February 2, 2022
12:00pm, PST Zoom
University of Southern California
" A Fistful of Molars: New Fossil Collections & Biomedical Imagine Applications Reveal How Nonmammalian Synapsids Won the Paleozoic West "
Today, mammals are found on all continental land masses, in the air, and in the seas. But their modern diversity belies an earlier radiation of amniotes that pioneered terrestrial ecosystems during the “first age of mammals”: the nonmammalian synapsids. What lesson do these ancient pioneers offer about the expansion of mammalian functional ecology and their unlikely survival during two of life’s greatest upheavals: the Late Paleozoic Ice Ages (LPIA) and the Permo-Triassic mass extinctions? The first part of this talk features new discoveries in paleotropical western Pangea, and emphasizes the importance of southern Utah’s Bears Ears National Monument in archiving these ancient ecosystems. Multiproxy data show that contractions of tropical wetlands gave way to emerging dryland-adapted, amniote-dominated faunas from a western Pangean epicenter during the peak LPIA, several million years earlier than previously thought. Paleophysiological studies may support important functional changes that permitted synapsids to expand their thermal niche into higher latitudes during Middle and Late Permian times along with the waning of continental glaciers. The second part of this talk journeys to South Africa’s Karoo Basin and Antarctica, which preserve the most complete and continuous record of mammal-like synapsids spanning Earth’s most severe biodiversity crisis: the Permo-Triassic mass extinctions. Studies of Karoo synapsid body size distributions and skeletochronology reveal unique growth patterns, possibly in response to environmental instability and resource depletion, and highlight a ubiquitous and poorly-understood pattern of post-extinction communities: the “Lilliput effect.” We conclude by examining the surprising parallels to our current biodiversity crisis—the sixth mass extinction—and the challenges faced by synapsids today.
Seminar will be live-streamed via Zoom
Meeting ID: 995 9733 0541
Host: Karen Sears