Fossils play an important role in our understanding of life on Earth. Studying past climate change and mass extinction events can tell us a lot about how species evolve and recover following dramatic change. For instance, Antarctica was not always the icy, inhospitable place it is today. The discovery of land-living, backboned animals in 251-million-year-old Triassic rocks tells us that a wide variety of life once existed on the continent. This has led to a deeper understanding of the evolution of life at high latitudes as well as how Antarctica’s climate has dramatically warmed and cooled.
Approximately 250 million years ago during the Triassic period, Antarctica was part of the supercontinent of Pangea.
During this time, all of the continents were assembled into a large and continuous land mass that was free of polar ice and all of the oceans were combined into one large oceanic mass (Panthalassa).
Pangea drifted slowly northwards during the Triassic until the supercontinent began to divide in the Early Jurassic (about 180 million years ago).
Months prior to the expedition, team members underwent rigorous equipment and survival trainings to prepare for the difficult conditions.
When departure day arrives, the team boards a U.S. Air Force Air National Guard plane in Christchurch, New Zealand, for the flight to Antarctica. This photo shows a LC-130 Hercules, which is a ski-equipped cargo plane that can land on a snow runway.
Most researchers working in the Transantarctic Mountains begin their journey at McMurdo Station, the primary base of the U.S. Antarctic Program. The population of McMurdo can reach upwards of 1,000 people during the austral summer, but goes down to about 200 during the long, dark polar winter.
After leaving McMurdo Station, the team headed to the Central Transantarctic Mountain (CTAM) base camp where they were based for nearly two months. The CTAM base camp hosted up to 80 scientists researching a wide variety of subjects, such as geology, geophysics, glaciology, atmospheric sciences, and even microscopic organisms that are found exclusively near the south pole.
One of the biggest misconceptions about fieldwork in Antarctica is that paleontologists dig through snow and ice to get to rock—thankfully, this is not true! Depending on the time of year and prevailing winds, large areas of rock outcrops can be exposed. In this photo, Brandon Peecook is seen examining a fossil still in the rock.
The team spends each day recording the geology, searching for fossils, and excavating any important finds. The sun doesn’t set during December and January, so a day of work could last a long time!
This is what a fossil looks like at the moment of discovery. Would you be able to recognize it? The white area below the brush is part of the mandible of a giant temnospondyl. Once fully excavated and then prepared, these jaws turned out to be almost a meter long.
This is the Lystrosaurus fossil that was sketched in the field notebook. On the left is visible some of the vertebral column and ribs, whereas on the right are the forelimbs.
To remove the fossil, they cut a border around it with the rock saw and then drive large chisels underneath the fossil to “pop” it out (along with a slab of rock).
Lystrosaurus was a dog-sized herbivore and are the most common vertebrate remains found in the lower Fremouw Formation. Lystrosaurus fossils have also been discovered in South Africa, China, Russia and possibly Australia, meaning that the species was extremely widely dispersed. In fact, this broad geographic distribution is one of the pieces of evidence of the supercontinent of Pangea.
This illustration depicts what Lystrosaurus (top, right) and Thrinaxodon (bottom, left), a cat-sized animal that likely fed on insects and other invertebrates, might have looked like in life.
This is a slightly jumbled skeleton of the second fossil that was found directly underneath the Lystrosaurus specimen in the earlier field excavation photos. It belongs to the early dinosaur relative, Prolacerta.
Prolacerta was lizard-like in its size and overall body shape, but details of its anatomy point to it being more closely related to crocodiles and dinosaurs.
Today, the Antarctic fossils are part of the Burke Museum’s paleontology collection where we care for more than three million fossil vertebrates (animals with a backbone), invertebrates (animals without a backbone), plants, microfossils and trace fossils.
They are organized in large cabinets and are available to researchers around the world to study.
The fossils discovered in the 2010-11 expedition help us to better understand what animals once thrived in Antarctica’s warmer climate and how they were affected by climate change and mass extinctions over time.
The Burke team is planning to return to Antarctica in 2017-18 to the Shackleton Glacier area, which was last explored by paleontologists more than 30 years ago. This is an exciting opportunity to uncover even more fossils that shed light on how animals relate to each other worldwide and diversified over time.
Christian Sidor’s research on the Antarctic fossil record has been supported by several grants from the National Science Foundation (NSF-PLR 0551163, PLR 0838762, PLR 1146399). Team members for the 2010-11 field season were Adam K. Huttenlocker, Brandon R. Peecook, and Roger M.H. Smith.
Exhibit created by Christian Sidor and Cathy Morris, Burke Museum of Natural History and Culture.