Curator to share investigations of limbed vertebrate origins

Ted Daeschler will be the featured speaker for the next Faculty Lecture Series event at 1 p.m. on April 20, in room 302 at the campus in Center Valley. Daeschler, associate curator of vertebrate biology at the Academy of Natural Sciences in Philadelphia, will present "Great Steps in the History of Life: Investigating the Origin of Limbed Vertebrates." This lecture is free and open to the public.

During the presentation, Daeschler will discuss how research on the origin of limbed vertebrates (tetrapods) has made great advances in recent decades as a result of new paleontological discoveries. The fish-tetrapod transition, as it is traditionally called, is no longer an evolutionary leap between free-swimming lobe-finned fish and lumbering tetrapods. A series of fossil intermediates now illustrate the sequence of changes over millions of years in the transformation from finned to limbed members of the tetrapod stem lineage. The interpretation of geological data associated with the fossils has also refined the understanding of the environmental settings that were the crucible of early tetrapod evolution.

"Our exploratory efforts led to the discovery and 2006 description of Tiktaalik roseae, a well-preserved intermediate species in the fish-tetrapod transition. Tiktaalik roseae has primitive features such as scales, fin rays, and a primitive palate and braincase, yet it is replete with derived features such as a neck and modified skull and fin architecture that were previously only recognized in early tetrapods, powerfully demonstrating the concept of mosaic evolution," said Daeschler.

Ted Daeschler started at the Academy of Natural Sciences in 1987 as a collections manager. After receiving his doctorate from the University of Pennsylvania in 1998, he joined the curator ranks. His research has focused on collecting and describing Late Devonian fossil vertebrates from Pennsylvania and the Canadian Arctic including numerous sarcopterygian fishes along the lineage leading to the earliest limbed animals. Daeschler has directed the re-housing of most of the vertebrate paleontology collection at the Academy with an eye toward the long-term conservation of this important historical and scientific resource.

For more information, please contact University Relations at 610-285-5067 or email

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Last Updated January 09, 2015