1. 1Instituto de Geociencias (CSIC-UCM), Dr. Severo Ochoa 7, 28040 Madrid, Spain
2. 2New Brunswick Department of Natural Resources and Energy Development, Geological Surveys Branch, Box 5040, Sussex, New Brunswick E4E 5L2, Canada
3. 3Department of Earth & Environmental Science, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada
4. 4Área de Paleontología, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain