Cambaytherium thewissi: a Basal Perissodactyl From Ypresian Eocene Paleogene India

Working at the edge of a coal mine in India, a team of Johns Hopkins researchers and colleagues have filled in a major gap in science's understanding of the evolution of a group of animals that includes horses and rhinos. That group likely originated on the subcontinent when it was still an island headed swiftly for collision with Asia, the researchers report Nov. 20 in the online journal Nature Communications.

Modern horses, rhinos and tapirs belong to a biological group, or order, called Perissodactyla. Also known as "odd-toed ungulates," animals in the order have, as their name implies, an uneven number of toes on their hind feet and a distinctive digestive system. Though paleontologists had found remains of Perissodactyla from as far back as the beginnings of the Eocene epoch, about 56 million years ago, their earlier evolution remained a mystery, says Ken Rose, Ph.D., a professor of functional anatomy and evolution at the Johns Hopkins University School of Medicine.

Rose and his research team have for years been excavating mammal fossils in the Bighorn Basin of Wyoming, but in 2001 he and Indian colleagues began exploring Eocene sediments in Western India because it had been proposed that perissodactyls and some other mammal groups might have originated there. In an open-pit coal mine northeast of Mumbai, they uncovered a rich vein of ancient bones. Rose says he and his collaborators obtained funding from the National Geographic Society to send a research team to the mine site at Gujarat in the far Western part of India for two weeks at a time once every year or two over the last decade.

The mine yielded what Rose says was a treasure trove of teeth and bones for the researchers to comb through back in their home laboratories. Of these, more than 200 fossils turned out to belong to an animal dubbed Cambaytherium thewissi, about which little had been known. The researchers dated the fossils to about 54.5 million years old, making them slightly younger than the oldest known Perissodactyla remains, but, Rose says, it provides a window into what a common ancestor of all Perissodactyla would have looked like. "Many of Cambaytherium's features, like the teeth, the number of sacral vertebrae, and the bones of the hands and feet, are intermediate between Perissodactyla and more primitive animals," Rose says. "This is the closest thing we've found to a common ancestor of the Perissodactyla order."

Cambaytherium and other finds from the Gujarat coal mine also provide tantalizing clues about India's separation from Madagascar, lonely migration, and eventual collision with the continent of Asia as the Earth's plates shifted, Rose says. In 1990, two researchers, David Krause and Mary Maas of Stony Brook University, published a paper suggesting that several groups of mammals that appear at the beginning of the Eocene, including primates and odd- and even-toed ungulates, might have evolved in India while it was isolated. Cambaytherium is the first concrete evidence to support that idea, Rose says. But, he adds, "It's not a simple story."

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Oldest Known Mammals From Antarctica are Eocene Paleogene Ungulates

The oldest mammals from Antarctica, early Eocene of the La Meseta Formation, Seymour Island

Authors:

Gelfo et al

Abstract:

New fossil mammals found at the base of Acantilados II Allomember of the La Meseta Formation, from the early Eocene (Ypresian) of Seymour Island, represent the oldest evidence of this group in Antarctica. Two specimens are here described; the first belongs to a talonid portion of a lower right molar assigned to the sparnotheriodontid litoptern Notiolofos sp. cf. N. arquinotiensis. Sparnotheriodontid were medium- to large-sized ungulates, with a wide distribution in the Eocene of South America and Antarctica. The second specimen is an intermediate phalanx referred to an indeterminate Eutheria, probably a South American native ungulate. These Antarctic findings in sediments of 55.3 Ma query the minimum age needed for terrestrial mammals to spread from South America to Antarctica, which should have occurred before the final break-up of Gondwana. This event involves the disappearance of the land bridge formed by the Weddellian Isthmus, which connected West Antarctica and southern South America from the Late Cretaceous until sometime in the earliest Palaeogene.

Gastornis: A Giant Flightless Bird Found in Ypresian Eocene Paleogene Europe (as well as NorAm)

The birds (Aves) from the Early Eocene of La Borie, southern France

Authors:

Bourdon et al

Abstract:

The Early Eocene locality of La Borie is located in the village of Saint-Papoul, in southern France. These Eocene fluvio-lacustrine clay deposits have yielded numerous vertebrate remains. Mammalian taxa found in the fossiliferous levels indicate an age near the reference level MP 8–9, which corresponds to the middle Ypresian, Lower Eocene. Here we provide a detailed description of the avian remains that were preliminarily reported in a recent study of the vertebrate fauna from La Borie. A maxilla, a quadrate, cervical vertebrae, a femur and two tibiotarsi are assigned to the giant ground bird Gastornis parisiensis Hébert, 1855 (Gastornithidae). These new avian remains add to the fossil record of Gastornis, which is known from the Upper Paleocene to Middle Eocene of Europe, Early Eocene of Asia, and Early Eocene of North America. Gastornis parisiensis differs from the North American Gastornis giganteus (Cope, 1876) in several features, including the more ventral position of the external nares and the slender orbital process of quadrate. Two tibiotarsi and one tarsometatarsus are assigned to a new genus and species of Geranoididae, Galligeranoides boriensis gen. nov, sp. nov. So far, this family was known only from the Early and Middle Eocene of North America. The fossils from La Borie constitute the first record of the Geranoididae in Europe. We show that Gastornis coexisted with the Geranoididae in the Lower Eocene of both Europe (La Borie) and North America (Willwood formation). The presence of Geranoididae and the large flightless bird Gastornis on either side of the present-day North Atlantic provides further evidence that a high-latitude land connection existed between Europe and North America in the Early Eocene.

A new Ypresian Eocene Paleogene Lagerstätte From Italy

A new Fossil-Lagerstätte from the Lower Eocene of Lessini Mountains (northern Italy): A multidisciplinary approach

Authors:

Giusberti et al

Abstract:

Hemipelagic dark limestones within calciturbiditic deposits at Monte Solane in the western Lessini Mountains of northern Italy yield a fish fauna dominated by stomiiforms. A minor component of the fossil assemblage is represented by a macroalgal non-calcareous flora associated with rarer terrestrial components including few angiosperm leaves and seeds. Micropaleontological (foraminifera, dinoflagellate cysts), sedimentological and geochemical proxies (TEX86) indicate a deposition of the fossil-bearing bed in a hypoxic to possibly anoxic, warm, restricted basin. High-precision dating based on rich foraminiferal and calcareous nannoplankton content allows ascribing the site to the upper part of the Ypresian (Lower Eocene). The site is slightly older than the Ypresian worldwide-famous shallow-water Bolca Konservat-Lagerstätte located in the same region. Convergent paleoenvironmental clues based on both microfossils and ichthyofauna indicate that the sediments were deposited in the upper bathyal zone, probably between 300 and 600 m. Solane is therefore one of the rare and precious Eocene Lagerstätte to have fossilized in a deep marine setting. The site contains the oldest Cenozoic record of an ichthyofauna dominated by meso-bathypelagic taxa.

Culinary Paleontology: World's Oldest Tomatillo Fossil Found in Ypresian Eocene Paleogene Argentina

A fossilized tomatillo, still in its papery shell, is the earliest fruit from the tomato family ever found in South America, researchers reported Oct. 30 at the Geological Society of America's annual meeting in Denver.

The 52.2-million-year-old tomatillo was discovered at the fossil-rich Laguna del Hunco, Argentina, where ancient lakebeds interlayer with volcanic ashes, providing paleontologists with precisely dated discoveries. (Minerals in the ash pin down the rock ages.)

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Archicebus achilles: Oldest Tarsier-like (tarsiiforme) Primate, Oldest with Skeleton

An international team of paleontologists that includes Northern Illinois University anthropologist Dan Gebo is announcing the discovery of a nearly complete, articulated skeleton of a new tiny, tree-dwelling primate dating back 55 million years.

The Eocene Epoch fossil was recovered from Hubei Province in central China.

"This is the oldest primate skeleton of this quality and completeness ever discovered and one of the most primitive primate fossils ever documented," Gebo said. "The origin of primates sets the first milestone for all primate lineages, including that of humanity.

"Although scientists have found primate teeth, jaws, occasionally skulls or a few limb bones from this time period, none of this evidence is as complete as this new skeleton from China," Gebo added. "With completeness comes more information and better evidence for the adaptive and evolutionary themes concerning primate evolution. It takes guessing out of the game."

The research team, led by Xijun Ni of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) at the Chinese Academy of Sciences in Beijing, describes the fossil in the June 6 edition of the prestigious science journal, Nature.

paper link.  

Canadian Eocene Mountain Insect Biodiversity Parallels Modern Tropics

Simon Fraser University evolutionary biologists Bruce Archibald and Rolf Mathewes, and Brandon University biologist David Greenwood, have discovered that modern tropical mountains' diversity patterns extended up into Canada about 50 million years ago.

Their findings confirm an influential theory about change in modern species diversity across mountains, and provide evidence that global biodiversity was greater in ancient times than now.

The scientific journal Palaeogeography, Palaeoclimatology, Palaeoecology has published their research.

About 45 years ago, an evolutionary biologist at the University of Pennsylvania theorized that change in species from site to site across mountain ranges in the tropics should be greater than in temperate latitudes.

Daniel Janzen reasoned that the great difference between summer and winter in temperate latitudes (high seasonality) offers a wide window to migrate across mountainous regions. The small difference in the tropics (low seasonality) allows a very narrow opportunity, annually. Consequently, communities across tropical mountains should have fewer of the same species. Many studies examining modern communities support this theory.

Archibald, Mathewes and Greenwood realized that fossil beds across a thousand kilometres of the ancient mountains of British Columbia and Washington provided a unique lens through which to deepen evaluation of this theory. Fifty million years ago, when these fossil beds were laid down, the world had low seasonality outside of the tropics, right to the poles. Because of this, if Janzen's theory is right, the pattern of biodiversity that he described in modern tropical mountains should have extended well into higher latitudes.

"We found that insect species changed greatly across British Columbia's and Washington State's ancient mountain ranges, like in the modern tropics," Archibald says, "exactly as Janzen's seasonality hypothesis predicted.

This implies that it's the particular seasonality now found in the modern tropics, not where that climate is situated globally, that affects this biodiversity pattern." He adds: "Sometimes it helps to look to the ancient past to better understand how things work today." The findings also bolster the idea that ancient Earth was a much more diverse world than now with many more species.

Eocene Lizard Fossil Skin Put Through Synchotron...And Teeth Found!

Synchrotron-based imaging techniques of a 50 million-year-old lizard skin have identified the presence of teeth which are invisible to visible light, demonstrating for the first time that this fossil animal was more than just a skin moult.

Researchers used Synchrotron Rapid Screening X-ray Fluorescence at the Stanford Synchrotron Radiation Lightsource in California to map the chemical make up of a rare fossil lizard skin - powerful x-rays enabled the team to map the presence of phosphorus from teeth in this ancient reptile.

The relative position of the phosphorous in the skin fossil helped the scientists identify the type of lizard. They believe that the more elongated snout in conjunction with the general jaw shape bears a strong resemblance to a shinisaurid lizard (Bahndwivici ammoskius). The presence of phosphorous also demonstrates for the first time that the fossil skin is more than just a moult, as no lizards can shed their teeth along with their skin!

Dr. Phil Manning from the Palaeontology Research group at the University of Manchester said, "Finding the presence of teeth changes almost everything we thought we knew about this fossil. We can identify the type of lizard for the first time, based upon the geometry of the teeth. Our findings also raise some fascinating questions about what happened to the animal after its death. What wiped out its bones but preserved the skin and the ghost of its teeth?

"The technique permits us to tease-out chemical information from fossils, information that you simply cannot see with the naked eye. Such chemical maps can help us see 'ghosts' of original biological structures that only remain in very dilute concentrations in the fossil."

When the Tropics are the Poles: Baobabs in Antarctica During the Eocene

Given the predicted rise in global temperatures in the coming decades, climate scientists are particularly interested in warm periods that occurred in the geological past. Knowledge of past episodes of global warmth can be used to better understand the relationship between climate change, variations in atmospheric carbon dioxide and the reaction of Earth's biosphere. An international team led by scientists from the Goethe University and the Biodiversity and Climate Research Centre in Frankfurt, Germany, has discovered an intense warming phase around 52 million years ago in drill cores obtained from the seafloor near Antarctica — a region that is especially important in climate research. The study published in the journal Nature shows that tropical vegetation, including palms and relatives of today's tropical Baobab trees, was growing on the coast of Antarctica 52 million years ago. These results highlight the extreme contrast between modern and past climatic conditions on Antarctica and the extent of global warmth during periods of elevated atmospheric carbon dioxide levels.

Around 52 million years ago, the concentration of the greenhouse gas carbon dioxide (CO2) in the atmosphere was more than twice as high as today. "If the current CO2 emissions continue unabated due to the burning of fossil fuels, CO2 concentrations in the atmosphere, as they existed in the distant past, are likely to be achieved within a few hundred years", explains Prof. Jörg Pross, a paleoclimatologist at the Goethe University and member of the Biodiversity and Climate Research Centre (BiK-F) in Frankfurt, Germany. "By studying naturally occurring climate warming periods in the geological past, our knowledge of the mechanisms and processes in the climate system increases. This contributes enormously to improving our understanding of current human-induced global warming."

Computer models indicate that future climate warming will be particularly pronounced in high-latitude regions, i.e., near the poles. Until now, however, it has been unclear how Antarctic terrestrial ecosystems responded in the geological past to a greenhouse climate with high atmospheric CO2 concentrations.

The scientists working with Prof. Pross analysed rock samples from drill cores on the seabed, which were obtained off the coast of Wilkes Land, Antarctica, as part of the Integrated Ocean Drilling Program (IODP). The rock samples are between 53 and 46 million years old and contain fossil pollen and spores that are known to originate from the Antarctic coastal region. The researchers were thus able to reconstruct the local vegetation on Antarctica and, accordingly, interpret the presence of tropical and subtropical rainforests covering the coastal region 52 million years ago.

In an area where the Antarctic ice sheet borders the Southern Ocean today, frost-sensitive and warmth-loving plants such as palms and the ancestors of today's baobab trees flourished 52 million years ago. The scientists' evaluations show that the winter temperatures on the Wilkes Land coast of Antarctica were warmer than 10 degrees Celsius at that time, despite three months of polar night. The continental interior, however, was noticeably cooler, with the climate supporting the growth of temperate rainforests characterized by southern beech and Araucaria trees of the type common in New Zealand today. Additional evidence of extremely mild temperatures was provided by analysis of organic compounds that were produced by soil bacteria populating the soils along the Antarctic coast.

These new findings from Antarctica also imply that the temperature difference between the low latitudes and high southern latitudes during the greenhouse phase 52 million years ago was significantly smaller than previously thought. "The CO2 content of the atmosphere as assumed for that time interval is not enough on its own to explain the almost tropical conditions in the Antarctic", says Pross. "Another important factor was the transfer of heat via warm ocean currents that reached Antarctica." When the warm ocean current collapsed and the Antarctic coast came under the influence of cooler ocean currents, the tropical rainforests including palms and Baobab relatives also disappeared.

PR link.  I will link to the Nature paper when I get back.  I'm interested in reading it.