Chelicerata Heymons, 1901 †Trigonotarbida Petrunkevitch, 1949 Family †Anthracosironidae Pocock, 1903 1 Genus †Anthracosiro Pocock, 1903 2 Genus †Arianrhoda Dunlop & Selden, 2004 3 Genus †Vratislavia Fritsch, 1904