Finding Fossils in an Antarctic Summer
by AMNH on
For background on the Antarctic Peninsula Paleontology Project and the Museum students and curators that were part of it, read this blog post from last week!
In the early months of 2016, Museum Curators Jin Meng and Ross MacPhee, as well as Ph.D.-degree student Abagael West, visited the James Ross Island Group in Antarctica as part of the Antarctic Peninsula Paleontology Project (AP3), and international fossil-finding expedition. AP3 teams spent several weeks divided among field camps at four separate sites, with short trips to other locations by helicopter and Zodiac motorboat.
The glamour of island-hopping by helicopter didn’t diminish the grueling work of finding fossils, a down and dirty exercise pursued on all fours while searching through frigid, densely packed mud, sand, and gravel.
The odds of finding mammalian fossils were always low, in part because the islands are largely composed of shallow marine sediment, topped with volcanic deposits. That’s a great place to find fish fossils like shark teeth, which the team discovered in abundance, but not ideal hunting grounds for mammal fossils.
“These islands are not where mammals would have been living, because they only uplifted a few million years ago,” points out MacPhee. “The teeth and small fragments of land vertebrates would have come in from elsewhere, and would have been carried to sea by a river, swept out into shallow waters, and remained there.”
That’s certainly a possible course of events—fossils of Eocene mammals from about 45 million years ago were found on this and earlier expeditions. But it makes finding more ancient mammal specimens a very tall order, especially considering that such fossilized remains would be from species probably not much larger than a rat.
In the end, the team’s efforts did not turn up the Cretaceous-era mammals MacPhee his colleagues had hoped to uncover. But there were plenty of other collections made—many hundreds of fossils in total—as well as a few additional interesting and important findings.
One was a closer study on a layer of fish fossils on Seymour Island located just above the boundary layer which marks the impact that wiped out the dinosaurs. While this important marker, known as the K-Pg boundary, is well understood and identifiable at numerous sites around the world, places where mass die-offs are directly associated with the impact are rare.
“It’s possible that the deaths of these fish and other organisms was caused by the impact,” says Meng. “There’s no direct evidence yet, but we’re looking into whether we can establish that connection.”
MacPhee and his colleagues also brought home a few fossils from a well-studied species of exctinct Eocene penguin. These fossils are not destined for Museum collections but for so-called “destructive sampling.” MacPhee hopes to extract collagen proteins, which can last for millions of years longer than DNA, from these specimens. Collagen is produced by only a few genes and so cannot provide as much information as DNA sequences. However, recent work reveals that even a small amount of protein sequence information can shed light on evolutionary relationships between ancient organisms.
Given the challenges implicit in finding bones that are millions of years old and the compounding difficulties of working in one of the world’s most inhospitable environments, if there’s one thing that Antarctica rewards, it is flexibility and willingness to embrace scientific work as it presents itself.
“In this kind of fieldwork, you have your reasons for wanting to go to a place, but you don’t always get what you want,” says MacPhee. “Sometimes, though, you end up finding something even more interesting.”
A version of this story originally appeared in the Summer 2016 issue of the Member magazine Rotunda.