‘Birds Float’

April 11, 2013

As any biologist will tell you, “Birds float.”

“They’re designed to be light, so they can fly,” says science professor and paleontologist David Krauss.

The downside to buoyancy, though—at least from a paleontologist’s point of view—is that birds are less likely to sink to the bottom of a body of water when they die, become covered with sediment, and fossilize.

And this means less evidence exists today, regarding the world in which they lived.

Clues to earlier eras

“If the birds die on a mud flat, they become fossilized,” Professor Krauss explains. “We know about the water birds, and birds that have died in volcanic eruptions, but not birds that lived in upland environments.”

This is where BMCC science major Ellen Gales became involved, though her path to paleontology has take a few turns—such as earning a bachelor’s degree in archeology from the University of Melbourne, in Australia.

“Since I was six years old, I wanted to be an archeologist,” says Gales, “but then I studied it and did field work and realized archeology focuses on interpretations of human behavior, while I’m much more interested in the evolution and ecology of vertebrate animals that have lived on earth since its formation.”

Within the field of paleontology, her focus is taphonomy, the study of the process of fossilization.

“Eventually, I want to work in a natural history museum in education, with the collections, or conducting museum-sponsored research,” she says, and is getting a feel for that career path by volunteering at the American Museum of Natural History, working with the collections manager, labeling fossils.

Simulating fossilization

Ellen Gales is also completing an honor’s project with Professor David Krauss, analyzing the physical properties of fossilized pigeons and doves he buried almost ten years ago in a simulated environment—even replicating the weight of the millennia by putting them under blocks of granite—at a geoscience summer field camp sponsored by Boston College.

Under Krauss’s supervision, “I’m collating and interpreting the results of that simulation, preparing the fossils, and creating a database relating to real fossilized birds,” says Gales, who wields “a tiny jackhammer,” as she calls it, to isolate particles from the samples.

“I’ll probably transfer to another CUNY college, for a bachelor’s degree in paleontology,” she says, and is considering City College, among others.

The field of paleontology “can eventually guide us in decisions regarding how we manage animal habitats, or help us understand how readily an organism might adapt to a new environment,” she says, adding that it can also “help us manage natural resources, like groundwater.”

Professor Krauss gives another example: “If we understand how ancient marine tidal environments have changed, we can interpret how modern tidal environments have changed.”

He quotes the 19th-century pioneering geologist Charles Lyell, a contemporary of Charles Darwin and who wrote, “The past is the key to the present.”

Krauss is applying that concept to the bird fossil project.

“Our premise is that bird fossils form in mud,” he says. “If you’ve got a bird fossil, you’ve got an intermittently wet and dry environment, like tidal mud flats. It gives us an important clue as to what the environment might have looked like, at that time.”

Krauss and Gales are hoping to present their findings next year, at an international conference of the prestigious Society of Vertebrate Paleontology. “We’ll present first, then publish an article, using feedback we from other scientists at the conference,” Professor Krauss says.


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  • Through Boston College almost ten years ago, Professor David Krauss simulated fossilization conditions for birds
  • In an honor’s project today, his student Ellen Gales is analyzing those fossils for clues to the Eocene and other eras

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