Fish Hips

By Mary Alice Hartsock

The New York Times, The Washington Post, The Boston Globe, BBC News, and countless other newspapers and networks just couldn’t say enough about fish hips. Academy paleontologist and Drexel professor Ted Daeschler had 10 years of research behind this coverage, and he watched as the world reacted to this scientific breakthrough.

It wasn’t the first time that he and his research partner and coauthor Dr. Neil Shubin (The University of Chicago) had their work broadcast across major news outlets. The recent announcement focused on new fossil material of the internationally famous 375-million-year-old species Tiktaalik roseae, discovered a decade ago by Daeschler, Shubin, and the late Farish A. Jenkins, Jr., of Harvard University.

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Tiktaalik roseae by Ted Daeschler/ANS

Offering a textbook example of the evolutionary transition between finned and limbed animals, Tiktaalik roseae was a lobefinned fish with many features only seen in tetrapods (limbed animals). The new findings, published in the Proceedings of the National Academy of Sciences in January, reveal a well-preserved pelvis and partial pelvic fin that demonstrate that the evolution of robust pelvic appendages happened before the origin of limbs—not after, as scientists originally thought. Daeschler explains that these rear appendages enabled a shift from “front-wheel drive” to “four-wheel drive” movement in fish, rather than in limbed animals.

In the past two years, Daeschler and the team closely examined material from the back end of Tiktaalik, which they had gathered during multiple expeditions to Canada’s Nunavut Territory. Tiktaalik’s “fish hips” quickly drew attention as the researchers noticed that, although the basic architecture of the pelvis was primitive, there were also distinct similarities to tetrapods. Like tetrapods, Tiktaalik had similarly sized front and rear appendages, plus a ball-and-socket hip joint that allowed the pelvic fin a greater range of motion, including beneath the body.

According to Daeschler, Tiktaalik used the fin similarly to the way tetrapods used their limbs, but mostly in aquatic settings. Daeschler and Shubin’s significant discovery fills yet another gap in our knowledge of evolution from creatures of water to those of land.

Ted Daeschler in Nunavut, Canadian Arctic. Photo: Josh Miller
Ted Daeschler in Nunavut, Canadian Arctic by Josh Miller

Now, the extraordinary creature, also known as the “fishapod,” will be on public display from Saturday, May 2, through Sunday, June 7 at the Academy. The exhibit includes a touchable cast of the skull, a collection of items including toys that reference Tiktaalik, and a video of Daeschler’s appearance on the “Colbert Report” shortly after the discovery was announced in 2006 in the journal Nature.

On Wednesday, May 6, Daeschler will recount his amazing adventures—and hardships—during nine expeditions to Ellesmere Island, Nunavut, north of the Arctic Circle, where his team discovered Tiktaalik and many other fossils. Those nine trips also included ventures to explore Devonian-age formations across a wide swath of the Arctic Islands and into other geologic formations that Daeschler believes may harbor important new discoveries.

The illustrated presentation is free and begins at 7 p.m. Registration is available at farewelltofins.eventbrite.com.

On Sunday, June 7, the Academy is hosting a Tiktaalik Day! On the last day of the exhibit, there will be additional family activities, including hands-on games, crafts, a “Family Reunion” live animal show at 11 a.m., and a “Tick Tock Tiktaalik” interactive stage show at 3 p.m. At 1 p.m. Daeschler will share stories of his explorations in the inhospitable terrain of the Arctic. The events are free with regular admission. For details, visit ansp.org.

Portions of this article originally appeared in the spring 2014 issue of Academy Frontiers.

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