A Pleistocene pit-stop: the Barnosky lab excavates Natural Trap Cave, Wyoming

You might think that an 85-foot-deep hole where a bunch of horses, wolves, camels, elephants, and plenty of other animals accidentally plummeted to their death over tens of thousands of years would have enough red flags to make going into it yourself sound like a bad idea. But what if these unfortunate critters could tell you what their life was like and how they died? What if they could give you a warning about their death in a warming world after the last ice age and what it means for life in a warming world today? And, most importantly, what if you could fall and climb back out very slowly on a controlled rope system with an expert team of cavers and paleontologists? This past summer we decided to do just that: Barnosky lab members Eric Holt and Nick Spano with alums Susumu Tomiya and Jenny McGuire joined a crew led by Julie Meachen (Des Moines University) to descend into this “Natural Trap” Cave, excavate ice age mammal fossils, and help advance our understanding of how life responds to climate change, all without contributing any extra bones.

Natural Trap Cave is a 12-foot wide by 85-foot deep hole at the top of a hill in the Bighorn Mountains on the Wyoming side of the Montana border. The entrance to the cave is difficult to see coming down from the ridge of the hill behind it, so it’s not surprising that many Pleistocene ‘megafauna’ (animals bigger than 100 lb. or 45 kg)  accidentally fell to their demise here over tens of thousands of years ago. As they fell into Natural Trap Cave, their bones formed a well-stratified and mostly undisturbed pile that has become internationally renowned since the 1970s for its paleontological significance. The cave had been closed by the Bureau of Land Management (BLM) for over 20 years to protect the fossils from theft. However advances in ancient DNA research and growing interests in what Pleistocene extinctions could tell us for conservation prompted it to be reopened by Julie Meachen’s group for further research. This site is ~42 °F at ~98% relative humidity year-round, making it an ideal refrigerator for extracting 30,000 year-old genetic material. Geographically, it is located just south of a gap that existed between the Laurentide and Cordilleran ice sheets in central North America at the last glacial maximum (LGM) ~22,000 years ago. The ice-free corridor extended all the way up to Alaska and provides a unique opportunity to investigate continental migration dynamics, population genetics with ancient DNA, and climate-driven community changes.

This past summer, Eric and I (Nick Spano) drove 18 hours from Berkeley, CA to join a volunteer crew of paleontologists and cavers led by Julie Meachen at Natural Trap Cave in Wyoming. To enter the cave, each person needs to rappel down a rope hanging 85 feet down into the cave. Even if you claim to be unafraid of heights, the first descent is still slightly nerve-wracking. Stepping backwards off of the cave’s rim into a black pit with only a constellation of faint headlamps at the bottom can be a little unsettling. Plus, easing your grip on the rope here to let out slack takes a couple days to become comfortable with.

 

Descending

Eric Holt descending down a ladder towards the ‘edge of no return’.

Once you start the descent through increasingly colder temperatures, a council of packrat (Neotoma) middens along an inner rim welcomes you to the cave. After the initial shock of dangling passes and your eyes adjust to the low light, you get a sense for just how open and surreal the bell-shaped chamber is. I could only imagine what it must have been like for whole bison, horses, and wolves to fall that far down as I gracefully descended to the cave floor. Because we were searching for fossils of all sizes–from bison to mice teeth–we had to look carefully while excavating. That said, a fossil would pop out of the sediment about every ten minutes, which kept things pretty exciting.

horse cannon bone

Horse cannon bone found by Nick Spano. Dental pick for scale.

excavation

Eric Holt carefully excavating a bison dentary to be field-jacketed.

Bison dentary up-close.

Bison dentary up-close.

Once discovered, each fossil needed to be tagged with information about which animal it came from, where in the cave it was found, and what kind of sediment it was found in. We then bagged the specimens and bulk sediments to be screen-washed for microfossils and hauled them back to the surface in a bucket on a rope. In that sense, we were lucky we didn’t find anything bigger than the bucket. Once the excavations were complete, the site was remediated to protect exposed sediments from further weathering and to leave the site in a pristine state for future paleontologists.

screen washing

Eric Holt with a set of drying screen-wash screens.

Now that the final and most recent field season has ended, Natural Trap Cave is closed again for the foreseeable future. Susumu is going through identifications and Jenny is analyzing microfossils from the site. This study will provide a greater understanding of how life was changing in a warming world at the end of the last ice age, with implications for how life might respond to current and projected warming. Eric and I are very thankful to have been volunteers involved with this project and are looking forward to some great results.

Banosky Lab at NTC

Barnosky lab members outside of Natural Trap Cave. From left to right: Nick Spano, Jenny McGuire, Eric Holt, and Susumu Tomiya.


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Author: Helina Chin
UCMP Blog – http://ucmp.berkeley.edu/blog/feed

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Selections Made for the JWST Director’s Discretionary Early Release Science Program

Following the recommendation of the Time Allocation Committee and a thorough technical review, the Space Telescope Science Institute (STScI) Director Ken Sembach has selected 13 science programs for the JWST Director’s Discretionary Early Release Science Program (DD-ERS). It is anticipated that the DD-ERS observations will take place during the first 5 months of JWST science operations, following the 6-month commissioning period.

With a total award of 460 hours of JWST observing time, the selected programs span a wide range of science areas as well as instrument modes, such as surveys of galaxies and their nuclei, stellar clusters and star formation near and far, the chemistry of interstellar and circumstellar matter, and the characterization of exoplanets. The successful programs include 16 Principal investigators (PIs) and co-PIs from North America and 6 from Europe, with broad world-wide participation.

Additional statistics:

  • The selected programs represent participation by 253 investigators from 18 countries, 22 U.S. states, and 106 unique institutions.
  • Of the 253 investigators, 157 are based in the U.S., 84 are from ESA countries, 7 are from Canada, and 5 are from other countries (Australia and Chile), with 248 unique investigators.
  • There are an additional 449 science collaborators involved in the programs. 
  • The three largest teams have combined totals of 138, 105, and 80 investigators and collaborators.

The successful DD-ERS teams are now tasked with developing “science-enabling products,” such as documentation for their programs, scientific software, and data products — all designed to help the full astronomical community maximize the science output of the JWST mission. Continue reading…


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Department News – Department of Astronomy – http://astro.berkeley.edu/news.xml

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Puzzling new supernova may be from star producing antimatter

An exploding star that continued to shine for nearly two years — unlike most supernovae, which fade after a few weeks — is puzzling astronomers and leading theorists, including UC Berkeley astrophysicist Daniel Kasen, to suggest that the event may be an example of a star so hot that it produces antimatter in its core.

Stars would have to be very massive to get this hot, Kasen said, which is why most astronomers assumed they existed, if at all, only in the early years of the universe. Continue reading… 


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Department News – Department of Astronomy – http://astro.berkeley.edu/news.xml

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Astronomers strike cosmic gold

The first detection of gravitational waves from the cataclysmic merger of two neutron stars, and the observation of visible light in the aftermath of that merger, finally answer a long-standing question in astrophysics: Where do the heaviest elements, ranging from silver and other precious metals to uranium, come from?

Based on the brightness and color of the light emitted following the merger, which closely match theoretical predictions by University of California, Berkeley and Lawrence Berkeley National Laboratory physicists, astronomers can now say that the gold or platinum in your wedding ring was in all likelihood forged during the brief but violent merger of two orbiting neutron stars somewhere in the universe.

This is the first detection of a neutron star merger by the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors in the United States, whose leaders were awarded the Nobel Prize in Physics two weeks ago, and the Virgo detector in Italy. LIGO had previously detected gravitational waves from four black hole mergers, and Virgo one, but such events should be completely dark. This is the first time that light associated with a source of gravitational waves has been detected. Continue reading..


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Department News – Department of Astronomy – http://astro.berkeley.edu/news.xml

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Congratulations to Britt Koskella on being Awarded the 2018 Young Investigator Award!

This award recognizes and rewards early career scientists for research excellence and potential in microbiology and infectious disease.

The American Academy of Microbiology is the honorific leadership group within the ASM, the world’s oldest and largest life science organization. The mission of the Academy is to recognize scientists for outstanding contributions to microbiology and provide microbiological expertise in the service of science and the public. 

 


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Author: rhkayen
Integrative Biology – http://ib.berkeley.edu/rss.xml

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Congratulations to Caroline Williams for Being Presented with the George A. Bartholemew Award

Each year the Division of Comparative Physiology and Biochemistry recognizes a young investigator for distinguished contributions to comparative physiology and biochemistry or to related fields of functional and integrative biology. The award offers the awardee a fantastic opportunity to communicate this research via a large lecture at this year’s SICB conference.

Read More About it Here!


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Author: rhkayen
Integrative Biology – http://ib.berkeley.edu/rss.xml

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Faculty Position in Vertebrate Evolutionary Biology

The Department of Integrative Biology and the Museum of Vertebrate Zoology at the University of California, Berkeley invite applications for a full time (50% IB, 50% MVZ) tenure-track position in vertebrate evolutionary biology at the Assistant Professor/Assistant Curator level. Potential start date is July 1, 2018.


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Author: khansen
Integrative Biology – http://ib.berkeley.edu/rss.xml

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