“…Among global paleogeographic reconstructions proposed for the early Cambrian (e.g., roZ A n o v , 1984; Z o n e n s h A i n , KuZmin, & Kononov, 1985;scoTese & mcKerroW, 1990;courJAulT-rADé, Debrenne, & gAnDin, 1992;KirschvinK, 1992;mcKerroW, scoTese, & brAsier, 1992;sToreY, 1993;DAlZiel, DAllA sAlDA, & gAhAgAn, 1994;TorsviK & others, 1996;KirschvinK, riPPerDAn, & evAns, 1997;liebermAn, 1997;smiTh, 2001;golonKA, 2002;meerT & liebermAn, 2008;rino & others, 2008), those that best fit the archaeocyathan distribution portray a postsupercontinental world (Rodinian or Pannotian) with the major epicontinental basins within the intertropical zone. The inferred pathways of archaeocyathan migration, coupled with the use of the Jaccard similarity coefficient applied to the total local Cambrian faunas, calculated for NemakitDaldynian-early Tommotian, early Atdabanian, and late Atdabanian-Botoman intervals, support those paleogeographic reconstructions suggesting the existence of East and West Gondwana in the early Cambrian, as proposed by moores (1991) and KirschvinK (1992), with their subsequent collision by the late early Cambrian (cAWooD, 2005;PAulsen & others, 2007), the rifting of Laurentia from the AustralianAntarctic margin, and the drift of suspect terranes toward Siberia (Debrenne, mAiDAnsKAYA, & ZhurAvlev, 1999).…”