Sharks that pass in the night: using Geographical Information Systems to investigate competition in the Cretaceous Western Interior Seaway

Abstract

One way the effects of both ecology and environment on species can be observed in the fossil record is as changes in geographical distribution and range size. The prevalence of competitive interactions and species replacements in the fossil record has long been investigated and many evolutionary perspectives, including those of Darwin, have emphasized the importance of competitive interactions that ultimately lead one species to replace another. However, evidence for such phenomena in the fossil record is not always manifest. Here we use new quantitative analytical techniques based on Geographical Information Systems and PaleoGIS tectonic reconstructions to consider this issue in greater detail. The abundant, well-preserved fossil marine vertebrates of the Late Cretaceous Western Interior Seaway of North America provide the component data for this study. Statistical analysis of distributional and range size changes in taxa confirms earlier ideas that the relative frequency of competitive replacement in the fossil record is limited to non-existent. It appears that typically, environmental gradients played the primary role in determining species distributions, with competitive interactions playing a more minor role.

The Geography of Evolution and the Evolution of Geography

“…Integrating these new methodological developments with polygons show the ranges for the mosasaur Tylosaur. These ranges change through time but do not show a statistical association with one another and instead appear to be associated with changes in the environment, from Myers and Lieberman (2011), used with permission important theoretical insights holds major promise for the future of biogeography and charts a pathway connecting past and future discoveries.…”

“…One instance where such techniques have proven valuable is in showing the role that invasive species played in causing the Late Devonian biodiversity crisis Lieberman 2004, 2005;Stigall 2010). Another instance where GIS has proven valuable in the analysis of geographic data from fossils is in studies looking at the role competition plays in macroevolution (Myers andLieberman 2011). Darwin (1859), Dawkins (1976), and many others have argued that competition is a significant evolutionary force, yet evidence from the fossil record has always been limited (Gould and Calloway 1980; Fig.…”

“…Darwin (1859), Dawkins (1976), and many others have argued that competition is a significant evolutionary force, yet evidence from the fossil record has always been limited (Gould and Calloway 1980; Fig. 1 Occurrence records for some Late Cretaceous marine vertebrates, a shark (light gray) and a mosasaur (dark gray), shown on a map of the modern world (a) and the Cretaceous world (b), from Myers and Lieberman (2011), used with permission Benton 1996). GIS provides an excellent means to consider how the geographic ranges of species interact with one another through time.…”

“…GIS provides an excellent means to consider how the geographic ranges of species interact with one another through time. Myers and Lieberman (2011) used the GIS to consider the geographic ranges of several fossil marine vertebrate species from the Cretaceous Western Interior Seaway, a large, mostly tropical seaway running up through the center of North America (Fig. 1) that is the source of numerous, extensive fossil marine deposits.…”

“…1) that is the source of numerous, extensive fossil marine deposits. Myers and Lieberman (2011) specifically focused on whether there was any evidence for competitive replacement: a phenomenon where one species appears within another species' geographic range, its range expands, and it slowly and gradually drives the other species to extinction. They found no statistical evidence for competitive replacement.…”