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Posts tagged ‘mammals’

Global warming and declining mammal diversity: new research in Nature

Pleistocene survivor, the deer mouse.  Photo by Glenn and Martha Vargas © California Academy of Sciences

Pleistocene survivor, the deer mouse. Photo by Glenn and Martha Vargas © California Academy of Sciences

Popular images of Ice Age California tend to feature enormous, extinct mammals like mammoths and saber-toothed cats.  By contrast, new research published in Nature examines populations of small mammals that survived through the end of the Ice Age and how they were affected by the climate change.

The research team of Jessica Blois (formerly at Stanford, now at University of Wisconsin, Madison), Elizabeth Hadly (formerly of UCMP, now at Stanford) and Jenny McGuire (UCMP) studied fossilized woodrat nests collected from Samwell Cave in Northern California.  Woodrats carry scat and regurgitated pellets produced by carnivores back to their nests.  These collections are filled with undigested small mammal bones, making fossilized woodrat nests treasure troves for paleontologists.

Comparing fossil data to modern small mammal populations in the same region revealed a big decrease in diversity during a period of global warming at the end of the Pleistocene Epoch.  There was a decrease in both species richness (number of different species) and evenness (relative dominance of species within a community).  A few species disappeared from the area entirely.  Some species remain in the area but as a much smaller proportion of the overall small mammal community.  And the main species to increase in relative abundance was the deer mouse — an animal that can tolerate a wide variety of habitats and climates.

Research of historic periods of global warming improves our understanding of how modern, man-made global warming will affect life on Earth.  Read more about this research:

Marine vertebrate paleontology in Half Moon Bay

Paleontology along California's coastline

Paleontology along California's coastline. A) Fieldwork on the coast often involves climbing up ledges to get access to just one more meter of outcrop. B) A fossil tooth of the great white shark, Carcharodon carcharias. C) A freshly collected tympanic bulla of an extinct porpoise (Phocoenidae).

This week, we welcome guest blogger Robert Boessenecker. Bobby has been interested in paleontology since he was a kid. He grew up in the Bay Area; when he found Miocene shark teeth in the Santa Cruz Mountains, he was hooked.  He first got involved with the UCMP when he was a high school freshman — he visited the museum with his dad, to interview UCMP Assistant Director Mark Goodwin for a school project. Bobby is now getting a Masters' degree at Montana State University. He studies the taphonomy and preservation of marine vertebrate fossils in the Mio-Pliocene Purisima Formation of Central California.

After the completion of my first year of college, I was relaxing during my family's annual vacation at Lake Tahoe. While at the beach I received a phone call from my uncle; a surfing buddy of his had discovered a bunch of fossil bones somewhere near Half Moon Bay. I was excited, primarily because few discoveries of fossil vertebrates had been made along the San Mateo County coastline. I knew that much of the county's shoreline was made of the Purisima Formation, a rock unit I was familiar with from collecting fossils in the Santa Cruz area.

The Purisima Formation is late Miocene and Pliocene in age (7-2.5 Mya). In the Santa Cruz area, fossils of sharks, rays, skates, bony fish, sea birds, walruses, fur seals, dolphins, belugas, baleen whales, and sea cows had been discovered. With such a diverse fossil assemblage, I knew there was serious potential for discovery at this new spot in Half Moon Bay.

A day or two after we returned from Tahoe, my friend Tim Palladino and I followed directions to the locality, and sure enough, it was all Purisima Formation. When we arrived, the exact spot the surfer pointed out was up along a two foot wide ledge overhanging a thirty foot drop to the beach; neither of us were crazy enough to try climbing up there, and we decided to explore elsewhere. Shortly thereafter, we discovered several bonebeds with abundant bones and invertebrate shells preserved. Because the locality was on government-owned land, collecting without a permit was illegal.

After returning to Montana for my second year of college, I applied for (and eventually received) a permit, so that I could return to the locality and establish a collection. In summer 2005, I returned, and discovered a fossil skull of a baleen whale. The excavation took four days and half a dozen volunteers, but eventually the skull was excavated and wrapped in a plaster jacket for safe transport back to Montana. After the plaster jacket was removed that fall, I found that the skull was also encased in a concretion — the sandstone closer to the middle of the skull had been cemented with calcium carbonate, the same mineral in limestone. Needless to say, preparation took four and a half years, and was only finished in March 2010.

In 2006 I returned to the locality. We made two major finds that summer: the nearly complete skull of a fossil porpoise, and a complete lower jaw of the "'dwarf"' baleen whale Herpetocetus. In addition to these finds, by the end of 2006 I had collected several shark teeth (including those of great white sharks, basking sharks, angel sharks, a mako shark, and even a sawshark), fish bones, the humerus of an extinct flightless auk (Mancalla diegensis), bones and teeth of a walrus and a fur seal, and multiple ear bones of porpoises and several baleen whales (Herpetocetus, a right whale, and a rorqual whale). All of this fossil material is currently under curation for UCMP collections. UCMP has more fossil material from the Purisima Formation than any other repository, and now it is the recipient of an entirely new fossil assemblage from the Purisima. All in all, the collection includes several hundred specimens that represent 22 different species of marine vertebrates.

To learn more about Bobby's research, check out his blog, The Coastal Paleontologist.

Bobby Boessenecker in the field 1 Bobby Boessenecker in the field 2 Purisima Fossils Paleontology along California's coastline

The game of prehistoric life

EOP-cover

Evolve or Perish is a new board game – not from the makers of Monopoly, but from ETE, the Evolution of the Terrestrial Ecosystems Program, at the Smithsonian National Museum of Natural History. UCMP Faculty Curators Cindy Looy and Ivo Duijnstee designed the game in collaboration with illustrator Hannah Bonner. Hannah is well-known for her cartoon paleobooks When Bugs Were Big and When Fish Got Feet. The three enjoy collaborating -- Hannah created the logo for Cindy's lab's web site, and she is currently consulting with her on a regular basis for her next book.

Evolve or Perish is similar to Chutes and Ladders. It begins 635 million years ago, with the first multi-celled organisms. Each square on the board represents 10 million years. On the path to the present, numerous fates await you: slip on an early animal and go back one square; land on the Cambrian Explosion and jump ahead; land on the largest extinction event the world has ever known and go back nine spaces. The game is populated by cute animals (the first four-legged animal wears a party hat!) and strange-looking plants (like Lycopods from the coal swamps of the Carboniferous). All of the beautifully drawn creatures represent real plants and animals, known from the fossil record; a taxa list helps you learn your Oxynoticeras from your Omeisaurus. As you move your game piece from the past to the present, Earth's major milestones appear along the way – you'll pass meteors, millipedes, and the rise of giant mammals. The first player to make it to the present day wins the game – but experiences a gross revelation about how some of Earth's first inhabitants inhabit us humans, too.

The game can be downloaded for free here.

Fossils found fortuitously

Whale Excavation INot all fossils are discovered by paleontologists combing the earth on special expeditions. Many fossils are found by accident — particularly during construction projects. Impressive fossils, like whales, mammoths, and sloths, have been found while digging foundations for buildings, leveling land for highways, and excavating subway tunnels. This spring, the UCMP blog will take you on a tour of Bay Area construction sites, past and present, to show you some of the fossils underfoot in the region.

This week, Dave Haasl, a former Museum Scientist at the UCMP, tells us about his work with PaleoResource Consultants, a consulting firm that performs what is known as mitigation paleontology. If fossils are found on public lands during construction, the law requires that they be preserved. The fossils need to be excavated quickly, so that construction can carry on. And, the fossils need to be excavated by trained paleontologists, so they are properly preserved for future scientific study. This is a job for mitigation paleontologists! As Dave explains, "we need to mitigate the impact [of construction] to scientifically important resources. This includes fossils, as well as archaeological specimens."

There are two parts to mitigation paleontology. First, the paleontologists do pre-construction field surveys. "We look at the stratigraphy of the area, and plot the potential fossil localities," says Dave. Then, when those areas are dug up, workers know to be on the lookout for fossils. The second part of paleo mitigation is monitoring, which occurs throughout a construction project. Construction workers may not recognize fossils when they come across them, so it's important to have a trained paleontologist on site. If fossils are found, the monitors halt construction and quickly excavate the fossils. They call in a network of paleontologists, and typically they are able to excavate the fossils within a few days.

Recently, two marine mammal skeletons, a whale and a dolphin, were found during the construction of a sea wall along the California coastline. Santa Cruz County is building a sea wall between Santa Cruz and Capitola, to protect the cliffs and buildings from large waves. However, the sea wall will block access to that section of the coastline, preventing any future paleontological exploration of the area. Paleontologists were asked to survey the area before the wall was built, to see if any fossils were present.

An amateur paleontologist had seen vertebrae protruding from the sandstone — these vertebrae belonged to a small whale that lived in the late Miocene, about 5 million years ago. PaleoResource Consultants excavated the specimen, wrapped it in plaster to protect it during transport, and brought it back to their offices in Auburn, California, where it is now being prepared.

A second skeleton, a dolphin, was found by Robert Boessenecker, a graduate student at Montana State University studying marine vertebrate fossils in California. The dolphin, now extinct, is also from the late Miocene, and is related to the Chinese river dolphin. "Marine mammals were much more diverse at that time," says Dave.

While Dave's career path as a paleo mitigation consultant may seem unusual, there is a real need for trained paleontologists in this field. "There is more paleo work in the West than paleontologists who can do it," he says. "Often, archaeologists do the work, because paleontologists are not available." And this work is important. As a result of big construction projects, fossil material is collected that otherwise would still be in the ground. These specimens are then used in scientific research. Says Dave, "This is our historic heritage. If it's destroyed or sealed off, we're losing something of potential scientific value. Yeah, we need roads, we need power plants. But we're going to try to preserve as much of our past as we can."

Learn more about fossils found during construction projects in upcoming blogs!

Whale Excavation I Whale Excavation II Whale Excavation III Whale Prep - edited

How many mammoths?

Jake Enk cuts off a piece of a mammoth toothA few weeks ago, the UCMP welcomed visitor Jake Enk, a graduate student from McMaster University in Hamilton, Ontario. Jake visited the UCMP to saw off chunks of fossil mammoth teeth. Yes, you read that right. He took a small saw, sterilized the blade with bleach, and sliced off a small piece of tooth. Even after tens of thousands of years, mammoth teeth still contain DNA. Jake will put a little piece of the tooth in a test tube, and use a series of chemicals to purify the mammoth DNA. He does this work at the McMaster Ancient DNA Centre. The DNA from the mammoths' teeth can tell us about mammoth population structure.

Here at the UCMP, Jake took samples from 35-40 mammoth teeth in our collections — including one of Lupé's teeth! The UCMP is just one stop on his museum tour — Jake visited the Illinois State Museum, the University of Nebraska State Museum, the Denver Museum of Nature and Science, and the Santa Barbara Museum of Natural History. Over the course of his trip, Jake collected samples from a total of about 175 animals. The mammoth teeth were collected all over the country — from Florida to Washington, and many localities in between. And, the animals lived at different times, over a period of about 200,000 years. By looking at the genetic diversity of the mammoths, through space and time, Jake will learn about variation in the size of the mammoth breeding population. This information can then be used to help answer ecological questions about mammoths.

Jake Enk's visit to the UCMP was funded in part by the Welles Fund. To learn how you can support research at the UCMP, click here.

Cutting off a piece of mammoth tooth Examining mammoth tooth sample

Lupé's story, part 2: Prototyping the mammoth exhibit

LupeSkullUCMP graduate student Kaitlin Maguire is working with the Children’s Discovery Museum in San Jose to develop a new exhibit about the life of Lupé, a mammoth fossil that was found in the nearby Guadalupe River.  This is the second in a series of blogs about Lupé and the new exhibit. Read Kaitlin’s first Lupé blog here.

Development of the Lupé Story Exhibition is moving along quickly as exhibit ideas come to life in prototyping labs, in which the development team at the Children’s Discovery Museum (CDM) sets up preliminary exhibits and opens them up to the public for feedback. Prototyping labs are an important aspect of developing an exhibition; the prototyping labs show how children interact with the exhibits and if the exhibits are successful in teaching the children something about Lupé, paleontology, and the process of science. Maureen Callanan, a professor at UC Santa Cruz, is also interested in the prototyping labs because it gives her and her graduate students a chance to study how children learn and interact with their parents and caregivers.  Maureen and her students then provide additional feedback to the CDM team from a cognitive psychology perspective. Preliminary exhibits in the first prototyping lab included bone puzzles, play dioramas of the Pleistocene, and sifting for fossils. The most popular exhibit in the first prototyping lab was the dig site where some children spent hours using wooden tools to dig out fossils of Pleistocene mammals.

In December, we all got the chance to meet Roger Castillo, the San Jose citizen who found the Lupé fossils as he was walking his puppy along the Guadalupe River. Hearing Roger tell his story about the discovery was inspirational. As a citizen scientist, he is invested in the health of the Guadalupe River and all it has to offer, including fossils. Growing up in San Jose, he has monitored the river his entire life. Specifically, he has looked at salmon populations in the river, changes in the level of the river, and erosion caused by the river.

Upon hearing Roger enthusiastically describe how he discovered the fossils, the CDM team decided to focus on recreating the “discovery moment” for children to experience at the museum. The next prototyping lab will contain exhibits designed to create an experience of discovery, excitement, and curiosity. Children will discover fossils on a riverbank, uncover them, and ask questions about the fossils much in the way Roger did. This prototyping lab will be open through the spring. A third prototyping lab will open in the fall and final production of the exhibition will start afterward leading up to the grand opening in the spring of 2011.

DigPit BonePuzzle Sifter

Fossils provide baseline for mammal diversity

Arctodus

Skull of a short-faced bear from northern California, an example of a species that went extinct after humans arrived in North America. Photo: Tony Barnosky

As more and more species go extinct, biologists wonder whether we are on the verge of the earth's sixth mass extinction.  A new study, by Marc Carrasco and Tony Barnosky of the UCMP and Russell Graham of Pennsylvania State University, uses the fossil record to examine mammal biodiversity in North America over the past 30 million years. Carrasco and his collaborators used data from two fossil databases, MioMap and Faunmap, to determine the baseline of mammal diversity before humans arrived in North America. Their results, published in the journal PLoS ONE, show that the arrival of humans 13 thousand years ago coincided with a 15 to 42% decline in mammal diversity. These data show that humans had a negative impact on mammals long before we factor in the effects of current industrialization and global climate change. Now that a pre-human baseline of North American mammal diversity has been established, we can compare current diversity to the continent's "normal" diversity level — an important comparison as we plan and evaluate conservation efforts in the future.

To learn more about Marc and Tony's study, read the paper on the journal PLoS ONE, the UC Berkeley News press release, and this article in the San Francisco Chronicle.

UCMP's Tony Barnosky in The Economist

Tony BarnoskyCheck out this week's issue of The Economist — it features the work of UCMP Faculty Curator Tony Barnosky. Tony looks at how climate change affects the ecology and distribution of mammals — in the distant past and in the future. The UCMP last blogged about Tony's work here.

Paleo Video: Kaitlin Maguire at the John Day Fossil Beds

Watch this video and join UCMP graduate student Kaitlin Maguire on a field trip to the John Day Fossil Beds National Monument! After visiting the park last spring, Kaitlin decided it's the perfect place to do her dissertation research.

"When you do a field project for paleontology, especially if you're looking for fossils, you never know what you're going to find — you never know if there's going to be enough data," says Kaitlin. But paleontologists from the UCMP and elsewhere have been studying the John Day Fossil Beds since the early 1900s. "There's a wealth of information to build on," she says. "I'm not just walking into the unknown."

A few fun facts about the John Day Fossil Beds:

  • The fossil beds, in eastern Oregon, were named for the John Day River, which runs through the area. The river got its name because of an incident that occurred at the river's mouth in 1812. A fur trapper named John Day was robbed by Native Americans — he was relieved of all of his belongings, including his clothes. Thereafter, the river was referred to as the John Day River.
  • Over 35,000 fossil specimens have been excavated from the John Day Fossil Beds. Many of those specimens were collected by UCMP paleontologists; the UCMP collections include thousands of fossils from John Day.
  • The John Day Fossil Beds National Monument has a paleontologist on staff, as do several other National Parks. Learn more about paleontology at the John Day on the Monument's website.

Lupé's story: A mammoth's journey from the ground to a museum

Lupe DigIn 2005, Roger Castillo found the fossilized bones of a juvenile mammoth in the Guadalupe River near San Jose. Roger was walking his dog along the river, which he did frequently as a volunteer for the Guadalupe-Coyote Resource Conservation District, when he saw the tusks of the mammoth's skull poking out of the soil along the riverbank. At the time he wasn't exactly sure what he was looking at but recognized their importance and contacted the UCMP. The fossilized mammoth has been named Lupé, after the Guadalupe River. The San Jose Children's Discovery Museum (CDM) will open a new exhibit in 2011 about Lupé's discovery. The exhibit will focus on how Lupé lived in the past and how scientists have pieced together evidence to understand her life.

I am a graduate student in the Department of Integrative Biology at UC Berkeley, and I have been working with the UCMP and CDM on the mammoth exhibit since February. At Berkeley, I study mammals from the past, their evolution, how they lived and their relationship with the environment. I got involved in this project because of my research interests. I mostly help the CDM team answer questions about mammoths and other Pleistocene mammals, as well as show them how paleontologists figure out the past from fossils and rocks. The CDM team visited the UCMP twice this spring to look at the collections and get a feel for what a typical day is like as a paleontologist. We also went on a field trip to the coast to look at fossils and learn about the local geology. I really enjoy sharing my experiences with the CDM team and love how excited everyone is to learn more about mammoths and paleontology.

But it's not just me teaching the CDM team! I have been learning quite a bit about how a children's museum designs exhibits for all ages. I attend CDM's brainstorming meetings and have been astonished by how creative a process it is. How do you design an exhibit that holds the attention of a 4 year old and her 12 year old sibling!? It's not easy, but with a lot of brainstorming and testing, the team comes up with fantastic exhibits.

Luckily, the project team also includes a group of researchers from UC Santa Cruz, led by Maureen Callanan. They focus on understanding how children learn science. One question the team has had during development of the exhibit is when do children understand the concept of time? Do they know that dinosaurs lived before mammoths? The UC Santa Cruz team is currently running experiments at the CDM to better understand what children will be able to learn from the exhibit. Their research has really helped guide the exhibit development.

I am very excited to be part of such a dynamic team of researchers and professionals. As we all learn from each other, great ideas unfold and the exhibit design moves forward. Over the next few months, I'll be updating you on our progress as we design and construct the mammoth exhibit. And I'll let you know when the exhibit opens in 2011!

UPDATE: Read Part 2 of Lupé's story!

Lupe Dig Lupe Lupe Map Lupe Locality