of the bone is a gorgeous chocolate brown, making for a truly beautiful and exquisite mount. There are only 3 known complete skeletons of these giant sloths mounted in museums around the world; one in the MOAS at Daytona Beach, Florida; one in the Smithsonian Institution, Washington, D.C.; and one in the British Museum of Natural History, London.

Giant ground sloths

MegatheriumOld.gif http://ombdinotopia.proboards.com/index.cgi?board=dinotopia&action=display&thread=360&page=8

Megather iumMegatherium était un paresseux terrestre préhistorique de la taille d'un éléphant. Il ne grimpait pas aux arbres mais amenait les branches à sa bouche à l'aide de ses grosses griffes courbes. Il les mâchait ensuite avec ses dents en forme de cheville.Les ParesseuxLes grands paresseux terrestres étaient parmi les plus gros mammifères d'Amérique. Les paresseux actuels descendent rarement au sol.

La classification des paresseux a fait l'objet de plusieurs modifications.

A l'origine, le paresseux était classé dans l'ordre des Edentés. Cette classification n'était pas logique car cet animal possède 18 dents rudimentaires qui sont dépourvues d’émail et de réelles racines.

Jusqu'à récemment, le paresseux avait été reclassé dans l’ordre des Xénarthres. Cet ordre regroupait également les fourmiliers et les tatous. Cet ordre est devenu un super-ordre divisé en deux ordres.

Aujourd'hui, les six espèces de paresseux sont classées dans l'ordre des Pilosa.

Les paresseux vivent en Amérique du Sud et en Amérique centrale. © dinosoria.com

Parmi les paresseux préhistoriques , les plus connus sont les plus gros comme Nothrotheriops shastensis qui mesurait 1,25 m à l'épaule. Il vivait en Amérique du Nord et centrale. Le plus gigantesque est bien sûrMegatherium americanum qui atteignait 2,15 m à l'épaule.

Les derniers paresseux terrestres ont disparu à la fin de la dernière période glaciaire, il y a

environ 10 000 ans.

Fossile d'un paresseux préhistorique. By Ajschu

Des morceaux de fourrure et d'excréments ont été retrouvés dans des grottes. Les restes végétaux trouvés dans leurs excréments indiquent qu'ils se nourrissaient de plantes de régions arides ou désertiques mais aussi des régions tempérées.

Megatherium americanumDes squelettes complets et des restes momifiés ont été conservés avec la peau, les tendons et la fourrure.

Megatherium americanum vivait en Amérique du Sud (4 - 0,011 Ma) et en Amérique du Nord (1,8 - 0,011 Ma) jusqu'à une époque assez récente.

A cette époque, il y avait de nombreux paresseux terrestres. Megatherium et Eremotherium font partie des plus imposants. On estime leur taille à 6 m de long pour un poids d'environ 3 tonnes.

Squelette de Megatherium. By Seriykotik 1970

Megatherium possédait une queue épaisse qui lui servait de point d'appui pour pouvoir soulever son corps vers les branchages. Il possédait 5 doigts terminés par de grosses griffes. Il disposait d'un système de defense naturelle. Sous sa peau, un réseau de petits os agissait comme une cotte de maille. Le Megatherium adulte était quasiment indestructible.

Megatherium. By Garrettc

Son squelette massif et son bassin particulièrement large semblent indiquer que l'animal se déplaçait lentement et était capable de se dresser ou de s'accroupir, libérant ses bras pour attraper la végétation.

Glossotherium était également un paresseux terrestre mais de taille moyenne. Il vivait en Amérique du Sud et en Amérique du Nord au Miocène, Pliocène et Pléistocène. Il s'est éteint il y a environ 12 000 ans.

Glossotherium. By akseabird

Megatherium fait partie du super-ordre des Xenarthres "articulations étranges". Ce groupe est constitué de mammifères placentaires américains. De nos jours, les représentants de ce groupe sont les paresseux, les fourmiliers et les tatous.

Classification: Mammalia. Xenarthra. Pilosa. Megatheriidae. Megatherium

Megatherium

Mesonyx. Mesonyx, een primitief roofdier van de familie Mesonychidae, leefde van het midden-Paleoceen tot het einde van het Eoceen (Scott, 1988)http://scienceblogs.com/tetrapodzoology/2009/08/mesonychians_part_iv.php

Moropus (meaning "slow foot") is an extinct mammal, belonging to a group called chalicotheres, which were perissodactyl ("odd-toed") mammals that include the modern horse, rhino, and tapir. Moropus lived mainly during the Miocene epoch.

Like other chalicotheres, they differed from their modern relatives in having large claws, rather than hooves, on the front feet; these claws may have been used for defense or digging for food. Moropus stood about eight feet tall at the shoulder.

Fossils of Moropus have been found in North America.

© 2007 Answers Corporation

Smilodon Smilodon is the famous 'sabre-toothed cat'. Many people call it a 'sabre-toothed tiger', but of all the sabre-toothed animals that ever lived, not one was a tiger.

The sabres are actually quite delicate - any contact with bone and they would shatter. They could only be used in the soft parts of the victim, and the cat needed to use strong front legs to hold it still.

Out of the huge numbers of bones from California, many of them show serious, healed injuries suggesting that the animals lived in groups, enabling injured animals to feed from group kills until their wounds healed.

Smilodon Sabeltandtijger Bbc serie uit 2001, Smilodon reconstructie door Nigel boothZie ook /Katten

paraceratherium.http://www.bbc.co.uk/nature/life/Paraceratherium

Mammals family tree [1.6MB]

THE FULL FAMILY TREE

De volledige stamboom der zoogdieren http://news.bbc.co.uk/2/shared/bsp/hi/pdfs/28_03_07_mammalstimeline_pdf.pdf

Gebruik de " zoom"functie op de rand van de cirkel ( tot x 3200) om de details te zien van de afstammingslijnen van diverse zoogdieren

De meeste computers zullen dit document automatisch openen Maar u hebt wel "Adobe Reader" nodig

Dowload hier indien nodig -->Adobe reader http://get.adobe.com/nl/reader/