Physical Sciences and Mathematics Commons^™

Devonian Stromatoporoid Interactions At The Falls Of The Ohio State Park, Clarksville, Indiana, Morgan Sierra Hall

Undergraduate Theses

Stromatoporoids are calcitic sponges that occurred in the fossil record from the Early Ordovician to Late Devonian period. These sponges interacted with other organisms, especially rugose and tabulate corals. Some corals appear to benefit from the rigidity of stromatoporoids in response to turbulent waters. Stromatoporoids and many corals went extinct during the Frasnian-Famennian crisis when paleoenvironmental parameters were shifting. Studying the relationships between these taxa may provide insight to their vulnerability during the extinction.

This research was performed at the Falls of the Ohio in Clarksville, Indiana. Organisms in the Coral Zone were studied using transect sampling. Each fossil along …

Climate Change, Managed Relocation, And The Risk Of Intra-Continental Plant Invasions: A Theoretical And Empirical Exploration Relative To The Flora Of New England, Jesse Bellemare, Bryan Connolly, Dov F. Sax

Biological Sciences: Faculty Publications

The high rate of anthropogenic climate change projected for coming decades and evidence of low migration ability for many species have led researchers to warn of a looming extinction crisis. This threat is expected to be most acute for small-ranged endemic species, which could see novel climatic conditions develop rapidly across the entirety of their limited geographic ranges. To avoid extinctions, some conservationists have proposed that climateimperiled species might be candidates for "assisted colonization" or "managed relocation" to new regions, outside their historical ranges. One major concern related to managed relocation is the possibility that some relocated species could later …

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …