My overarching research focus is documenting and explaining the ecological consequences of major evolutionary changes within a single environment during the Cambrian through Devonian, the first 200 million years of abundant animal life. This time period is important because of the significant evolutionary and ecological reorganization it witnessed, including the origin of most animal classes and a tripling of the number of species within communities. My data—publicly available through the Paleobiology Database—consists of nearly 450 fossil collections representing more than 7000 fossil species and 77,000 individuals compiled from literature, museum, and my own field collections. Because these communities contain few species in common, I have developed a comparative framework (Novack-Gottshall 2007) focusing instead on the ecological—and consequently often convergent—characteristics (such as body size, diet, foraging habit, microhabitat, etc.) of the organisms making up these communities. A striking result (symbolized by the photomosaic above) is that 450-million-year-old marine biotas seem to be similar ecologically to those living today in the Gulf of Carpentaria (Australia) and the North American Atlantic Shelf.
For example, the figure above (Fig. 3 from Novack-Gottshall 2007) demonstrates that a large sample of the modern biota has only slightly more life habits per sampling unit that does a comparable sample of Paleozoic fossil assemblages. This is especially surprising because the modern biota here includes soft-bodied animals that are not usually fossilized. This outcome is unexpected because the faunas contain no families and even few classes in common, and it points toward a similarity in how communities are assembled that is not anticipated by the many major ecological changes in the history of marine life. In contrast, the life habits in the modern biota are significantly more distinctive from one another (measured as ecological disparity, the mean Euclidean distance between pairs of life habits) than are those in the Paleozoic. The causes of this increased distinctiveness are unclear and under investigation.
Representative publications:
Novack-Gottshall, P.M. 2007. Using a theoretical ecospace to quantify the ecological diversity of Paleozoic and modern marine biotas. Paleobiology 33: 274-295 (.pdf)