Natural History

Extinct giants, a new and the key to understanding climate change

After its last excavation in the 1970s, a group of palaeontologists, In an attempt to better understand the genetics experts and cavers led by vertebrate palaeontologist and factors that influenced this mass and how climate change affects mammalian carnivore specialist of Des Moines By William Harris (Own Dr Julie Meachen populations, Dr Meachen along with work) [CC BY-SA 4.0 University, have re-opened excavations at (NTC) in co-investigator Dr Alan Cooper and her (http://creativecommons. org/licenses/by-sa/4.0)], North America. During this project, Dr Meachen hopes to uncover the collaborative team have been studying via Wikimedia Commons secrets of the mass extinction of the last ice age and give high school the remains of megafauna excavated from students the opportunity to get involved in Palaeontology. Natural Trap Cave in Wyoming, North America. Today, we are experiencing a sixth mass extinction, with climate change and influence believed to be at its heart. efore the withdrawal of the last typically weighing more than 44kg The research at Natural Trap Cave (NTC) ice age in the late and iconic to this time – such as mastodons, could not only uncover information about some 10,000 years ago, dire and sabre-toothed cats, the events leading to the loss of the ice diversity was much richer than roamed the Earth. Now, these species are age’s megafauna, but may also help us to it is today. Many Pleistocene extinct, with climate change being one understand how climate change has played a species were bigger, more varied in of the contributing factors in a complex role in the current extinction crisis. Bappearance and roamed in greater numbers extinction event that saw a dramatic loss of than those we see now. Megafauna – large diversity. A GLIMPSE INTO THE PAST Natural Trap Cave is a pit cave in North America. During the Pleistocene, this natural deadfall trap would have been located south The research at Natural Trap Cave of the Cordilleran and Laurentide ice sheets– glaciers that were separated by a channel (NTC) could help us to understand how leading from into North America. NTC climate change has played a role in the lies just south of where this corridor between the ice sheets would have ended. Previous current extinction crisis research has revealed that prey and predator species would have used this channel as a migration route into new territories. During this migration, some animals would fall into Dr Julie Meachen rappels into Natural Trap Cave the cave due to the sheer 85-foot drop. Any animals that managed to survive the fall would © Justin Sipla be unable to escape, leading to an abundance of well-preserved Pleistocene fossils.

NTC has protected the wealth of skeletons that litter its floor for thousands of years by keeping temperatures below 10°C and preventing weathering from wind and rain. As a result, the fossils recovered from the site are often of unusually high quality and many are almost fully intact, allowing for a unique look at the past ecosystems from 2016 of America. Some of the most complete Natural Trap Cave American Cheetah (Mirancinonyx trumani) excavations. © Julie Meachen specimens have been recovered from this site, as well as an extinct species of Musk-

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Detail © Justin Sipla

© Julie Meachen RESEARCH OBJECTIVES Dr Meachen and her team are currently What first interested you in Natural Trap makes me wonder if there are any living working at Natural Trap Cave, where Cave (NTC)? Grey wolves out there that may carry some they are excavating Ice Age I knew about NTC, but never gave it much hidden Beringian alleles in their DNA. to determine how climate change and thought until I met my Co-PI Dr Alan the extinction events at the end of the Cooper at a group meeting at the National Why do you think it is important to Pleistocene (10,000 years ago) have Evolutionary Synthesis Center in Durham, engage children in science? affected the and ecology NC. He suggested we go back to NTC to Children are the next generation of adults, of living and Pleistocene species. get ancient DNA from the source. After and right now, it is more important than Additionally, they are using a microfaunal that, it took us a few tries to get funding, ever to pique their curiosity about the and pollen record to recreate Pleistocene but once we did, the project was off and natural world and encourage them to ask climate in mid-latitude North America. running. questions about how the world around them works. I would really love to inspire FUNDING How does your work at NTC change our future generations of scientists to carry National Science Foundation (NSF) understanding of the current extinction on important work on climate change and crisis and climate change? animal/habitat . COLLABORATORS Our work explores the link between • Dr Alan Cooper – Australian Centre for Left: A view of Natural Trap Cave. genetics, morphology, and the What do you hope to achieve with your Ancient DNA (ancient DNA analysis) Right: An Ice Age coyote jaw from 2016 environment. So hopefully we will be able next excavation in 2017? • Dr Pennilyn Higgins – U Rochester Natural Trap Cave excavations. to answer questions about how climate We hoped to fill in some gaps in the (stable ) affects genes, morphology, and the microfauna fossil record that we had • Dr Jenny McGuire – Georgia Tech likelihood that a species will go extinct. previously missed – and we collected (microfaunal analysis) oxen ( bombifrons) and several studied NTC wolves in the past had trouble and would have arrived at NTC by following about 40 bags of cave dirt to do just that. • Dr Cory Redman – Drake University specimens of unclassified wolves. categorising the skeletons they uncovered the migration of musk-oxen and bison. What can we learn about modern Grey Hopefully we will get the microfauna we ( ecology) – former postdoc because Beringian wolves are very similar Dr Meachen believes the migration of wolf populations from this research? need! We also were looking for some good • Dr Susumu Tomiya – DMU (mammal NTC was first revisited in 2014, with another to both extinct Dire wolves ( dirus) and Beringian wolves into mid-continental Hopefully this work will give us insights ancient DNA specimens of wolves, coyotes, morphology & ecology) – current two field sessions in 2015 and 2016 providing today’s Grey wolves (Canis lupus). However, America may offer insights into the into when Grey wolves came into North bison, and horses – and I think we’ve also postdoc excellent data. Using DNA found in the bones by analysing DNA recovered from specimens dispersion of the Grey wolf – a species America, and it has opened the door to got some good candidates there! • Dr Tom Minckley – U Wyoming (pollen and teeth of long extinct animals, pollen at NTC, and measurements taken from jaw which once covered the entire Northern questions about how widespread the analysis) samples and records from the site’s last bones and teeth, Dr Meachen’s collaborative Hemisphere. A last field session in 2017 Beringian morph was in North America. It excavation, Dr Meachen and her collaborative team could establish that the wolves of NTC promises to further explore how climate BIO team have been able to assess the anatomy are distinct from Dire wolves. change in the affected Dr Julie Meachen completed and appearance of species, their diet and these megafaunal populations. her PhD in Ecology and the environmental conditions during a time A little smaller than a and with a Evolutionary Biology at the of rapid climate change. This information higher bite force and longer snout than Grey BRINGING THE ICE AGE TO SCHOOL University of California in has helped to broaden understanding wolves, Beringian wolves lie somewhere Barefoot is an educational outreach 2008 and is now a vertebrate of how animals may have responded to between the two species in appearance and team looking to make science relatable palaeontologist and functional environmental changes brought about by a are believed to be an ecomorph of Canis for children. Founder James MacDiarid morphologist that specialises in warming climate, by revealing immigration lupus. In other words, Beringian and Grey has dedicated a decade of his career to mammalian carnivores at Des Moines patterns and changes in anatomy. wolves were the same species, but due to bringing accurate science to students University. exposure to different conditions, such as through videos and video-telecasting. A DIFFICULT WOLF TO CLASSIFY prey availability, differences in temperature Barefoot’s goal is to encourage children to CONTACT One of the key findings by the team at NTC and precipitation rates, they developed ‘Imagine, learn and connect’ with science Dr Julie Meachen has been that of specimens. separate, distinct characteristics. using stories to explain complex content. Assistant Professor The recently classified Alaskan Beringian Des Moines University wolf had not previously been identified as Further study revealed that these animals In 2016, Barefoot were invited to join Dr 3200 Grand Avenue, far south as Wyoming. Researchers who were likely to be megafaunal prey specialists Meachen and her collaborative team at Des Moines, IA 50312 NTC, where they held skype sessions with USA students in Australia and England, bringing Dr Meachen believes the migration of the excitement and wonder of the ice age E: [email protected] directly into the classroom. It is the hope T: +1 515 271 1568 Beringian wolves into mid-continental America of both Barefoot and the NTC researchers, W: www.dmu.edu/ that by working together to engage with may offer insights into the dispersion of the students they can provide an insight into Grey wolf – a species which once covered the how an excavation is carried out and what it is like to uncover the bones of long dead Photo of the partial field crew in 2014, from left to right: Kim Scott, Eric Scott, Jessica Miller-Camp, Julie Meachen, entire Northern Hemisphere giants. John Logsdon, Jenny McGuire, and Gretchen Hurley (BLM)

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