SSS 2010-03-03（在线收听）

Sometimes scientific discoveries are hidden in museum specimen drawers and old journal articles. In two studies in the journal Science, researchers who went through the stuff in institutional attics offer new insights into the development and diversity of filter-feeding whales—and the fish that first occupied that ecological niche.

It had been thought that mammoth, filter-feeding fish—which swam through the water with a gaping, open mouth, collecting tiny marine creatures—only lived fleetingly before whales took their place in the food chain.

But a research team decided to take a closer look at museum fossils of bony, pre-historic fish that had either been misclassified or ignored. They also reexamined previous studies.The investigators now say that these fish filter-feeders lived from about 170 to 65 million years ago, a healthy stretch in which to pioneer and perfect the niche.

In a related study, scientists show that when filter-feeding whales took over from bony fish, their diversity was linked to the diversity of their dinner—the tiny creatures at the very bottom of the food chain –tiny algae known as diatoms.

New insights into some of the largest—and smallest—creatures on the planet.

—Cynthia Graber