Camelidae Early camels, Poebrotherium
The discovery of the early camel Poebrotherium in the White River Badlands was initially puzzling. Few complete remains were found and nobody expected to find such a primitive camel in North America. Ultimately it was determined that camels first appeared in North America during the Unitan NALMA of the middle Eocene. Their expansion during the late Eocene coincided with a drying trend that produced the first areas of grassless savanna in North America. The limb morphology of Poebrotherium includes very elongate axial metapodials, reduced lateral metapodials and sharp ungual phalanges that suggests early camels were adapted to a cursorial existence in more open habitats. Unlike living camelids which are digitigrade and have padded feet, Poebrotherium was unguligrade and its ungual phalanges probably bore deer-like hooves. Early camels were lightly built and resembled modern llamas. Only two feet tall, perhaps 50 lb in weight and without any derived features, their eyes were located farther back in the skull when compared with those of modern camels. Their ribs were also much lighter. Poebrotherium had a split toe, a variation which would later evolve into a pad underneath these toes that is still seen in modern camels. Poebrotherium teeth are less hypsodont and more primitive than any other camelid except Poebrodon. They are small and have a hollow triangular cross-section which later evolved into more distinct dental variations adapted for plucking and grinding vegetation Teeth toward the front of the jaw are reduced in size and peg-like. The skull of Poebrotherium is approximately7 inches long and constructed of thin fragile bones. Because camel skulls are narrow and elongated, most have broken cheekbones and orbits when found and complete skulls are a rare find. Compared to other herbivores, camelids are relatively rare in the Eocene. This did not change until after the Chadronian NALMA when the remains of Poebrotherium wilsoni, the gazelle-camel, became abundant in the White River deposits of Colorado and southeastern Wyoming and although camel remains are more common in Nebraska and eastern Wyoming than in South Dakota, their remains are still rarer than those of oreodonts. Living camelids from South America, including vicuna and guanacos as well as the domesticated alpaca and llama, do not have humps and probably resemble the early camels of the White River beds. Written by Ryan C. and Alan S.
The White River Badlands
The White River Badlands has been the site of much interest for paleontologists since the mid-1800's. During these early explorations, scientists began finding fossil remains of many large mammals. These interesting discoveries soon attracted prominent paleontologists, such as the famous Dr Joseph Leidy and Prof O. C. Marsh to visit there and conduct more detailed studies. It soon became clear that this area represented a unique area of great scientific value and many museums and universities surged forward to explore these strata as well as to collect fossils from them. Numerous publications were produced discussing these discoveries. Unfortunately most of the publications were very specific to particular discoveries or sites and failed to give a broad picture of this region. It wasn't until 1920 that Cleophas O'Harra of the South Dakota School of Mines published a book on the White River Badlands, the sole purpose of which was to shed light on the area. Sadly, today there remain few useful references beyond this book, which is now over 90 years old. Times have changed. It is time to develop a website showing new fossil discoveries, clear color photographs of specimens, updated taxonomy, fossil preparation techniques and advice from active collectors and dealers who can introduce people to the and the fossils in it. Written by Ryan C.
Geography of the White River Badlands
The White River Badlands is a collection of irregularly shaped, highly eroded areas that extends from the southwestern portion of South Dakota through parts of northwestern Nebraska and eastern Wyoming into eastern Colorado. The drainage pattern of the badlands converges on the White River, hence its name. The badlands themselves are characterized by harsh rugged peaks and steep gullies, with a variety of brown and tan sedimentary layers that lie fully exposed and often capped by flat areas covered in grasses. Early exploration through this region was tough and finding food and water difficult. The area is, however, quite fertile in places and water can be found in shallow wells. Much of the badlands region is used today for grazing of cattle. To help us imagine what the Badlands are like, a quote from Prof. O'Harra, describing Sheep Mountain is appropriate. "Sheep Mountain, the cedar covered top of which overlooks all the surrounding country, presents a view that is hopelessly indescribable. In all directions everything is strange and weird to the extreme. Far away cattle or horses may be seen feeding on levels of green, and here and there distant dots indicate the abodes of happy homesteaders. Immediately about all is still. Until recently the sharp eye could occasionally detect a remnant bunch of mountain sheep, once numerous, but quickly and quietly they would steal away to the cover among the intricate recesses of the crumbling precipices. Only an occasional eagle screams out a word of curiosity or defiance as he sails majestically across the maze of projecting points and bottomless pits. Magnificent ruins of a great silent city painted in delicate shades of cream and pink and buff and green! Domes, towers and spires decorate gorgeous cathedrals and palaces and present dimensions little dreamed of by the architects of the ancients." What a magical depiction! Written by Ryan C.
Quotes from Cleophas C O'Harra
Geology and Age The White River Group, South Dakota
The oldest rocks in the White River Group are Late Eocene (late Chardonian Age) to mid-Oligocene and range from 30 to 40 million years old. In South Dakota, the Chadron Formation consists of siltstones, sandstones and sandy conglomerates which were deposited in stream channels. At the top of the Chadron Formation, these sediments shift into the Brule Formation which itself is divided into the lower Scenic Member and the Poleslide Member. The Scenic Member dates to the Middle Oligocene, 35 to 32 million years old and is composed of siltstones and sandy siltstones with some infrequent channel conglomerates. The Poleslide Member is Late Oligocene and dates from 32 to 25 million years old. These beds contain sediments which are sandier than the Scenic Member, and like beds in the early Oligocene, contain occasional ash beds. Overall the White River Group was deposited in an alluvial flood plain environment characterized by siltstones, sandstones and lenticular conglomerates. These conditions were perfect to facilitate the preservation of many unique and interesting mammal species. Written by Ryan C.
The environment of the Badlands in the Oligocene Paleoclimate of the Oligocene
The climate during the Oligocene was one that is quite different than that of today. By looking at the types of rocks found in these bed and the fossils within them, a picture of the Oligocene paleo-environment begins to reveal itself. The prominence of clays and lenticular sandstones indicates a mature river valley with a relatively flat topography, meandering rivers, punctuated by lakes and swamps. The land may have been covered by small shrub-like vegetation, with perhaps forests in parts. The landscape was populated by a great diversity of animal life, particularly. Mr. O'Harra writes a beautiful description of the life during the Oligocene: "Here the gently flowing streams push their muddy way through reedy marshlands and vigorous forests and furnish a lazy playground for countless turtles and occasional crocodiles. In favored recesses groups of rhinoceroses may be seen, some heavy of bulk and water loving, others graceful and preferring dry land. Little fleet-footed ancestral horses nibble the grass on the hillsides or trot unhindered across the muddy flats. Here and there we see a group of predaceous dogs and not infrequently do we get a glimpse of a ferocious tiger-like cat. On the higher ridges, six horned herbivores reveal their inquisitive pose, and scamper from the nearing presence of some stealthy foe. But the dominating beast is the titanothere. In great numbers we see his majestic form as he moves among his kin and crops at his leisure the coarse grasses of the lowlands. Here and there are gophers and squirrels busy with their toil and their play, and hedgehogs and moles and swine and deer and tapirs and camels, and many other creatures too strange to mention without definition. To all these animals it was home. Here they fought for food and life and supremacy. To them the sun shone, the showers came, the birds sang, the flowers bloomed, and stately trees gave convenient shade to the rollicking young of many a creature. But 'everlasting hills' have their day and rivers do not flow forever. One by one, group by group, they died, the bodies of most of them quickly feeding the surrounding elements but a chosen few, tucked away by the kindly hand of nature, remaining as unique monuments of the dawning time of the great mammalian races, are now being revealed as gently by nature again in these days of man." Such a vibrant description! Written by Ryan C. Quotes from Cleophas C O'Harra