Since its inaugural event on 22 April 1970, Earth Day has grown into an international annual celebration of the Earth and a movement to raise awareness about and support for environmental protection. This year’s theme, Restore Our Earth, emphasizes that, “As the world returns to normal, we can’t go back to business-as-usual.” As we face widespread climate change and unprecedented biodiversity declines—with one million species threatened with extinction—immediate, online access to essential literature is ever-more important, allowing scientists to conduct research more quickly and efficiently and improving our ability to respond to these crises. For fifteen years, the Biodiversity Heritage Library (BHL) has worked as a global consortium to provide this vital access, empower research, and make a real difference in our ability to improve the health of our planet for every species that calls it home.

This year, several of our global partners have selected a few titles from the BHL collection to commemorate Earth Day. From exploring Asia’s vast and unique biodiversity to inspiring conservation through a popular publication on birds, providing practical methods for conducting surveys and using the data to support conservation practices, and marveling at the extraordinary biodiversity of past ages, these titles highlight the richness of our planet’s biodiversity and remind us of the importance of protecting the wonderful, wild, and beautiful life on Earth.

Asian Biodiversity: An Essential Contributor to Our Beautiful Earth

By Zheping Xu, Xuejuan Chen, and Tian Jiang (National Science Library, Chinese Academy of Sciences)

Biodiversity is essentially everywhere, ubiquitous on Earth’s surface and in every drop of its bodies of water [1]. Biodiversity conservation makes great contributions to the restoration of the earth.

As a continent with the largest area and the most population, Asia holds vast biodiversity, from the equatorial region to the Arctic area, and from the coast of the western Pacific to the borders of Europe and Africa. Here, we introduce several books that review Asian biodiversity, from mammals and insects to some distinctive species from the continent.

Mammals of Eastern Asia (1947) is the first general work on mammals of eastern Asia [2]. The book’s carefully prepared chapters and fine original pen sketches are interesting, useful and invaluable to the amateur as well as the professional zoologist regarding the habitats, relationships, life histories and idiosyncrasies of the widely diversified faunas.

Cerambycidae of Northern Asia (1988) describes the morphology, geographic distribution, and biology of cerambycid beetles in Northern Asia of four sub­families (Prioninae, Disteniinae, Lepturinae, and Aseminae), comprising 124 species. Many cerambycid species are invasive pests of environmental concern, causing severe damage to forests and crops. Long-term field investigations were conducted on the composition and biology of cerambycids in different parts of northern Asia. Tens of thousands of larvae, pupae, and adult insects were raised in the laboratory for experiments. Keys to taxa of the family Cerambycidae based on different developmental stages are presented in this work for the first time. This book provides important information for informing broad theoretical principles and in resolving practical problems of pest infestation in forests.

Asia is home to endemic and highly distinctive focal species. Tracking tigers (Published in 1998) gives a comprehensive overview of the wild status of the Tiger, Asian Elephant, Gaur and Banteng in Indochina. On this basis, it recommends future survey and management needs, and provides background discussion on issues to be addressed by national action plans. The Philippines’ fauna is characterized by large numbers of endemic and highly distinctive species. During the 1980s, the extent of rain-forest habitat destruction became apparent and underscored the need for extensive and detailed documentation of biological diversity to guide development and conservation for the benefit of both wildlife and the human population of the Philippines. The Mammals and birds of Camiguin Island, Philippines, a distinctive center of biodiversity (published in 2006) presents studies of Camiguin Island, a small island province in the Philippines and an ideal natural laboratory in which to investigate many aspects of the evolution and conservation of biological diversity.

Biological species in Asia are important components of Earth’s biodiversity. Biodiversity is closely related to human well-being, but human activities caused rapid changes in biodiversity over the past decades. To restore our Earth, we must identify and assess drivers of biodiversity loss, including habitat change, climate change, invasive alien species, overexploitation, and pollution [1].

[1] Duraiappah, A. K., Naeem, S., Agardy, T., Ash, N. J., Cooper, H. D., Diaz, S., Faith, D. P., Mace, G., McNeely, J. A., Mooney, H. A., Oteng-Yeboah, A. A., Pereira, H. M., Polasky, S., Prip, C., Reid, W. V., Samper, C., Schei, P. J., Scholes, R., Schutyser, F., & Van Jaarsveld, A. (2005). Ecosystems and human well-being: biodiversity synthesis; a report of the Millennium Ecosystem Assessment. World Resources Institute. http://www.millenniumassessment.org/documents/document.354.aspx.pdf.

[2] -S., T. Mammals of Eastern Asia. Nature 161, 188 (1948). https://doi.org/10.1038/161188e0.

Our Southern Birds and Emma Bell Miles: Inspiring Appreciation for and Protection of Birds

By Tomoko Y. Steen, Ph.D. and Alison Kelly, MLIS (Science, Technology & Business Division, Library of Congress)

Emma Bell Miles (1879-1919) was a talented artist, writer and naturalist whose writings reflect her love of the Tennessee mountains where she spent most of her life. In Our Southern Birds, copyrighted in 1919, she recorded her detailed observations and knowledge of the birds of Appalachia, an area that had received little attention in the popular publications on birds until that time. Through this and her other works capturing the essence of natural life in the Southern mountains, Emma Bell Miles drew attention to the importance of preserving biodiversity and habitat.

In the introduction to this, her last book, she stated:

…while the scientific study of birds is beyond most of us, yet an intimate understanding of them and their ways is within reach of everyone, and may enrich life with a new depth of interest… Go out alone in early morning, keep the sun at your back, be careful to do nothing that will startle these timid creatures, and see what you will see.

Our Southern Birds includes many beautiful illustrations by Miles, who, as a young woman, left her home in the mountains to study art in St. Louis. Plagued by homesickness for the mountains, she returned to Appalachia after two years and married a mountaineer. Their marriage was a difficult one, marked by poverty and illness, and she was often the sole supporter of the family by selling her writings, art and poetry.

Written for all levels of readers, this engaging book will appeal to anyone with an interest in birds. Part of the genius of Emma Bell Miles’ work is that she succeeds in presenting not only a careful description of over 100 birds and their habitats, but captures the individual personalities and demeanor of any given species through words and pictures. Her desire to recruit readers to active birdwatching is shown in the inclusion of blank pages for recording observations.

“Shadows from the Past,” the final chapter of the book, mentions several species that are extinct or close to extinction. “Let the disappearance of these winged lives from their one-time haunts lead us to set a higher value on those that remain,” she writes. In poetic language she goes on to describe the tragic extinction of the passenger pigeon, concluding with an appeal that we can learn from the past: “…it is not too late to learn from the mistakes of our fathers, and though we have lost some valuable species, we may yet save others that are following these to extinction”.

In celebration of Earth Day we want to shine a light on Emma Bell Miles, whose skills in observing and recording the natural world around her will inspire readers to appreciate and preserve biodiversity in their own special place on Earth.

Environmental Evaluations Using Birds and Their Habitats

By Samantha Lindgren (University Library, University of Illinois Urbana-Champaign)

In their 1976 book, Environmental Evaluations Using Birds and Their Habitats, Jean and Richard Graber offer practical methods for surveying birds in Illinois with the purpose of curating data for environmental impact statements. Published as one of the Illinois Natural History Survey’s Biological Notes, the book details the data they have collected from these methods, including bird populations and habitat acreage. Throughout the book are also tables, graphs, and images supporting their methods and findings. While the book was published 45 years ago, it came at a time when concerns for environmental protection was just beginning to affect change, and it remains relevant in its advocacy for environmental conservation and restoration.

Earth Day 2021’s theme is Restore Our Earth. This theme resounds throughout the book in details of habitat surveying and restoration. As the authors posit, Illinois is a large state with diverse habitats and niches, some of which are difficult to redevelop once they are threatened. The authors discuss seven categories of gross habitats found throughout the state: forest, shrub, marsh, residential, grassland, small-grain fields, and row-crop fields. Some of these habitat types are more specific to regions of Illinois than others—such as natural marshes occurring most frequently in northeastern Illinois—however each mention comes with information on habitat replacement cost (the time required for restoration of a habitat or community), acreage data, and associated flora and fauna. Alongside this information, the authors also describe their experimental surveying methods. Through these factors, the authors garner concern for habitat conservation and restoration.

The methods discussed for collecting data on bird populations garner this concern as well. As the authors state, “…in the conservation of species we must be concerned for the welfare of all the populations that comprise the species” (11). In the context of this book, this means assigning a fair value to birds when applying an avifaunal index during surveying. However, this sentiment can be applied to Earth Day 2021 as well; in the restoration of our Earth, we must be concerned with the welfare of all aspects of Earth. Moreover, the authors supplement discussions of how and why to collect data on bird populations by speaking in-depth about the derivation of their models, and using them in practice. In this way, the authors are not only advocating for conservation and restoration, they are also providing tangible means to implement conservation and restoration practices.

Environmental Evaluations Using Birds and Their Habitats is a great representation of how to turn concern for Earth’s restoration into meaningful action, and should serve as an example that all levels of skills and fields of interest can be utilized to help Restore Our Earth.

Description of the Skeleton of an Extinct Gigantic Sloth

By Cat O’Carroll (Natural History Museum Library & Archives, London)

In the year 1841, a discovery by M.Pedro de Angelis in Argentina unearthed the skeletal remains of a long extinct species……

Following on from the theme of Earth Day 2021 to Restore Our Earth, and raising issues of climate change, I’ve reflected on a title which highlighted a once extraordinary species which used to roam the earth, Description of the skeleton of an extinct gigantic Sloth, Mylodon robustus, Owen, with observations on … Megatherioid quadrupeds in general by Richard Owen (1842).

Owen, once curator at the Hunterian Museum, Royal College of Surgeons, was later in his career put in charge of the British Museum (Natural History) collections. As a result, he campaigned that a new building was needed to house the ever-expanding collections, which later built in 1881, became the Natural History Museum (NHM) in London as we know it today.

After exhuming the finds of the Mylodon robustus, it was then purchased by the Royal College of Surgeons and shipped over to London. In November 1841, it arrived in many pieces and fragile, in need of much restoring. Fossils discovered by Charles Darwin indicated several species of large quadrupeds had become extinct in South America. Owen compares descriptions of fossil remains of the Mammalia, which were collected by Charles Darwin during the voyage of the Beagle and accounted in The zoology of the voyage of H.M.S. Beagle … during the years 1832-1836.

Megatherium (so named and described by Cuvier, 1795), discovered in the 18th century, was shipped to the Museo Nacional de Ciencias in Madrid. However, if you happen to walk down Fossil Way at the Natural History Museum today, you cannot miss the full Megatherium skeleton cast which stands on display. In terms of scale, Owen compares some of the bones of the Mylodon to that of Megatherium and a full-sized elephant.

The Life of Richard Owen (1894), by his Grandson Rev. Richard Owen, summarizes how Owen was puzzled by the habits of these extinct creatures: “Their teeth showed, by their simple structure, that they lived on vegetable food, and probably on the leaves or tender twigs of trees”. It was hard to see how, like sloths today, they could possibly adapt to climbing trees given their sheer size and weight. Owen conjectured that they may have pulled the branches down from the trees instead of climbing them. Mylodon was also furnished with a “long tongue like a giraffe’s, which would help it to reach its leafy food”.

The NHM Library & Archives holds a large collection of natural history drawings and original artworks amongst its collections. In November of 2019, the Images of Nature Gallery saw the installation of George Johann Scharf’s (1786-1860) watercolour drawing of a Megatherium on full display. Completed in 1842, this one drawing comprises of fourteen sheets approximately 2463 x 5745 mm which Scharf completed for Owen. A MEGA task in itself!

This blog post is part of a series from Smithsonian Libraries highlighting Unearthed, a new collection of paleobiology literature in the Biodiversity Heritage Library curated by Smithsonian Libraries in celebration of the opening of the National Museum of Natural History’s David H. Koch Hall of Fossils – Deep Time exhibit. Follow the series throughout 2019 as Smithsonian scientists and librarians discuss the collection, identify their favorite books within it, and explain the importance of paleobiology literature in research today.

I’m a Deep Time – Peter Buck Fellow in the Department of Paleobiology at the Smithsonian’s National Museum of Natural History where I study the ecology and evolution of prehistoric vertebrates, especially fossil mammals from the Indian subcontinent. The Indian subcontinent has one of the richest mammalian fossil records anywhere in the world. The Siwalik Hills and surrounding regions in Northwest India and Pakistan have a fossil record ranging from about 23 million years ago to about half a million years ago, making this region an ideal place to study how mammalian communities have changed through time.

Fossil mammals in India were first discovered by British explorers and naturalists in the 1830s and 40s. Hugh Falconer, Proby Cautley, W.E. Baker, and H.M. Durand discovered one of the largest deposits of fossil mammals from the Pliocene and Pleistocene (3.6 million years to 0.6 million years) in the region between the rivers Yamuna and Sutlej. These fossils eventually made their way back to the Natural History Museum in London and form one of the most important fossil collections in the world. These collections form the basis of my research on the reassessment of the taxonomy of fossil mammals from India, the biogeography of South Asian mammals, and paleocommunity change.

Understanding the taxonomy of a particular group in the fossil record (the basis for any study on diversity, biogeography, ecology, etc.) requires a review of the various species that have been named. A species is named when a scientist determines that a particular specimen is different enough from other species. This specimen is then classified as the holotype, or voucher specimen for the species. When a new fossil is found, or additional comparisons are made, some described species are determined to be synonymous, and therefore cease to be valid, or sometimes more than one species is found lumped together under the same name. Therefore, revisory studies require an expansive review of the literature, especially the descriptions of the holotypes.

Despite the excellent fossil record, mammals from India have received comparatively little attention from paleontologists in the past. So, to understand the diversity of fossil mammals in the collection, I had to go back to the original papers and books where they were described. In many cases, the species were named by Falconer, but formally described several years later by Richard Lydekker.

Lydekker was a staff member with the Geological Survey of India from 1877-1881, and thereafter came to work at the Natural History Museum, London in 1882. There, he compiled catalogues of fossil mammals, reptiles, amphibians and birds for Henry Woodward, the then Keeper of Fossils at the Natural History Museum. These catalogues are the first formal descriptive documents on Falconer’s Siwalik fossils and are extremely important for any student of fossil mammals. Lydekker also assigned what are known as lectotype specimens for many of the species (the name given to one specimen from a collection which is to be used as a voucher when a holotype has not been designated). Any taxonomic revision would now require a firm understanding of the lectotypes, other specimens referred to that species, and the original description.

These catalogues (Catalogue of the Fossil Mammalia in the British Museum and Catalogue of the fossil Reptilia and Amphibia in the British Museum by Lydekker) are housed in the paleobiology libraries at the National Museum of Natural History and have been digitized by the Biodiversity Heritage Library. They have become an invaluable resource for me in my research. I used the books as a reference to identify key specimens for comparison and used them to revise the taxonomy and biogeography of three-toed horses in the Pliocene of India. I am currently using the catalogues to sort out the taxonomy and diversity of proboscideans from the Pliocene and Pleistocene of the Indian Subcontinent.

In addition to these catalogues, Smithsonian Libraries also has copies of the Palaeontologia Indica Series X, where Lydekker described many other Siwalik species from specimens housed in the collections of the Geological Survey of India in Kolkata; the Fauna Antiqua Sivalensis, the book of Plates that Falconer and Cautley commissioned to illustrate their collection of Siwalik fossils; and Charles Murchison’s Palaeontological Memoirs of Hugh Falconer, which is a collection of Falconer’s notes and papers on the Siwalik fauna, among other related discoveries. These scientific journals and books have made my research possible, not only for my dissertation, but also for other projects that I have since embarked upon.

 

Selected BHL Books from Smithsonian Libraries in Unearthed

Catalogue of the Fossil Mammalia in the British Museum. Part 1-Part 5. 1885-1887. https://www.biodiversitylibrary.org/bibliography/61849

Catalogue of the fossil Reptilia and Amphibia in the British Museum. Part 1-Part 4. 1888-1890. https://www.biodiversitylibrary.org/bibliography/61848.

Indian Tertiary and post Tertiary Vertebrata. Palaeontologia Indica Series X. v.1-v.4. 1874-1902. https://www.biodiversitylibrary.org/bibliography/125505.

Fauna antiqua sivalensis, being the fossil zoology of the Sewalik Hills, in the north of India. 1846. https://www.biodiversitylibrary.org/item/124939.

This blog post is part of a series from Smithsonian Libraries highlighting Unearthed, a new collection of paleobiology literature in the Biodiversity Heritage Library curated by Smithsonian Libraries in celebration of the opening of the National Museum of Natural History’s David H. Koch Hall of Fossils – Deep Time exhibit. Follow the series throughout 2019 as Smithsonian scientists and librarians discuss the collection, identify their favorite books within it, and explain the importance of paleobiology literature in research today.

My name is Michelle Pinsdorf, and I am a paleontologist and preparator of fossil vertebrates in the Smithsonian National Natural History Museum’s Department of Paleobiology. Preparators’ work can cover a wide variety of duties, from fieldwork to discovering new fossil specimens, freeing those specimens from their surrounding host rock in our laboratories, safely housing specimens for research collections, and helping to build exhibits for specimens going out on display. We call it “grave to cradle” work.

Most of the time you’ll find a fossil preparator leaning over a lab bench with a fine tool in hand, peering through a microscope and exposing the details of a fossil that helps researchers identify and publish about it. But for the past five years, my lab colleagues and I have been working on the renovation of the Natural History Museum’s fossil exhibits. This has involved the dismantling of many previously exhibited fossil mounts to allow for the conservation of the fossils and remounting them in new poses and settings. With the significant scientific value of these fossils, a lot of research and planning happens before each individual specimen is worked on.

When research is needed in a museum, a research library is essential! A publication of great help to my work is fortunately quickly accessible to me through the Smithsonian Libraries system and the Biodiversity Heritage Library. One of the crown jewels of the Museum’s collections is the nearly complete skeleton of the carnivorous dinosaur Ceratosaurus nasicornis. It is the most complete skeleton of this species found to date, originally named by Othniel Charles Marsh.

When the specimen was mounted for exhibit at the Smithsonian in 1911, it was fully described by curator Charles Whitney Gilmore, and included in the publication Osteology of the carnivorous Dinosauria in the United States National Museum: with special reference to the genera Antrodemus (Allosaurus) and Ceratosaurus, in Bulletin of the United States National Museum, volume 110. Gilmore provided detailed descriptions and illustrations of this unique specimen, figured prior to it being partially embedded in a display plaque for exhibit. Those figures and measurements proved essential to my work to re-prepare the specimen out of the plaster plaque, exposing a side of the fossils no one since Gilmore’s time had been able to see.

This fascinating specimen now gets to serve science in multiple ways. With each bone removed and cleaned, the fossils have been once again made available to paleontologists for study. Each bone was molded and cast, so that the casts could be reassembled in a dynamic new pose for public display in the new Deep Time fossil exhibit halls. The digitization of Gilmore’s publication allowed for me to quickly reference it from my workstation, my home computer, even on my phone. And the physical copy is also close at hand in the Natural History Museum itself, for when I need the kind of inspiration that comes with smelling old paper and seeing neat rows of bindings.

I look forward to seeing what new research will come from my work with Ceratosaurus, and the reactions of museum visitors when they get to see the new mount for the first time.

This blog post is part of a series from Smithsonian Libraries highlighting Unearthed, a new collection of paleobiology literature in the Biodiversity Heritage Library curated by Smithsonian Libraries in celebration of the opening of the National Museum of Natural History’s David H. Koch Hall of Fossils – Deep Time exhibit. Follow the series throughout 2019 as Smithsonian scientists and librarians discuss the collection, identify their favorite books within it, and explain the importance of paleobiology literature in research today.

I’m Bonnie Felts, and I am a library technician for Smithsonian Libraries at the Natural History Museum. What most people don’t realize about our museum is that we have a total of 11 separate library locations, and I work with five of the collections. I am primarily responsible for the Vertebrate Paleontology library, which requires fielding reference questions, purchasing materials pertinent to the collection, and the overall care of the materials. Although in numbers, the library is relatively small compared to other libraries in our building, it is one of the most comprehensive Vertebrate Paleontology literature collections in the world.

Vertebrate Paleontology concentrates on the biological history of animals with backbones that have been fossilized. The first thing people would think of when studying Vertebrate Paleontology would be dinosaurs! Yes, there are many publications about dinosaurs in our library, but we also have information about fossilized fish, mammals, birds, reptiles, and even humans. The scope of the collection includes systematic paleontology and paleozoology of chordates and vertebrates of the Paleozoic, Mesozoic, Tertiary, and Quaternary periods, as well as physical geography and stratigraphy.  Although much of the collection is very science based, we have also included books targeted towards non-scientists to assist the education programs supported by the Natural History Museum. We also select paleoart books, which give us a visual depiction using scientific evidence of what prehistoric life was like when fossilized remains were alive.

With the opening of the National Museum of Natural History’s David H. Koch Hall of Fossils – Deep Time exhibit this past June, the Smithsonian Libraries thought it would be ideal to also showcase the library collections that support the scientists in their research that are available online through the Biodiversity Heritage Library. This is the greatest perk of having BHL available as a resource for our researchers, but it’s a free service available worldwide to anyone with an internet connection!

The Biodiversity Heritage Library (BHL) is an open access, multi-library collaboration that is headquartered at the Smithsonian Libraries. Although BHL covers a myriad of subjects in biodiversity, it did not originally include much literature in Paleobiology. As BHL continues to grow and expand its collection, so does the need to expand its subject areas. How did we get the animals we have today? What was their climate like thousands or even millions of years ago? The information that modern scientists are looking at today may have been rooted in what happened years before the existence of man or during the early years of humanity. It makes sense to include information about extinct animals and plants when looking at biodiversity.

Some of the many interesting books that the Smithsonian Libraries holds in the Vertebrate library that are also available on the Biodiversity Heritage Library are part of a series called Die Säugetiere des Schweizerischen Eocaens: Critischer Catalog der Materialien (in English “The Mammals of the Swiss Eocene: Critical Catalog of the Materials”). These books were written by the late 19^th/early 20^th century Swiss vertebrate paleontologist Hans Georg Stehlin (1870-1941), who spent his career at the Natural History Museum in Basal. Stehlin is credited for creating the term “Grande Coupure,” translating literally to “great break,” which refers to a major extinction event when the Eocene epoch ended and the Oligocene epoch began around 33.9 million years ago. This extinction event coincided with a cooler climate that led to drastic changes in terrestrial flora and fauna in Eurasia, namely the extinction of many European vertebrates and the movement of Asiatic taxa to Europe.

The books contain descriptions of fossilized bones and teeth from many European museum and university collections that Stehlin had studied. They were also published in the series Abhandlungen der schweizerischen paläontologischen Gesellschaft (Treatises of the Swiss paleontological society). The images contained within the volumes depict the teeth and bones of a wide range of Eocene mammals. This major study remains a classic reference for students of the evolutionary history of mammals.

This blog post is part of a series from Smithsonian Libraries highlighting Unearthed, a new collection of paleobiology literature in the Biodiversity Heritage Library curated by Smithsonian Libraries in celebration of the opening of the National Museum of Natural History’s David H. Koch Hall of Fossils – Deep Time exhibit. Follow the series throughout 2019 as Smithsonian scientists and librarians discuss the collection, identify their favorite books within it, and explain the importance of paleobiology literature in research today.

I study sloths, and as popular as they have become on the internet, the thing most people do not realize is that we are living in a world majorly deprived of most types of sloth. Today there are only two types of sloths: two-fingered (genus Choloepus) and three-fingered (genus Bradypus). (You may have heard them referred to a two-toed and three-toed, but they both have three digits on their hind limb, so the difference is on the forelimb, in other words, their hand, hence: fingers.) There are only a few species of each kind of sloth and they all live in the trees of tropical rainforests in Central and South America.

But back in prehistoric times, there were many types of sloths: more than 80 genera across five different families. They lived as far north as the Yukon Territory and Alaska, as far south as Patagonia, and stretched from coast to coast in the United States and even colonized islands throughout the Caribbean. The smallest of these fossil sloths were still bigger than any sloth alive today, and the biggest extinct sloths were the size of modern elephants (but could probably walk around on two legs like an awkward bear). All this means there is a lot to learn about the sloths that are no longer with us.

The earliest scientific description of a fossil sloth was written by then Vice President Thomas Jefferson, based on some bones found in a cave in what was then Virginia, now West Virginia, by some men mining saltpeter (potassium nitrate), which crystalizes out of deposits of bat guano and was an important economic resource as a major chemical component of gunpowder. The bones were given to the land owner, who knew that Thomas Jefferson had an interest in Natural History, and so he had them sent to Monticello.

Jefferson presented his findings at the American Philosophical Society in Philadelphia in 1797, which was then published in writing in 1799.[1] Jefferson interpreted the animal as something similar to a large lion, though in reality probably closer in size to a large bear, and named the animal Megalonyx, which means “great claw”, because, like living sloths, ground sloths also had impressive claws.

In addition to thinking this animal was some great hunter, Jefferson did not like the idea that this animal was extinct (remember, this is still half a century before the publication of Darwin’s The Origin of Species [2]). After working through some of the logic of his argument, Jefferson concludes, “If this animal then has once existed, it is probable on this general view of the movements of nature that he still exists…” According to a possibly apocryphal tale, when Jefferson was preparing Lewis and Clark for their journey to the interior of the continent, he showed them the massive claws of Megalonyx and warned them to stay vigilant should the beast still be stalking the forests of the then still “untamed” parts of Western Virginia, Ohio, and beyond.

Even 100 years after Thomas Jefferson’s first description, there were questions as to whether or not relatives of Megalonyx still existed in the far reaches of South America [3], owing in part to some amazingly-preserved mummified sloths that look “recent” compared to many fossils, with bits of skin and fur still clinging to desiccated bone. As far as we can tell, we sadly live in a world bereft of ground sloths, but in some ways, we are still trying to answer some of the earliest questions Jefferson and others had about their no longer observable lifestyles.

For example, there is a fossil site in South America that has several different types of ground sloths and seemingly no predators to eat them, leading to a question of how so many large herbivores avoided scouring the plant life bare. One paleontologist has proposed that the elephant-sized Megatherium, one of the largest ground sloths ever to evolve, may have scavenged or even hunted the smaller animals in their range, harkening back to Jefferson’s lion-esque Megalonyx. While this seems implausible, it is an idea and one that we can try to test, which is where my research comes in.

One focus of my research is what ground sloths ate. Paleontologists use a lot of different techniques to determine diet in animals we cannot directly observe anymore, such as the type of teeth the animal had and the other types of fossils found in the same area (including fossil poop if we can find any!). We also use less obvious methods like the microscopic scratches seen on the chewing surfaces of teeth, or even the actual atoms in the fossils themselves (because those atoms ultimately come from the atoms of food, so you really are what you eat).

Sloth teeth are softer than normal mammal teeth, and grow continuously throughout their entire lives, which makes them better suited to the persistent chewing of leafy browse or grasses than the tearing of flesh and crunching of bone. Two species of ground sloth have been found in caves associated with fossil feces (sometimes called coprolites), and when taken apart or analyzed chemically, the feces only shows evidence of poorly digested plants. And when we look at the ratios of different isotopes trapped in bone, teeth, and even the poop, we see evidence of a mix of plants in the diet, but little evidence of animal protein being eaten.

One avenue of my research is testing some of these fossil findings against modern sloths, to make sure that our interpretations of these data are correct. Two-fingered sloths are often given a little bit of dog food in captivity, whereas three-fingered sloths are not, so I have actually been able to chemically test the isotopes of a slightly omnivorous sloth against a pure herbivore to see how that compares to the fossils!

So, from these lines of evidence we can conclude that ground sloths were herbivores much like modern sloths, and while there is much more research to be done, it is incredibly helpful to be able to look back to the earliest days of paleontology through the Smithsonian Libraries’ collections and see how the thinking about sloths has changed drastically even as we still work to answer some of the earliest questions about these magnificent, lazy, internet-famous beasts.

References

[1] Jefferson, Thomas. 1799. “A Memoir on the Discovery of Certain Bones of a Quadruped of the Clawed Kind in the Western Part of Virginia.” Transactions of the American Philosophical Society, v. 4.

[2] Darwin, Charles. 1859. On the Origin of Species. London: John Murray.

[3] Ameghino, Florentino. 1898. “An Existing Ground-Sloth in Patagonia.” Natural Science, v. 13.