The shell of this nautilus at the Smithsonian’s National Zoo clearly shows the deformity–area characterized by black bands–that started after it began living in an aquarium. (Photo by Mehgan Murphy)

In the wild, wide milk chocolate-brown stripes adorn the beautiful smooth, white shells of the chambered nautilus, a deep-diving mollusk from the Indo-Pacific Ocean. But when placed in an aquarium, the new surfaces of shell these animals produce become thick, rough and stripped with a black substance. Why this ugly deformity occurs is a mystery that aquarists have puzzled over since the 1970s.

“We wondered if they are not getting something in their diet in aquaria or if something in the water is not available to them,” explains Alan Peters, a curator at the Smithsonian’s National Zoo in Washington, D.C.  “Aquarists have long known that in an aquarium the normal pattern of the nautilus’ shell never fully returns.”

This scanning electron microscope image (top) shows the orderly crystalline structure in a wild formed Nautilus. The disorderly crystalline structure of the aquarium-formed shell is at bottom.

Calling upon a variety of scientific techniques, including stable isotope mass spectronomy, scanning electron microscopy, micro X-ray fluorescence and X-ray diffraction, a team of researchers including Peters recently took a close look at this shell deformity. Using the shells of nautiluses that had first lived in the ocean and then been placed in an aquarium they carefully examined and compared the chemical and physical structure of portions of both the old and new shell.

What they first found under a scanning electron microscope was that the crystalline structure of aquarium-formed shell was less ordered, poorly defined and without a clearly defined shape or form.

Next, chemical analysis revealed that the black deposits in aquarium-produced shell contain excess amounts of copper, zinc and bromide and decreased amounts of calcium and magnesium.

High amounts of copper, zinc and bromide “point to the role that proteins play in the construction of the shell,” and do not appear related to diet or tank-water chemistry, Peters and colleagues write in a recent paper in the journal Zoo Biology.

When a nautilus is removed from its natural environment and placed in an aquarium, it experiences “environmental stress such as changed pressure, temperature and ultraviolet light patterns.” That may trigger an attempt to reinforce their aquarium-formed shell, compensating for a weakened crystalline structure.

The shell of this aquarium-living nautilus clearly shows the difference between its wild-produced and captive-produced shell. (Flickr photo by Michael Bentley)

In the end, the scientists were unable to reach a conclusion as to just what what causes a nautilus shell to deform in an aquarium. “We have all kinds of theories,” Peters says “but so far we are unable to confirm any of them.” The researchers next plan to conduct experiments measuring the impact of temperature and light on the production of black areas of shell, as well as the function of proteins in wild vs. captive  shell production.

Nautiluses appeared on earth about 500 million years ago during the Cambrian Explosion—they were jet-propelling themselves through ancient seas 265 million years before dinosaurs inhabited the Earth. They have remained mostly unchanged for millions of years.

Today the animals are characterized by experts as being on the “knife-edge” of extinction, overfished across their range because of their beautiful shells. A recent survey by the U.S. Fish and Wildlife Service disclosed that the U.S. imports some 100,000 nautilus shells each year. Their numbers in the Philippines have dropped by 80 percent since the 1980s. International trade sanctions against the capture and trade of the nautilus are virtually nonexistent.

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Smithsonian intern Catalina Suarez Gomez excavating a fossil in the Cerrejón coal mine in Colombia.

What do you want to be when you grow up? Would you want to explore the world searching for long lost creatures of our past? That’s exactly what many of our paleontologists and expert fossil hunters do at the Smithsonian. Check out these five amazing finds in celebration of National Fossil Day, October 15th. If you get inspired, you too can be become a National Fossil Day paleontologist at the Smithsonian’s National Museum of Natural History. Could you imagine if you found one of these exciting fossils?

1.    A giant prehistoric turtle that could chomp crocodiles!

Paleontologists were astounded when they found a turtle the size of a smart car with a head roughly the size of a regulation NFL football. Named Carbonemys cofrinii, after the Colombian coal mine where it was found, the giant turtle lived 5 million years after the dinosaurs vanished. This was a period when giant varieties of many different reptiles—including Titanoboa cerrejonensis, the largest snake ever discovered lived—in this part of South America. Read more...

Edwin Cadena, the scientist who discovered the fossil of Carbonemys, poses next to its reconstructed fossil shell. (Photo courtesy Dan Ksepka, NC State University)

2.    Details of an ancient shark attack preserved in fossil whale bone.

Three-to-four million years ago during the Pliocene a whale was attacked, most likely by a mega-toothed shark Carcharocles megalodon. Paleontologists found evidence of this animal behavior in a fragment of whale rib dug up in a North Carolina. Three tooth marks on the rib indicate the whale was severely bitten by a large predator, with 6-centimeter (2.4-inch) spacing between the tooth marks. Scientists know the whale survived because “most of the fossil fragment is covered with a type of bone known as woven bone, which forms rapidly in response to localized infection.” Read more…

Whale bone fossil showing the three tooth marks from a shark. (Photo by Stephen Godfrey)

3. A new species of large, feathered dinosaur that looked like a giant scary chicken.

Sometimes paleontologists find amazing new species not by sifting through dirt, but by digging around in the drawers of museums. That’s what happened with Anzu wyliei, a strange, bird-like creature that has a bony crest on top of a beaky head and a long lizard-like tail. Scientists from the Smithsonian’s National Museum of Natural History, the Carnegie Museum of Natural History and the University of Utah discovered the species in 2014 and named it after a feathered demon from ancient Mesopotamian mythology. Read more...

An illustration of Anzu wyliei shows several striking anatomical features of the large, feathered dinosaur, including its long tail, feathered arms, toothless beak and a tall crest on the top of its skull. The new species was identified by a team of Smithsonian scientists in collaboration with the Carnegie Museum of Natural History and University of Utah from three partial skeletons collected from the Hell Creek Formation, providing detailed evidence of North American oviraptorosaurs for the first time. (Illustration by Mark Klingler, Carnegie Museum of Natural History)

4. Blood molecules preserved for millions of years in the abdomen of a fossil mosquito.

It sounds like the beginning of Jurassic Park. A mosquito ate its last blood meal 46 million years ago before it was fossilized at the bottom of an ancient pond. Scientists from the Smithsonian’s National Museum of Natural History discovered blood molecules from the mosquito’s last supper very much intact inside the fossil, the first clear evidence that some organic molecules can be preserved in a fossil of this age. What else can we find from these fossilized mosquitoes? Read more...

This image is a microscope photograph of a piece of shale from the Kishenehn Formation in northwestern Montana containing the fossil of a blood-engorged mosquito. Scientists from the Smithsonian and the Natural History Museum in London have discovered biomolecules from the blood in the mosquito’s abdomen that have been preserved for 46 million years. (Photo by Tim Rose)

5. A new fossil whale species that makes us question why narwhals and belugas live only in cold water today.

When scientists from the Smithsonian’s National Museum of Natural History and Howard University found a new species of toothed whale that lived some 3-4 million years ago, it raised some questions. A nearly complete skull of the new species, Bohaskaia monodontoides, was found in 1969 in a mine near Hampton, Va. Only after the researchers looked at the skull in 2010 did they realize not only was it a different species to the narwhals and belugas that live today, but unlike modern whales it lived in temperate and tropical regions. Read more…

An artist’s conception of Bohaskaia monodontoides, foreground. Behind and above are a beluga and narwhal. (Artwork by Carl Buell)

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Left-handed snails, giant wombats, spiny trilobites, zombie ants, glyptodonts…these are a few of the fascinating animals and plants whose fossils spring to life across the pages of A History of Life in 100 Fossils, a new offering from Smithsonian Books.

Selected from the collections of the Smithsonian’s National Museum of Natural History in Washington, D.C., and the Natural History Museum in London, each fossil is beautifully photographed and explored in-depth with a captivating description of its importance to the story of evolution and life on Earth. Organized chronologically from the Precambrian through the Paleozoic, Mesozoic and Cenozoic eras, the book reveals the remarkable and persistent unfolding of fantastic life forms across the Earth as revealed in the fossil record.

Co-authors Aaron O’Dea of the Smithsonian Tropical Research Institute in Panama and Paul Taylor of the Natural History Museum in London carefully compiled the images in this book from hundreds of possibilities.

One of the first and oldest entries, a 3.5 billion-year-old rusty red stromatolite fossil, is arguably the most important. Dominating the world’s oceans for a staggering 3 billion years, stromatolites eventually filled the atmosphere with enough oxygen to enable the rise of complex oxygen-breathing organisms.

Aaron O’Dea

The oddest entry is a spiral bezoar (fossilized feces) recovered from ancient sea sediments and which once was imbedded in the intestine of a prehistoric shark.

Most touching: The Laetoli footprints from Tanzania, left in a matter of seconds some 3.5 million years ago, appear to show the path of a small family of early hominins, Australopithecus afarensis, wandering through a volcano’s devastation.

Steller’s sea cow wins as the saddest entry, “a sad tale of a once magnificent beast driven to extinction by hunting,” O’Dea, a paleobiologist, says. “Without its fossil record we would have had no idea that the animal was naturally widely abundant until a few thousand years of hunting whittled them away to almost nothing.”

“Onychonycteris finneyi,” a remarkably complete bat fossil found in 52-million-year-old lake sediments in Wyoming.

Other fossils examined include Cambrian worms from China that provide a window on early animal life in the sea, ancient insects encapsulated in amber, the first fossil bird Archaeopteryx and the last ancestor of humankind.

Writing A History of Life in 100 Fossils with Taylor “was a fantastic experience,” O’Dea observes in his blog. “Researching in detail about fossil groups I had previously paid little attention to, spinning evolutionary tales with a single slab of rock and crafting them in a way that could be accessible to all. As I wrote I tried to weave all the big biological themes into the book; natural selection, convergent evolution, sexual selection, extinction, the origin of life and even parasitism.”

A History of Life in 100 Fossils is brimming with epic tales of survival and migration, evolution and destruction once concealed in the buried remains of animals and plants that lived long ago.

Available from Smithsonian Books October 14.

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Nearly 20 years since Kennewick Man was serendipitously discovered along the banks of the Columbia River in Washington State, the scientific saga of his life and legacy is being released. A new book Kennewick Man: The Scientific Investigation of an Ancient American Skeleton, co-edited by forensic anthropologists Douglas Owsley at the Smithsonian Institution and Richard Jantz at the University of Tennessee, will be published this September by Texas A&M University Press. It provides the most thorough analysis of any Paleoamerican skeleton to date.

(Image courtesy Texas A&M University Press. Detail from sculpted bust of Kennewick Man by StudioEIS with Jiwoong Cheh; based on forensic facial reconstruction by Amanda Danning; image provided by StudioEIS.)

The findings reveal key details about Kennewick Man’s identity, including where he lived nearly 9,000 years ago and his approximate age at death, lifestyle and relationship to ancient and modern human populations. However, these conclusions stretch beyond the life of just one individual. They provide scientists with a new window into the ancient migration of people to the New World and the experiences of early Americans.

Kennewick Man was about 40 years old at the time of his death, the cause of which remains a mystery. Other humans buried him at the gravesite where his body was found. Kennewick Man’s skull morphology does not easily fit into any major populations today, but most closely resembles Pacific Rim populations such as the Ainu of Japan and Polynesians, reflecting deep roots in coastal Asian groups. A facial reconstruction of Kennewick Man housed at the National Museum of Natural History lends a deeper understanding of what he may have looked like.

“The human skeleton teaches us a wealth of information about human population dynamics across time,” said Owsley, division head of physical anthropology at the National Museum of Natural History. “Kennewick Man has become a teacher for all ages, acting as an informative ambassador to the ancient past in North America.”

Owsley and his colleagues conducted an extensive, interdisciplinary analysis of Kennewick Man’s remains with the support of about 50 physical and forensic anthropologists, archaeologists, geologists, geochemists and others, who studied the nearly 300 bones and fragments that were discovered in July 1996.

The resulting studies concluded that Kennewick Man was tall for his time at 5 feet 7 inches and well-muscled. His 163-pound, wide-bodied frame helped him navigate the steppe-like habitat of his surroundings along the northwest coast of North America where he hunted and fished. Kennewick Man, called the “Ancient One” by American Indians, may have lived among big-game animals such as deer, pronghorn antelope and bighorn sheep but primarily consumed fish and marine mammals. This diet, along with Kennewick Man’s reliance on glacial meltwater in rivers, is consistent with the lifestyle of a traveler from the northern part of the continent who made his way down the Pacific coast to Washington state.

His hand, arm and shoulder bones suggest that he was right handed and was adept at flint knapping and throwing spears with an atlatl. Kennewick Man survived two major injuries during his life, including six broken ribs from blunt force trauma to the chest and an adversarial encounter with a spear. The resulting impact from the spear left a stone projectile point permanently lodged in Kennewick Man’s pelvis for multiple years during his lifetime.

In addition to discussing the life of Kennewick Man, the book sheds light on other ancient and highly unique burials. There is a chapter about On Your Knees Cave in southeast Alaska where the bear-scavenged remains of a 10,200-year-old young adult male were found, and another featuring Horn Shelter #2 in central Texas, which contained skeletons of a young child and man buried with distinctive cultural items that identify the man as a shaman. The analyses of these sites provide a broader context for understanding Kennewick Man’s place in the Paleoamerican world, a time period that has produced few well-preserved, nearly complete skeletons.

Owsley and his colleagues plan to continue their study of Kennewick Man in the future to answer remaining questions about his identity. Research on Kennewick Man took place over the course of two visits and 16 days in 2005 and 2006 following a court ruling permitting the study of the remains, which are currently housed at the Burke Museum of Natural History and Culture at the University of Washington in Seattle.

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Today the Smithsonian launches its Transcription Center website to the public. The website is designed to leverage the power of crowds to help the Smithsonian unlock the content inside thousands of digitized images of documents, such as handwritten Civil War journals, personal letters from famous artists, 100-year-old botany specimen labels and examples of early American currency.

A tray of bumble bees from the National Museum of Natural History’s bee collection awaits digitization. The museum is digitizing all 45,000 specimens in its collection and using virtual volunteers to help transcribe important data found on each specimen’s tag. This data will help scientists studying declining bee populations in North America

The Smithsonian has already produced digital images for millions of objects, specimens and documents in its collection. Many of the digitized documents are handwritten or have text that computers cannot easily decipher. Transcription by humans is the only way to make the text of these items searchable, which will open them up for endless opportunities for research and discovery.

“We are thrilled to invite the public to be our partners in the creation of knowledge to help open our resources for professional and casual researchers to make new discoveries,” said Smithsonian Secretary Wayne Clough. “For years, the vast resources of the Smithsonian were powered by the pen; they can now be powered by the pixel.”

The Smithsonian’s collection is so vast that transcribing its content using its own staff could take decades. By harnessing the power of online volunteers that goal can become a reality. During the past year of beta testing with nearly 1,000 volunteers, the Transcription Center completed more than 13,000 pages of transcription. In one instance—transcribing the personal correspondence of members of the Monuments Men held in the Smithsonian’s Archives of American Art collection—49 volunteers finished the 200-page project in just one week. By some estimates, the volunteers are completing in a couple of days what it would take the Smithsonian months to complete without their help. Once a document is done, the work is reviewed by another volunteer before it is certified for accuracy by a Smithsonian expert.

Projects selected for transcription during the beta-test phase were chosen due to high demand from scientists, researchers and enthusiasts for certain items that presented accessibility challenges. For example, the Smithsonian’s National Museum of Natural History has one of the world’s largest bumble bee collections—nearly 45,000 specimens. Information about each bee, such as where it was collected and when it was collected, is extremely valuable to scientists studying the rapid decline of bee populations during the past few decades. The only way to obtain this information before digitization and transcription would be for a scientist to come to the museum and read each tiny, handwritten label (often as small as 3 millimeters by 7 millimeters) and record the information. Now, with the information digitized and transcribed, scientists anywhere in the world can understand more about the population history of the bumble bee and its recent population decline. The bumble bee transcription project is currently one of the highlighted projects on the site.

Curators at the Archives Center at the Smithsonian’s National Museum of American History chose to contribute the diary of Earl Shaffer, the first man to hike the entire length of the Appalachian Trail. Hiking enthusiasts, naturalists and other researchers frequently consult this now fragile document. Once the diary was digitized and uploaded to the Transcription Center, members of the online Reddit community devoted to the trail promoted the project. As a result, all 121 pages were transcribed in two weeks. The diary is now available for download, allowing the public to read, study and search for key words or landmarks and reducing the need for researchers to handle the delicate artifact.

How to Volunteer

Volunteers can register online today to help the Smithsonian transcribe a variety of projects relating to art, history, culture and science, including:

For art lovers: Handwritten personal letters of artists from the Archives of American Art
Read and transcribe personal letters from artists such as Mary Cassatt, Grandma Moses and Claes Oldenburg. Transcriptions of these letters will be part of the Archives forthcoming book The Art of Handwriting. In an age of emails, texts and tweets, when handwritten letters have ceased to be a primary mode of person-to-person communication, this book will explore what can be learned from the handwriting of artists.

For armchair archeologists: Field reports from Langdon Warner
Langdon Warner was an American archeologist and art historian who specialized in East Asian art. He was also one of the Monuments Men who worked to protect monuments and cultural treasures in Japan during World War II. A professor at Harvard and Curator of Oriental Art at Harvard’s Fogg Museum, he is reputed to be one of the models for Steven Spielberg’s Indiana Jones.

For bird lovers: Observation notebooks of James Eike
James Eike was a Virginia bird watcher who kept impeccably detailed field observations of birds and the weather nearly every day from 1960 to 1983 near his home in Northern Virginia. In addition to being an important resource for ecologists, it also includes tidbits of cultural events from that time, including the 1969 moon landing.

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The National Museum of Natural History in Washington, D.C., has closed its Dinosaur Hall for a five-year renovation. But before the overhaul can begin, the resident dinosaurs need to be removed. A highly specialized crew is dismantling a meat-eating dinosaur called Allosaurus piece by piece.

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Many traits unique to humans were long thought to have originated in the genus Homo between 2.4 and 1.8 million years ago in Africa. A large brain, long legs and the ability to craft tools along with prolonged maturation periods were all thought to have evolved together at the start of the Homo lineage as African grasslands expanded and Earth’s climate became cooler and drier. Now a paper published in Science today outlines a new theory that the traits that have allowed humans to adapt and thrive in a variety of varying climate conditions evolved in Africa in a piecemeal fashion and at separate times.

These fossil skulls, representing pre-erectus Homo and Homo erectus, exhibit diverse traits and indicate that the early diversification of the human genus was a period of morphological experimentation. (Photos: Kenyan fossil casts – Chip Clark, Smithsonian Human Origins Program; Dmanisi Skull 5 – Guram, Bumbiashvili, Georgian National Museum)

New climate and fossil evidence analyzed by a team of researchers suggests that these traits did not arise as previously thought, in a single package in response to one specific climatic trend. Rather, these defining Homo traits developed over a much wider time span in response to a much more climatically variable environment, with some traits evolving in earlier Australopithecus ancestors between 3 and 4 million years ago and others emerging in Homo significantly later. The research team includes Smithsonian paleoanthropologist Richard Potts, Susan Antón, professor of anthropology at New York University, and Leslie Aiello, president of the Wenner-Gren Foundation for Anthropological Research.

“The traits that typify our own species Homo sapiens weren’t there right at the beginning of the evolution of the Homo genus; instead, humanness evolved in much more of a mosaic pattern,” explains Potts, curator of anthropology and director of the Human Origins Program at the Smithsonian’s National Museum of Natural History.

“Climate instability we have found would have translated to major shifts in resource availability including fresh water and food. This instability favored genetic traits and behaviors that promoted the evolution of flexibility in how well early humans responded to change. This is quite different from the idea of adaptation to a particular ancestral habitat and is a very important change in our thinking” Potts added.

A large brain, long legs, the ability to craft tools and prolonged maturation periods were all thought to have evolved together at the start of the Homo lineage in response to the Earth’s changing climate; however, scientists now have evidence that these traits arose separately rather than as a single package. (Image courtesy Rick Potts, Susan Antón and Leslie Aiello)

To reach these conclusions, the team took an innovative research approach, including developing a new climate framework based on the Earth’s astronomical cycles from 2.5 million to 1.5 million years ago. This paleoclimatic data was integrated with new fossils and understandings of the genus Homo, archaeological remains and biological studies of a wide range of mammals (including humans). However, it was the recently discovered skeletons of Australopithecus sediba (~1.98 Ma) from Malapa, South Africa, that really cemented the idea for Potts that the evolution of the Homo genus involved a period of evolutionary experimentation and mixing of traits.

“A. sediba possesses a bizarre combination of features. It has a really small brain, the size of a chimpanzee’s, but also a human-like hand. It also has aspects of the face that resemble the genus Homo but has a foot that doesn’t look anything like the genus” Potts explains. “This makes sense from the standpoint of the environment at the time, where habitats were fluctuating between more wooded and more open grassland landscapes due to shifting intensity of wet and dry periods. Small populations would have become isolated at times and later merged, which would have lead to a novel evolutionary combinations of traits.”

This chart depicts hominin evolution from 3.0-1.5 million years ago and reflects the diversity of early human species and behaviors that were critical to how early Homo adapted to variable habitats, a trait that allows people today to occupy diverse habitats around the world. (Image courtesy Rick Potts, Susan Antón and Leslie Aiello)

We live today in a very unusual period where there is only one species that exists in our evolutionary tree. Multiple species of Homo are known to have lived concurrently during the earlier time of morphological experimentation. Along with the climate and fossil data, evidence from ancient stone tools, isotopes found in teeth and cut marks found on animal bones came together in this research to depict how these species may have coexisted.

“Taken together, these data suggest that species of early Homo were more flexible in their dietary choices than other species,” Aiello said. “Their flexible diet—probably containing meat—was aided by stone tool-assisted foraging that allowed our ancestors to exploit a range of resources.”

Evolutionary and historic climate studies not only shed light on how we came to be, says Potts, but also give us a broader view of current climate change problems.

“These kinds of studies show that we do live on an unstable Earth in terms of its climate, however, humans are adding totally new influences to the environment in ways perhaps more precarious than we even thought.”

“Human features were selected for adaptability, but our earlier ancestors show there have always been limits to that. Our astonishing ability to adjust to new and changing circumstances is something that I think gives us some hope for the future,” Potts says.

“The question ahead for human beings is whether we can use our capacity for technology, culture and social interaction to a sufficient extent to avoid the kinds of precarious situations even members of our own evolutionary history faced in their past,” he added.

The team concluded that the flexibility demonstrated by our ancestors to adjust to changing conditions ultimately enabled the earliest species of Homo to vary, survive and begin spreading from Africa to Eurasia 1.85 million years ago. This flexibility continues to be a hallmark of human biology today, and one that ultimately underpins the ability to occupy diverse habitats throughout the world.

Future research on new fossil and archaeological finds will need to focus on identifying specific adaptive features that originated with early Homo, which will yield a deeper understanding of human evolution.

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Here at Smithsonian Science we are celebrating Sloth Week with four little-known facts about sloths, some of which we found in the Smithsonian’s very own collections!

1. The Smithsonian has a collection of fossilized sloth poop

What do you keep in your drawers? If you pull open a drawer at the Smithsonian’s National Museum of Natural History, don’t be surprised if you find fossilized sloth poop. This poop, or coprolite as it is scientifically known, is from an extinct species called the Shasta ground sloth, Nothrotherium shastense. It was found in Rampart (Sloth) Cave in Arizona, and is estimated to be 10,400 years old. Scientists have used this dried excrement to analyze not only the diet of these extinct animals but also the ancient parasites they carried.

Fossilized excrement from the Shasta ground sloth, “Nothrotherium shastense,” in the collection of the Smithsonian’s National Museum of Natural History. (Photo by Micaela Jemison)

“DNA from the parasites we find in the sloth poop can tell us many things,” explains David Bohaska, from the museum’s Paleobiology Department. “Some researchers have used it to look for viruses or bacteria carried by the parasites in an attempt to see if there is a link between disease and mass extinctions in the past.”

2. Sloths once lived in the sea

A prehistoric aquatic sloth in a swimming pose. (Illustration by Carl Buell)

Aquatic sloths did exist! These animals were quite different from the sloths alive today that hang and climb around in the high rainforest canopy. Aquatic sloths, as their name suggests, spent the majority of their time in the sea, swimming and diving to eat sea grasses or algae. They lived 4 to 9 million years ago along the coasts of Chile and Peru, where the coastal landscape borders or adjoins a vast desert with little vegetation, likely forcing the sloths to adapt to a diet from the ocean.

“Recent studies have shown that these sloths were developing increased bone density in their ribs,” explains Jorge Velez-Juarbe, curator of Marine Mammals at the Natural History Museum of Los Angeles. “This extra density or weight could have helped them in their aquatic lifestyle by allowing them to dive down much easier to reach their aquatic foods.” Although aquatic sloths are extinct today, their modern relatives have retained their swimming ability. Their weak hind legs and long claws, while well adapted for life hanging in the trees, makes movement on land difficult. But once they are in the water, sloths are surprisingly good swimmers, able to stroke efficiently with their long arms.

As its mother enters the water, this young three toed sloth knows to crawl onto her back. This sloth species is known as “Bradypus variegatus.” (Photo by Louise Emmons)

3. Early humans may have hunted giant sloths.

Could you imagine facing off with a 23-foot-tall giant sloth? Our early ancestors may have done just that. Learn more about how this meeting may have occurred with Kirk Johnson, Sant Director of the Smithsonian’s National Museum of Natural History, in the video below.

4. Thomas Jefferson was involved in the discovery of an extinct sloth species

President Thomas Jefferson was widely known to have had a keen interest in fossils, and regularly received fossils from friends and acquaintances. One such gift, from Col. John Stuart of Greenbier County, Virginia (now West Virginia), was a fossil excavated from Cromer Cave in 1796. He described it to Jefferson as “..bones of a tremendous animal of the clawed kind lately found…might afford you some amusement.”

Jefferson studied the bones and drafted a scientific paper to be submitted to the American Philosophical Society. He reached the conclusion that the bones were from an animal “of the lion kind, but of most exaggerated size,” which he called “the Great-claw or Megalonyx.”

Jefferson was waiting on one last piece, the thighbone, to be sent to him to confirm his conclusions on its size, when he was elected to two important offices: vice president of the United States under John Adams, and president of the American Philosophical Society. With his induction as Society president approaching, Jefferson was forced to complete his paper without the thighbone on his 1797 journey to Philadelphia, during which he carried the fossils with him.

A matter of fate or luck however led Jefferson to reconsider his conclusions sometime after his arrival. He realized that his classification of the fossils as part of the cat family was probably wrong, when he came across an engraving of a strikingly similar fossilized skeleton in an issue of London’s Monthly Magazine. The skeleton was identified as a relative of the sloth and so Jefferson quickly revised his paper on the day of his presentation to the American Philosophical Society, deleting all references to a cat family connection.

In 1804 Jefferson was credited as the discoverer of the Megalonyx genus, an animal that is indeed related to the sloth family, and in 1822 the French naturalist Anselme Desmarest gave the extinct animal its formal name: Magalonyx jeffersonii. Jefferson’s ground sloth lived 150,000 to 10,000 years ago and is now the official state fossil of West Virginia.

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This illustration of the extinct Caribbean monk seal was done by artist Peter Schouten.

A newly released study focusing on an extinct species, the Caribbean monk seal (Monachus tropicalis), has revealed just how evolutionarily unique its only two living relatives, the endangered Mediterranean and Hawaiian monk seals, truly are.

DNA analysis and skull comparisons by Smithsonian scientists and colleagues show the Caribbean and Hawaiian species together represent a new genus, long isolated from other seals. As a result, the Mediterranean and Hawaiian monk seals are the last and only living species of long separated branches on the seal family tree.

This is the first new genus recognized among modern pinnipeds (seals, sea lions, and walruses) in more than 140 years. The team’s findings are published in the scientific journal ZooKeys.

First reported by Christopher Columbus in 1494, the Caribbean monk seal once ranged throughout the Caribbean with an estimated population in the hundreds of thousands. Unrestricted hunting led to its eventual extinction by the 1950s. Monk seals, as a group, are unusual among seals in being adapted for life in warm water.

With the Caribbean species now extinct, the Hawaiian monk seal is the last surviving species of the genus Neomonachus, as the Mediterranean species is in its genus, Monachus. Only about 1,200 Hawaiian seals are left and the Mediterranean monk seal is even more rare with a population of  fewer than 600.

A Hawaiian monk seal and her pup. (Photo by Tom Elliot)

Specimens of the Caribbean monk seal are today found only in museum collections, the largest sample residing in the Smithsonian’s National Museum of Natural History. Studying the remains of these seals and their relatives led to this new discovery by several Smithsonian scientists, including Kris Helgen, curator of mammals; Graham Slater, Peter Buck post doctoral fellow;, Charley Potter, collection manager of Marine Mammals; and their colleagues..

“The DNA extracted from the century-old monk seal skins in the museum’s collection showed us that the Caribbean species was more closely related to the Hawaiian rather than the Mediterranean monk seal,” Helgen explains.

The genetic work was conducted in collaboration with scientists at the Leibniz Institute of Zoo and Wildlife Research in Germany and Fordham University in New York. Major genetic distinctions, along with the morphological differences Slater found between the Mediterranean species and the two New World species (Caribbean and Hawaiian), led the team to classify the Caribbean and Hawaiian monk seals in the a newly named genus, Neomonachus.

Diorama with a Mediterranean monk seal at the The Natural History Museum in Milan, Italy. (Photo: Giovanni Dall’Orto)

“We occasionally identify new species of larger mammals, like the olinguito we announced last year,” Slater says. “But to be able to name a new genus, and a seal genus at that, is incredibly rare and a great honor.”

Beyond the reclassification, the study has also shed light on how the evolution of the Caribbean and Hawaiian monk seals directly relates to a major geological event.

“The Caribbean and Hawaiian monk seals split into distinct species around 3 to 4 million years ago,” Slater explains. “This is about the same time the Panamanian Isthmus, the bridge between North and South America, closed off the connection between the Atlantic and Pacific Oceans, which would have naturally separated the two.”

With both species being listed as “critically endangered” by the International Union for Conservation of Nature, this discovery has real implications for the conservation of both species.

“This work has really upped the stakes in terms of trying to conserve these species,” says Charles Littnan, lead scientist for the NOAA Fisheries Hawaiian Monk Seal Research Program. “There are multiple groups working across the planet trying to save the Mediterranean and Hawaiian monk seals. We were hoping to save both species, or at least one of them, to maintain some legacy of the Monachus genus on the planet. But now, as a result of this paper, we now know they are different lineages, and are both too valuable to lose.”

Paper link: “Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology,” ZooKeys 409 (2014): 1-33, by Dirk-Martin Scheel, Graham Slater, Sergios-Orestis Kolokotronis, Charles Potter, David Rotstein, Kyriakos Tsangaras, Alex Greenwood and Kristofer M. Helgen.

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Termites and ants are not something you’re likely to pour into a cereal bowl for breakfast or munch with toast and tea, but your ancient ancestors almost certainly enjoyed eating them—alive! In fact, new research on the insect-eating behavior of chimpanzees reveals termites and ants are a highly nutritious food that is easily accessible to chimps in the bush. Faced with the same conditions millions of years earlier, researchers say, our hominid ancestors may have gobbled down insects to ease the cravings of an empty stomach.

As a Ph.D. student, Robert O’Malley spent months following a chimpanzee troop in Gombe National Park, Tanzania, recording the insects that they ate and collecting samples to be analyzed at the National Zoo’s Nutrition Laboratory, a part of the Smithsonian Conservation Biology Institute (SCBI). His findings further our understanding of chimpanzee diets and also give us strong insights into the diet of early hominids.

Dr. Goodall, I presume?

Made famous by the research of Dr. Jane Goodall, the Gombe chimpanzees have been studied by scientists for more than 50 years, spanning several chimp generations. By watching these chimpanzee families Goodall not only noted that they often eat insects but also made the discovery that they use tools to reach them.

“Chimpanzees go ‘fishing’ for termites and ants by using sticks or leaves to prod insect mounds. Termite soldiers attack the probe and the chimps pull it out and eat them,” says O’Malley, who works at the Center for the Advanced Study of Hominid Paleobiology at George Washington University. “Many studies have focused on the use of tools by chimpanzees to eat insects but very little has been done on the nutritional benefit of this behavior. We had so many questions: How do they decide which insects to eat…perhaps by observing others in their group? Just how many insects are they eating? Do they eat insects only because they taste good, or is there any real nutritional benefit that has made this a part of their feeding behavior?”

To answer these questions O’Malley spent months constantly following the troop through the Tanzanian jungle.

“My research was done in the rainy season, which can be quite unpleasant due to the occasional torrential rain. I spent many hours each day going up and down these huge hills following the chimps and trying to stay with them,” O’Malley says. “If they were doing something like eating termites or ants then I would video record it. This would allow me to score, hopefully with great accuracy, the volume and type of insects they were eating. I also collected samples of the insects they ate to test back at the laboratory.”

Robert O’Malley videotapes a chimpanzee troop in Gombe National Park, Tanzania, “fishing” for termites on a termite mound. (Photo courtesy Robert O’Malley)

Small, delicious and definitely nutritious

Back at the National Zoo’s Nutrition Laboratory, O’Malley and his co-author SCBI biologist Michael Power ground the insects up to measure their nutritional content. Although the different insects the chimpanzees ate differed in nutritional composition, their favorites were routinely those with the greatest nutritional return.

“Chimpanzees prefer eusocial insects like termites and it was these insects that most consistently met our estimates for recommended dietary intake of minerals, and non-trivial amounts of fat and protein,” O’Malley explains. “The termite soldiers that they eat supply them with several dietary minerals while the winged “alate” termite caste, which fly out to start new nests, are very high in fat—about 25 percent, which is extraordinary for an insect.”

Robert O’Malley, right, and colleague collect insects in the jungle. These specimens were later taken to a laboratory to measure their nutritional value as a chimpanzee food source. (Photo courtesy Robert O’Malley)

Though most of their diet is ripe fruit, chimpanzees are omnivores like humans, not only eating insects but also meat, hunting animals such as monkeys and piglets. So why would chimpanzees spend so much time, more than four hours on some days, collecting and eating such a tiny food when they could be hunting?

“Going after insects is much safer, especially if mothers have their young with them,” Power explains. “The females are a lot more patient and often more skilled at termite fishing than the males. Males often don’t stay around if they don’t quickly get a good return. The females, however, stick it out, maybe because they realize they have a guaranteed source of food.” 

Could our ancestors have spent time eating termites?

Several million years ago, our human ancestors lived in similar sub-Saharan habitats in Africa. These extinct hominids were approximately the same size as a chimpanzee and quite possibly used similar tools and strategies to harvest insects.

A chimpanzee troop in Gombe National Park, Tanzania, dining on termites that they pull from the mound using long sticks. (Photo by Robert O’Malley)

“Chimpanzees represent a useful referential model which we use to make inferences about the diet and behavior of extinct hominids,” O’Malley explains. “We will never be able to go back and observe what our ancestors were doing directly, but by studying chimpanzees we can infer how an omnivorous ape would deal with similar challenges. We can also look to the archeological records for supporting evidence for what we see in the field.”

Archaeologists Lucinda Backwell from University of the Witwatersrand, South Africa and Francesco d’Errico from du Centre National de la Recherche Scientifique, France, have found evidence, which suggests that bones were used as digging tools in termite mound soil by hominids in South Africa between 1.8 and 1 million years ago. Furthermore, all the insect genera that O’Malley witnessed the apes eating in Gombe are likely to have been available to hominids living in sub-Saharan East Africa for most of the last several million years

“We humans use tools, and many cultures around the world today still eat insects,” O’Malley says. “One of the implications of this study is that we show chimpanzees, using very simple technology, can use termites and ants as a viable source of fat, high-quality protein and minerals. This was also probably true for extinct hominids.”

Journal Link: “The energetic and nutritional yields from insectivory for Kasekela chimpanzees,” by Robert C. O’Malley and Michael L. Power, Journal of Human Evolution, April 2014.

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On April 15 the National Museum of Natural History took delivery of a nearly complete Tyrannosaurus rex skeleton. Called the Nation’s T. rex, it will be the centerpiece of the museum’s new 31,000-square-foot dinosaur and fossil hall, which is slated to open in 2019. The current dinosaur and fossil hall will close to the public at the end of the day April 27 in preparation for the largest, most extensive exhibition renovation in the museum’s history.

To celebrate the legacy of dinosaurs in the Nation’s capital, a variety of programs will be offered for the remainder of the month of April. The museum also plans to launch three interim dinosaur-focused exhibitions this year that will give visitors a chance to immerse themselves in the ancient world of dinosaurs and cutting-edge paleontological research. The museum is planning additional exhibitions and programs for 2015–2019.

Tyrannosaurus rex Osborn (Cast) Known as the “Wankel T. rex,” the rare fossil was found in 1988 by Kathy Wankel, a rancher from Angela, Mont., on federal land near the Fort Peck Reservoir in eastern Montana.

“Tyrannosaurus rex is truly the king of dinosaurs,” said Kirk Johnson, the Sant Director of the National Museum of Natural History. “We could not be more excited to welcome the Nation’sT. rex to Washington so it can be enjoyed by our 8 million visitors a year and serve as a gateway to the vast world of scientific discovery.”

The Nation’s T. rex

The new T. rex, on loan for 50 years from the U.S. Army Corps of Engineers, was discovered on federal land in 1988 by Montana rancher Kathy Wankel. A team of paleontologists from the Museum of the Rockies in Bozeman, Mont., led by paleontologist Jack Horner, excavated the fossil from 1989 to 1990. It was then transferred to the Museum of the Rockies by the Corps for preparation and housing. It is one of the largest and most complete T. rex specimens ever discovered, with 80–85 percent of the skeleton recovered. The Nation’s T. rex arrived April 16 via FedEx.

On April 15, 2014, the National Museum of Natural History welcomes the Nation’s T. rex to the Smithsonian Institution. The Tyrannosaurus rex specimen, on loan from the U.S. Army Corps of Engineers, is the Museum’s first nearly-complete T. rex skeleton, and will be the centerpiece of the Museum’s renovated fossil hall slated to open in 2019. (From left) Kirk Johnson Ph.D., Sant Director, National Museum of Natural History, Smithsonian Institution; Kathy and Tom Wankel, the individuals who discovered the T.rex in Montana in 1988; and Lt. Gen. Thomas P. Bostick, Chief of Engineers and Commanding General, United States Army Corps of Engineers. (Photo by James Di Loreto / Smithsonian Institution)

The New Dinosaur and Fossil Hall

The new hall will be named in recognition of David H. Koch, a philanthropist and executive vice president of Koch Industries Inc. His gift—$35 million of the exhibition’s total projected cost of $48 million—is the largest single gift in the history of the Natural History Museum. The exhibition will showcase impressive specimens from the museum’s unrivaled collection of 46 million fossils; structured as a journey through time, it will start from the formation of Earth and the beginnings of life through 10 geologic time periods and two major extinctions.

As the renovation progresses, the museum will update visitors about major milestones in the immense makeover through various channels, including social media and Q?rius, the museum’s educational learning lab, and temporary exhibits around the building.

Rex Room

Dinosaurs will continue to be on view at the museum through three new interim exhibitions and additional exhibitions and programs during the five-year renovation period. The 1,830-square-foot Rex Room, opening April 15, will offer visitors the unique opportunity to see staff members unpack, catalog, photograph and 3-D scan the 66-million-year-old bones of the Nation’s T. rex. Visitors will also have the rare chance to see a line-up of skulls from four different species of tyrannosaur specimens loaned by the Bureau of Land Management.

Augmented Reality Dinosaurs

The “Augmented Reality Dinosaurs” exhibition opens in late May on the museum’s second floor. Appshaker, a London-based digital company, created a project that allows museum goers to interact “virtually” with dinosaurs such as T. rex, Triceratopsand Troodon, in a setting that represents their ancient natural habitat.

Last American Dinosaurs

“The Last American Dinosaurs: Discovering a Lost World,” a 5,400-square-foot exhibition, opens Nov. 25 and tells the story of the final days of dinosaurs found in the Hell Creek Formation of North Dakota. Visitors can explore this world of 66 million years ago, before an enormous and sudden asteroid impact drastically altered the flora and fauna forever. Triceratops, T.rex and many other fossils large and small will help visitors appreciate how the planet’s ecosystems respond to drastic environmental changes. The exhibition will also feature a special area on fossilization and fossil finding as well as the museum’s popular FossiLab, a working laboratory staffed by experts and volunteers that gives visitors a personal glimpse into fossil preparation and the day-by-day process of paleontological discovery.

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Finding a fossil is the first step, recognizing it for what it truly is, is the real challenge.

While closely studying three fossil skeletons from museum collections a team of scientists from the Smithsonian’s National Museum of Natural History, the Carnegie Museum of Natural History and the University of Utah, reached that “aha!” moment with the realization they had discovered a new bird-like dinosaur previously unknown to science. They named it Anzu wyliei, in part after a feathered demon from ancient Mesopotamian mythology.

An illustration of Anzu wyliei shows its long, slender ostrich-like neck and hind legs; unlike an ostrich, A. wyliei also had forelimbs that were tipped with large, sharp claws. (Illustration courtesy Bob Walters)

The discovery represents the first North American example of a species belonging to Oviraptorosauria, a group of dinosaurs mostly known from fossils found in Central and East Asia. “For almost one hundred years, the presence of oviraptorosaurs in North America was known only from a few bits of skeleton. The details of their appearance and biology remained a mystery,” says Dr. Hans-Dieter Sues, curator of Vertebrate Paleontology at the National Museum of Natural History. “With the discovery of A. wyliei, we finally have the fossil evidence to show what this species looked like and how it is related to other dinosaurs.”

In addition to Sues, the study’s authors are Matthew Lamanna of the Carnegie Museum of Natural History, Emma Schachner of the University of Utah and Tyler Lyson of the National Museum of Natural History.

No BBQ is large enough for this discovery

Resembling a cross between a modern emu and a reptile, the new dinosaur A. wyliei is a striking find. Originally collected in the early 1990s, the bones of the newly described dinosaur were found in the Upper Cretaceous Hell Creek Formation in North and South Dakota, inspiring scientists to nickname it “The Chicken from Hell.”

Smithsonian scientists, Hans-Dieter Sues (right) and Tyler Lyson (left), examine a reconstructed Anzu wyliei skull. (Photo by Brittany Hance)

Described for the first time today in the scientific journal PLOS ONE, A. wyliei stood 5 feet tall at the hip and was roughly 11 feet long, resembling a large flightless bird with feathers on its arms and on its extraordinarily long tail. It had a toothless beak and a tall crest on top of its skull, similar to an Australian cassowary. Its neck and hind legs were long and slender, like that of an ostrich, but here the bird similarities end. Its forelimbs were tipped with large, sharp claws.

Alive during the Cretaceous Period from about 68 to 66 million years ago, A. wyliei would have roamed at the same time as the Tyrannosaurus rex and triceratops.  A. wyliei is likely to have suffered the same fate as its dinosaur contemporaries, dying out in the great extinction event when an asteroid hit the earth.

“While we are certain that this species had feathers like its Asian relatives, we are pretty sure that modern birds did not evolve from this group,” Sues points out. “Unfortunately there is no evidence of these creatures after the asteroid impact 66 million years ago, however other feathered dinosaurs such as the dromaeosaurids lived on. These include the well-known velociraptors which we believe are the ancestors of our birds.”

Bones can give an insight to a way of life

Before its unfortunate demise A. wyliei would most likely have been found wandering the humid floodplains of North America. “The three skeletons were found in mudstone rock that was deposited on ancient floodplains,” Sues says. “This differs greatly from their Asian oviraptorid cousins, which are found in rocks deposited under arid to semi-arid conditions.”

Cassowaries are a large flightless birds from tropical forests of New Guinea and northeastern Australia. (Photo by Michal Zacharzewski)

While much of the new dinosaur’s way of life remains a mystery, the structure of its skull has given scientists some clues as to its preferred food and mode of social interaction. They believe the jaw structure of A. wyliei suggests it was an omnivore, able to eat meat and plants. The function of the bony crest on top of its skull is less clear but has alluded to more flamboyant theories of its lifestyle.

“The crest on the skull is very large and made of paper-thin bone, so it was not able to take much stress,” Sues says. “All oviraptosaurs have this crest but it is certainly the largest in A. wyliei. The most likely function is for display, showing off to members of your own species. The Australian cassowary has a similar crest which is thought to be used to attract mates, so it is possible that A. wyliei could have used its crest in a similar fashion.”

Analyses of the A. wyliei fossils have not only given insight into the life of this new species but also the amazingly diverse family to which it belongs, the Caenagnathidae. This group included species that were as small as turkeys and as large as A. wyliei.

As part of their study the research team confirmed previous suggestions that Gigantoraptor, the largest known oviraptorosaur at 1.5 tons, is an Asian member of Caenagnathidae. “Although we expected to find these dinosaurs in both Asia and North America as the land masses were connected at one time, we now know North American oviraptorosaurs were more closely related to each other than they were to most of their Asian cousins,” Sues says.

Come see the dinosaurs that roamed with A. wyliei

The National Museum of Natural History will showcase dinosaurs and other fossils from the world in which A. wyliei lived as part of its upcoming exhibition, “The Last American Dinosaurs: Discovering a Lost World,” which opens Nov. 25. The exhibition will feature specimens from 68 to 66 million-year-old rock formations, such as Tyrannosaurus rex and triceratops.

“The Hell Creek Formation has been intensely studied by paleontologists for more than a hundred years, and we’re still finding phenomenal specimens,” said Kirk Johnson, Sant Director of the National Museum of Natural History. “We are excited and honored to continue sharing our collection of fossil discoveries with our visitors for years to come.”

#AnzuDino

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It has all the hallmarks of a paleontological crime scene: a massive graveyard along a remote desert highway containing the fossil bones of at least 40 dead whales and a slew of other marine victims. Discovered in 2010 in the Atacama Desert of Chile, this mysterious assemblage of bones baffled scientists trying to piece together the chain of events that led to its creation during the Miocene. Known locally as Cerro Ballena, or Whale Hill, it is the densest site for individual fossil whales and other extinct marine mammals ever found.

Now the mystery is solved: poisoning resulting in sudden death at sea. The culprit: common ocean algae. Blooming in profusion some 6 to 9 million years ago, the algae produced a deadly neurotoxin that was either ingested or inhaled by the animals causing organ failure and rapid death. Scientists believe the algae blooms were triggered by iron-rich runoff from the Andes Mountains. A scientific verdict on these deaths is handed down in a paper released today (Tuesday, Feb. 25) in the Proceedings of the Royal Society B.

Clues found in the graves

One clue to the cause of the calamity was that many of the whale skeletons are lying belly-up. “Like today’s humpback and blue whales, these prehistoric whales had a big throat pouch,” says Nicholas Pyenson of the Smithsonian’s National Museum of Natural History, lead author of the study. When they die and decompose the throat pouch fills with gas and “acts like a flotation device, it’s like a hot air balloon coming off their throat,” Pyenson explains. This belly-up position of the skeletons reveals the whales died out at sea and did not strand themselves upright on the shore.

The remarkably complete condition of many of the skeletons also reveals their upside-down bodies washed ashore quickly, soon after the animals died and before their remains could be scavenged and scattered by large ocean predators like sharks. “These big hunks of meat stranded on a tidal flat, yet there were no terrestrial predators like a bear, nothing really larger than a dog, that could dismember the carcasses and carry the bones away,” Pyenson says. In time the carcasses became bare bones that were covered over with sand.

Chilean and Smithsonian paleontologists study several fossil whale skeletons at Cerro Ballena, next to the Pan-American Highway in the Atacama Region of Chile, 2011. (Photo by Adam Metallo)

Fossil algae mats found on the skeletons are another important indicator that algae blooms killed these animals. The fossil algae mats—produced when algae blooms in extreme profusion—are an orange color and have high iron content, Pyenson says. “In the modern world, dissolved iron promotes harmful algae blooms and the Andes are very iron-rich. So we argue that the mountains east of the site are the ultimate source of what’s powering these ancient blooms.”

A third important clue to cause of death is that such an eclectic assemblage of animals was buried at the site, Pyenson says. Although large baleen whales dominate the Cerro Ballena graveyard, ten different kinds of marine vertebrates are found there, including several whale species, marlins, two different species of seal, a walrus-like whale and an aquatic sloth. This indicates a large, indiscriminate event that took the lives of many creatures simultaneously, not just a virus, say, or other illness that killed only whales.

Not the first time the algae has killed

As it turns out, the evidence also exposes the algae as a repeat offender. Possibly the most important clue pointing to algae as the culprit, is that four different assemblages of fossil bones are found on four geologic levels in the Cerro Ballena deposit. This means this catastrophic death event occurred not once, but at least four different times in the same spot during a period of 10,000 to 16,000 years.

“The condition and arrangement of the bones, the presence of algal mats on some fossils, and the fact that there are multiple species of marine animals at the site, all point to killer algae as really the only plausible explanation,” Pyenson says. “In today’s world harmful algae blooms happen all the time. This is the first time we can pin it down in the fossil record for marine mammals.”

Chilean and Smithsonian paleontologists study several fossil whale skeletons at Cerro Ballena, next to the Pan-American Highway in the Atacama Region of Chile, 2011. (Photo by Adam Metallo)

What intrigues Pyenson about the Cerro Ballena site is that it offers such a clear window into the marine ecosystems and marine food webs of the Miocene. “I’m amazed at how comprehensive a snapshot it is,” he says. “We have a little bit of the familiar—baleen whales—and a little bit of the exotic—an extinct aquatic sloth and an extinct walrus whale. Yet in 240 meters of road cut we can sample fossil marine mammals that pretty much represents everything that we know of living in the ocean in South America at that time. That is what is compelling to me.”

The Cerro Ballena site also reveals just how full the oceans once were of whales, with some regions possibly even experiencing super-aggregations of whales, Pyenson says. “We don’t see baleen whale strandings like Cerro Ballena today. The issue is that today’s world has a shifted baseline because we nearly killed off all the baleen whales. They didn’t go extinct but we reduced their abundances by upwards of 95 percent. What was normal on Earth for hundreds and even thousands of years is no longer normal. So we are living in a very altered world today where baleen whales are not nearly as abundant as they used to be.”

Above: 3D digitization captured essential data about the arrangement and condition of the skeletons at Cerro Ballena before they were safely removed and deposited at the Museo Paleontologico de Caldera, a local natural history museum. 

In addition, Pyenson says, the enormous wealth of fossils found at Cerro Ballena probably represent only a fraction of what is buried there. In fact, Pyenson adds, Cerro Ballena tells us that whale assemblages may actually be a lot more common in the fossil record than recognized and scientists might look elsewhere in the world in similar types of continental settings for other such assemblages of bones.–John Barrat

#whalegraveyard

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After years of sleuthing for clues about where and when pantherine felids (“big cats”) originated, a Smithsonian scientist and an international team of researchers are one step closer to understanding the evolutionary history of these species. A fossil recently found in the Zanda Basin in Tibet included remains of Pantera blytheae, a new species of big cat that is most closely related to the modern day snow leopard. The skull of P. blytheae is the oldest big cat fossil found to date, and fills a significant gap in the fossil record. It indicates that ancient big cats lived nearly 6 million years ago, 2 million years earlier than previously thought, and sheds light on their geographic origins in Asia. Scientists plan to build on this research by studying how big cats evolved and adapted to changes in their environment over time to help inform modern day big cat conservation efforts. The research is published in the Jan. 7 issue of Proceedings of the Royal Society B: Biological Sciences.

A life reconstruction of the skull of P. blytheae, the oldest known pantherine cat. Scientists believe this ancient species of big cat is most closely related to the modern day snow leopard (Artwork by Mauricio Antón)

Graham Slater, a Peter Buck post-doctoral fellow at the Smithsonian’s National Museum of Natural History, examined the remains of P. blytheae after its excavation, and helped confirm its status as a new species by conducting morphological and DNA analyses of the skull.

“P. blytheae is a missing link we’ve been searching for in the timeline of big cat evolution,” said Slater. “Scientists are now closer to understanding the evolutionary origin of big cats and are gathering data about their habitat. The hope is that we can apply our knowledge of how P. blytheae adapted to environmental changes millions of years ago to predict the sustainability of snow leopard populations in existence today.”

Ancient cat fossils are rare, making the nearly complete P. blytheae skull an incredibly valuable specimen. Before this discovery, the oldest known fossils of big cats indicated that they first appeared about 3.8 million years ago in Africa. However, DNA comparisons of modern species suggested that big cats evolved at least 6 million years ago in Asia. For the past decade, scientists have been searching for a way to explain these discrepancies. Thanks to the discovery of P. blytheae, researchers now have a critical piece of evolutionary evidence that reconciles the existing fossil and molecular data for big cats and helps tell the story of their evolution.

While the P. blytheae skull is helping scientists better understand when big cats first appeared, the search for even older fossils continues. Phylogenetic evidence suggests that the big cats subfamily, Pantherinae (e.g., lions, tigers, leopards), shared a common ancestor with their evolutionary cousins, Felinae (e.g., cougars, cheetahs, domestic cats), until about 10.8 million years ago when the two lines diverged. The research team plans to search for evidence of this ancestor as well as new big cat species in the Miocene rocks of central Asia, while continuing to add to their collection of P. blytheaespecimens.

The scientists also intend to study the skull in the context of its surrounding fossils, a diverse collection of ice age cats and other species such as Tibetan antelope and blue sheep. The dependency that existed between ancient snow leopards and blue sheep millions of years ago is observed in modern populations of both species, demonstrating the importance of prey populations in long-term carnivore survival. By investigating how P. blytheae adapted to changes in prey availability and environmental conditions, scientists can develop conservation strategies to protect modern day big cat species facing similar threats due to habitat degradation and climate change.

The top of the P. blytheae fossil skull. This specimen revealed that ancient big cats lived nearly 6 million years ago, 2 million years earlier than previously thought. (Photo: Gary T. Takeuchi)

Slater worked with a team of scientists from around the world to confirm the new big cat discovery. These researchers include Jack Tseng, a postdoctoral fellow at the American Museum of Natural History who led the excavation team, as well as five other scientists from academic and museum institutions in the United States, Canada and China.

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