1. Department of Ecology and Evolutionary Biology; University of Toronto; 25 Willcocks Street Toronto Ontario M5S 3B2 Canada
2. Department of earth Sciences; University of Cambridge; Downing Street Cambridge CB2 3EQ United Kingdom
3. Department of Earth Sciences (Palaeobiology); University of Uppsala; Villavägen 16 SE-752 36 Uppsala Sweden
4. Department of Organismal Biology (Subdepartment of Evolution and Development); Norbyvägen 18A SE-752 36 Uppsala Sweden
5. Department of Natural History; Royal Ontario Museum; 100 Queen's Park Toronto Ontario Canada M5S 2C6