Dr Uwe Balthasar
Lecturer in Palaeontology
School of Geography, Earth and Environmental Sciences (Faculty of Science and Engineering)
Phanerozoic evolution of aragonite and calcite biomineralisation in the context of ocean chemistry
The dominance of aragonite and calcite has fluctuated throughout the Phanerozoic in inorganic precipitates such as ooids or cements. I am interested in understanding how these changes impacted on the evolution of calcifying organisms. To do this I combine inorganic CaCO3 precipitation experiments designed to better interpret the distribution of non-biogenic aragonite and calcite in the rock record with the careful examination of calcareous fossils of uncertain original mineralogy. Ultimately, this work aims at providing an environmental context in which the evolution of biogenic calcification can be assesed in time and space.
Origins of brachiopods and their evolution of biomineralisation
Brachiopods are one of the first animal phyla to appear in the course of the Cambrian explosion and among the most versatile groups with respect to biomineralisation including groups that evolved the ability to secrete apatite, aragonite, calcite, opaline silica, and possibly even the ability to agglutinate sand grains. All of these different biomineralisation strategies of brachiopods evolved during the Cambrian - Ordovician, whereas no further innovation occured in this respect thoughout the rest of the Phanerozoic. What was driving this burst of innovation in biomineralisation?