Professor Fisher's current research focuses on the paleobiology and extinction of mastodons and mammoths, elucidated by studies of growth increments and compositional time series (isotopic and elemental) sampled from their tusks and cheek teeth. Fieldwork associated with these projects involves many Pleistocene proboscidean sites in North America (especially the Great Lakes region) and in Siberia. North American occurrences include well preserved mastodon and mammoth skeletons, some showing evidence of human association (hunting, carcass processing). Siberian occurrences include permafrost-derived carcasses with extensive soft-tissue preservation, representing mammoths and other elements of the Mammoth Steppe fauna. Investigations of how teeth record details of animal physiology and life history are supported by studies of tooth formation processes in humans and other mammals. Additional projects have explored use of stratigraphic data in phylogenetic inference; digestive physiology of crocodilians; modes of growth of receptaculitid algae; comparative anatomy, skeletal crystallography, and phylogeny of stylophoran echinoderms; and functional morphology, phylogeny, and macroevolutionary patterns of horseshoe crabs.
Lyuba CT Scan
One of Professor Fisher's research projects focuses on the baby woolly mammoth named Lyuba. At a recent annual meeting of the Society of Vertebrate Paleontology, he and his colleagues (Shirley et al. 2011) presented results derived from CT scans of this specimen, some of which were used to create animations like the one below:
3D Modeling of Mastodon and Mammoth Bones
Professor Fisher’s work on individual specimens and sites often involves construction of 3D models. He and his students typically work with these using specialized graphics software, but they are beginning to use formats that permit more general access. One example of this is a “3D pdf.” The image below is a static rendering of a 3D model of the lower jaw (mandible) of a female mastodon in our collection. To download and view a “live” 3D pdf of this model, click here and then click again on the image that displays after the file is downloaded. It will take a short time for the file (13 MB) to be read by your computer, but once the open file resets, you should be able to rotate and zoom the model of the mandible (requires Adobe Acrobat IX or higher).
To view additional 3D models, browse The University of Michigan Online Respository of Fossils (UMORF) website.