Sarda Sahney - Department of Earth Sciences, University of Bristol, England

Sarah King, MSc 2007 - Pennsylvanian terrestrial ecosystems of Atlantic Canada
		Supervisors: Howard Falcon-Lang and Sarda Sahney During Pennsylvanian times, 310 million years ago, North America and Europe lay on the equator and were covered by steamy tropical rainforests inhabited by a bizarre array of animals. The Cumberland basin of Atlantic Canada contains one of the most complete and fossilliferous successions of this age anywhere in the world. Massive fossil collections have accumulated over the past 170 years through the meticulous work of Lyell, Dawson, Stopes, Bell, and many others, yet no synthesis of this fossil record currently exists. Sarah is building a database of published fossil assemblages in their sedimentary facies context from more than 200 localities across the basin. Email: sk6660@bristol.ac.uk
Lynne Toland, MSci 2007 - The Great American Biotic Interchange, saber-toothmarsupials and alpha diversity
		Supervisors: Sarda Sahney and Michael Benton Three million years ago the formation of the Panama land bridge initiated The Great American Biotic Interchange, which dramatically changed the composition of South American mammal communities. Invading placental mammals from North American replaced many marsupial species in South America. Through close examination we can see that the invading placentals from North American and the native South American marsupials had extraordinarily similar morphology. For example, the marsupial Thylacosmilus and the placental saber-tooth cat, Smilodon , were both large mammalian hunters with sleek, strong bodies and several highly specialized, convergent adaptations such as ‘saber-teeth’. As a result they filled similar ecological niches and Smilodon replaced Thylacosmilus in the same way many other placentals replaced similar marsupials. Lynne is studying alpha (community) diversity to determine how this replacement occurred. Key questions she is considering include: Was the replacement rapid or gradual? Was it due to competition or was it passive? How did communities change during the megafaunal extinction in the Pleistocene? Email: lt3539@bristol.ac.uk
Phil Jardine, MSc 2006 - The evolution of grassland communities in North and South America
		Supervisors: Sarda Sahney and Michael Benton Changing climate in the Oligocene and Miocene was instrumental in the replacement of forests by grasslands in many regions. Habitats for browsers, who primarily feed on woody plants, were lost. However, the new ‘grazers’ quickly populated the grasslands; this including rodents, rabbits and ungulates (hoofed animals such as horses, deer, goats, rhinos and elephants). Phil tracked grassland community evolution in North and South America. He focused on changing community structure and found a large degree of congruence with global diversity patterns. Currently: PhD at the University of Bimingham Email: pej083@bham.ac.uk
John Orcutt, MSc 2006 - Tracking tetrapod community diversity across a proposed Jurassic-Cretaceous mass extinction
		Supervisors: Sarda Sahney, Graeme Lloyd, and Michael Benton Mass extinctions have dramatically reshaped life on Earth. In addition to eradicating many land and sea creatures, mass extinctions open up ecological niches, permitting surviving species to diversify and explore new modes of life. John examined the diversity of vertebrate communities through the Jurassic-Cretaceous boundary and found evidence supporting a mass extinction event at this time. Currently: PhD at the University of Oregon Email:jorcutt@uoregon.edu

Palaeobiology and Biodiversity Research Group, Department of Earth Sciences, University of Bristol

Updated 2007.02.01