Rachel Racicot received the 2014 George Gaylord Simpson Prize for her publication, "Unique feeding morphology in a new prognathous extinct porpoise from the Pliocene of California" (Current Biology 24: (7) 774-779, coauthored with T.A. Deméré, B.L Beatty and R.W. Boessenecker). The paper describes a new porpoise species, Semirostrum ceruttii, which existed 5-2 million years ago. It had a long, thin lower jaw extending significantly beyond the upper jaw, a unique characteristic for a mammal. CT scans showing elongate nerve canals within the unusual jaw indicate that Semirostrum likely used it to feel around for food near the seafloor.
Stephen Chester received the 2014 George Gaylord Simpson Prize for his 2013 publication “Systematics of Paleogene Micromomyidae (Euarchonta, Primates) from North America” (Journal of Human Evolution 65: 109-142, coauthored with Jonathan Bloch). This study stems from Chester’s dissertation research on the origin and earliest evolutionary history of primates. This paper describes many new fossils of micromomyid plesiadapiforms, the most primitive stem primates for which skeletons are known. Micro-CT scanning technology was used to study internal aspects of specimens and to digitally reconstruct important broken fossils of micromomyids. Virtually all known micromomyid fossils were analyzed to assess the existing alpha taxonomic framework for the Micromomyidae. Intraspecific variability was analyzed, taxonomy was revised, and the first major phylogenetic analysis of micromomyid interrelationships was performed. Results demonstrate several patterns of tooth shape and size, as well as trends in body mass, throughout the evolution of this family of plesiadapiforms.
Chester is an Assistant Professor of Anthropology at Brooklyn College, City University of New York, and a Resource Faculty Member at the New York Consortium in Evolutionary Primatology. He studies fossil mammals from the Late Cretaceous to the early Eocene with particular focus on the Cretaceous-Paleogene extinction event and the Paleocene-Eocene Thermal Maximum, which are both very significant events in mammalian and early primate evolution.