[1] Univ Nacl Autonoma Mexico, Inst Biol, Mexico City 04510, DF, Mexico
[2] Slovak Acad Sci, Inst Geol, Bratislava 84005 45, Slovakia
[3] Russian Acad Sci, Arthropoda Lab, Inst Paleontol, Moscow 117868, Russia
[4] Univ Nacl Autonoma Mexico, Inst Geol, Mexico City 04510, DF, Mexico
[5] SEP Coahuila Museo Desierto, Coordinac Paleontol, Saltillo 25000, Coahuila, Mexico