1. 503 Coxheath Road, Sydney, Nova Scotia , Canada
2. Centre of Palaeobiodiversity, West Bohemian Museum in Pilsen , Kopeckého sady 2, Pilsen 30100, Czech Republic
3. State Key Laboratory of Palaeobiology and Stratigraphy , Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences , Nanjing 210008 , China