This is a past event
Please join us for a research seminar given by Dr. Ken McNamara (University of Cambridge) on, “Effects of Environmental Changes on the Evolution and Extinction of Late Devonian trilobites from the northern Canning Basin, Western Australia”. The seminar will take place at 1PM on Thursday, 13th October in Meston Lecture Theatre 2. All are welcome to attend.
Abstract
A spectacular fossil reef system fringes the Kimberley Block in northern Western Australia. These 370 million year old Late Devonian rocks document one of the 5 mass extinctions that have punctuated life in the last half a billion years. Amongst the fossil biota is a rich trilobite fauna. Over the last 10 years, with my colleague Raimund Feist, I have described 49 species of which 41 are new.
Evolutionary trends in many of the lineages of the trilobites prior to the mass extinction are dominated by reduction in body size and eye size, both arising from developmental changes in successive species. These are thought to reflect selection for forms adapted to low nutrient conditions. Although recording no sedimentological signature, the fauna was strongly affected by the two globally recognized extinction events that together comprise the Late Devonian mass extinction, the so-called Kellwasser Events. The mass extinction was particularly severe on trilobites. These two intensive extinction episodes may reflect periodic massive inputs of nutrients from the terrestrial into the shallow marine environment.
- Speaker
- Dr Ken McNamara
- Venue
- Meston Lecture Theatre 2