Earth and Environment Dr Julie Meachen ︱ efore the withdrawal of the last Dr Julie Meachen rappels into Natural Trap Cave ice age in the late Pleistocene © Justin Sipla Bsome 10,000 years ago, species diversity was much richer than it is today. Many Pleistocene species were bigger, more varied in appearance and Extinct giants, a new roamed in greater numbers than those we see now. Megafauna – large animals typically weighing more than 44kg and iconic to this time – such as mastodons, dire wolves and sabre-toothed cats, wolf and the key roamed the Earth. Now, these species are extinct, with climate change being one of the contributing factors in a complex extinction event that saw a dramatic loss to understanding of diversity. In an attempt to better understand the factors that inluenced this mass extinction and how climate change affects animal populations, Dr Meachen climate change along with co-investigator Dr Alan Cooper and her collaborative team have been studying the remains of After its last excavation in the 1970s, a group of palaeontologists, genetics experts and cavers led by vertebrate megafauna excavated from Natural to an abundance of well-preserved Dr Meachen and her collaborative team palaeontologist and mammalian carnivore specialist Dr Julie Meachen of Des Moines University, have re-opened Trap Cave in Wyoming, North America. Pleistocene fossils. have been able to assess the anatomy excavations at Natural Trap Cave (NTC) in North America. During this project, Dr Meachen hopes to uncover the Today, we are experiencing a sixth and appearance of species, their diet secrets of the mass extinction of the last ice age and give high school students the opportunity to get involved mass extinction, with climate change NTC has protected the wealth of and the environmental conditions in Palaeontology. and human inluence believed to be at skeletons that litter its loor for during a time of rapid climate change. its heart. The research at Natural Trap thousands of years by keeping This information has helped to broaden Cave (NTC) could not only uncover temperatures below 10°C and understanding of how animals may have information about the events leading preventing weathering from wind and responded to environmental changes to the loss of the ice age’s megafauna, rain. As a result, the fossils recovered brought about by a warming climate, but may also help us to understand how from the site are often of unusually by revealing immigration patterns and climate change has played a role in the high quality and many are almost fully changes in anatomy. http://creativecommons. current extinction crisis. intact, allowing for a unique look at the past ecosystems of America. Some of A DIFFICULT WOLF TO CLASSIFY A GLIMPSE INTO THE PAST the most complete American Cheetah One of the key indings by the team at Natural Trap Cave is a pit cave in North (Mirancinonyx trumani) specimens have NTC has been that of Beringian wolf America. During the Pleistocene, this been recovered from this site, as well specimens. The recently classiied )], via Wikimedia Commons via )], natural deadfall trap would have been as an extinct species of Musk-oxen Alaskan Beringian wolf had not located south of the Cordilleran and (Bootherium bombifrons) and several previously been identiied as far south Laurentide ice sheets– glaciers that were specimens of unclassiied wolves. as Wyoming. Researchers who studied separated by a channel leading from NTC wolves in the past had trouble Alaska into North categorising the org/licenses/by-sa/4.0 By William Harris (Own work) [CC BY-SA 4.0 ( America. NTC lies skeletons they just south of where The research at Natural Trap Cave (NTC) uncovered because this corridor between Beringian wolves the ice sheets could help us to understand how climate are very similar would have ended. to both extinct Previous research change has played a role in the current Dire wolves (Canis has revealed that extinction crisis dirus) and today’s prey and predator Grey wolves (Canis species would lupus). However, have used this channel as a migration NTC was irst revisited in 2014, with by analysing DNA recovered from route into new territories. During this another two ield sessions in 2015 and specimens at NTC, and measurements migration, some animals would fall into 2016 providing excellent data. Using taken from jaw bones and teeth, Dr Holocene bison skull from 2016 the cave due to the sheer 85-foot drop. DNA found in the bones and teeth of Meachen’s collaborative team could Natural Trap Cave excavations. © Julie Meachen Any animals that managed to survive the long extinct animals, pollen samples and establish that the wolves of NTC are fall would be unable to escape, leading records from the site’s last excavation, distinct from Dire wolves. www.researchoutreach.org www.researchoutreach.org Behind the Bench Dr Julie Meachen E: [email protected] T: +1 515 271 1568 W: www.dmu.edu/ Dr Julie Meachen Research Objectives Collaborators Assistant Professor Dr Meachen and her team are currently • Dr Alan Cooper – Australian Centre for Left: A view of Natural Trap Cave. © Justin Sipla Des Moines University working at Natural Trap Cave, where Ancient DNA (ancient DNA analysis) Right: An Ice Age coyote jaw from 2016 Natural 3200 Grand Avenue, they are excavating Ice Age mammals • Dr Pennilyn Higgins – U Rochester Trap Cave excavations. © Julie Meachen Des Moines, IA 50312 to determine how climate change (stable isotope analysis) USA and the extinction events at the end • Dr Jenny McGuire – Georgia Tech prey specialists and would have arrived of the Pleistocene (10,000 years ago) (microfaunal analysis) Bio A little smaller than a Dire wolf and with at NTC by following the migration of have affected the morphology and • Dr Cory Redman – Drake University Dr Julie Meachen completed her PhD ecology of living and Pleistocene (mammal ecology) – former postdoc a higher bite force and longer snout to different conditions, such as prey musk-oxen and bison. Dr Meachen in Ecology and Evolutionary Biology at species. Additionally, they are using • Dr Susumu Tomiya – DMU (mammal than Grey wolves, Beringian wolves lie availability, differences in temperature believes the migration of Beringian the University of California in 2008 and a microfaunal and pollen record to morphology & ecology) – current somewhere between the two species and precipitation rates, they developed wolves into mid-continental America is now a vertebrate palaeontologist and recreate Pleistocene climate in mid- postdoc in appearance and are believed to be separate, distinct characteristics. may offer insights into the dispersion functional morphologist that specialises latitude North America. • Dr Tom Minckley – U Wyoming (pollen an ecomorph of Canis lupus. In other of the Grey wolf – a species which in mammalian carnivores at Des Moines analysis) words, Beringian and Grey wolves were Further study revealed that these once covered the entire Northern University. Funding the same species, but due to exposure animals were likely to be megafaunal Hemisphere. A last ield session in 2017 National Science Foundation (NSF) promises to further explore how climate change in the late Pleistocene affected Dr Meachen believes the migration of these megafaunal populations. Beringian wolves into mid-continental America BRINGING THE ICE AGE TO SCHOOL Barefoot is an educational outreach may offer insights into the dispersion of the team looking to make science relatable Grey wolf – a species which once covered the for children. Founder James MacDiarid able to answer questions about how than ever to pique their curiosity about has dedicated a decade of his career to Q&A climate affects genes, morphology, the natural world and encourage them entire Northern Hemisphere bringing accurate science to students and the likelihood that a species will go to ask questions about how the world through videos and video-telecasting. What irst interested you in Natural extinct. around them works. I would really Barefoot’s goal is to encourage children Trap Cave (NTC)? love to inspire future generations of to ‘Imagine, learn and connect’ with I knew about NTC, but never gave it What can we learn about modern Grey scientists to carry on important work science using stories to explain complex much thought until I met my Co-PI Dr wolf populations from this research? on climate change and animal/habitat content. Alan Cooper at a group meeting at the Hopefully this work will give us insights extinctions. National Evolutionary Synthesis Center into when Grey wolves came into North In 2016, Barefoot were invited to join Dr in Durham, NC. He suggested we go America, and it has opened the door to What do you hope to achieve with Meachen and her collaborative team at back to NTC to get ancient DNA from questions about how widespread the your next excavation in 2017? NTC, where they held skype sessions the source. After that, it took us a few Beringian morph was in North America. We hoped to ill in some gaps in the with students in Australia and England, tries to get funding, but once we did, It makes me wonder if there are any living microfauna fossil record that we had bringing the excitement and wonder of the project was off and running. Grey wolves out there that may carry previously missed – and we collected the ice age directly into the classroom. some hidden Beringian alleles in their about 40 bags of cave dirt to do It is the hope of both Barefoot and How does your work at NTC change DNA. just that. Hopefully we will get the the NTC researchers, that by working our understanding of the current microfauna we need! We also were together to engage with students they extinction crisis and climate change? Why do you think it is important to looking for some good ancient DNA can provide an insight into how an Our work explores the link between engage children in science? specimens of wolves, coyotes, bison, excavation is carried out and what it is genetics, morphology, and the Children are the next generation of and horses – and I think we’ve also got like to uncover the bones of long dead environment.