Supporting Information Na and Kiessling 10.1073/pnas.1424985112 SI Materials and Methods the concept of the late Ediacaran supercontinent Pannotia (9) as Stratigraphic Reassignment. The downloaded dataset from the implemented in Scotese’s (10) maps is not universally accepted. Paleobiology Database (PaleobioDB, paleobiodb.org) contains However, the most recent revision of Ediacaran-Cambrian stratigraphic information on every collection. However, the in- plate tectonics agrees with our basic assumption that a transient formation is often imprecise (e.g., epoch rather than stage level) Pannotia supercontinent existed and that the Ediacaran (in the and inaccurate. The main problem is the use of obsolete strati- north) to Early Cambrian (in the south) saw its breakup, which is graphic terms such as the traditional Siberian stages for the related to the Cambrian radiation (11). Pannotia was probably former Early Cambrian and the Laurentian subdivision of the short-lived and, thus, difficult to establish. The largest part of Upper Cambrian in the PaleobioDB. Given that Ediacaran- Pannotia is Gondwana, which assembled following the closure of Cambrian stratigraphy is still in a state of flux, we vetted man- three ancient paleo-oceans during the Ediacaran (12–14). The ually the stratigraphy of all collections in the dataset with the aid core of Gondwana consisted mainly of Australia, India, Africa, of published stratigraphic correlations among Siberia, south Antarctica, and South America, with numerous microcontinents China, Australia, Laurentia, and Baltica (1–8). Collections in the at its margins (i.e., South China, Avalonia, Cadomina, Iran, and dataset were reassigned according to the biostratigraphic corre- Turkey) (15). Although the precise position of individual tectonic lation chart defined in this study (Fig. S7). Of the 7,117 fossil collections in the downloaded dataset, only 4,443 could be as- plates or cratonic blocks within Pannotia is debated, it is known signed to one of 43 biozones, whereas 6,869 could be assigned to that Laurentia was located between East and West Gondwana at a stage. We therefore chose to use the coarser 14-stage separa- the end of the Ediacaran (9, 16). The breakup of Pannotia is tion to maximize sample sizes for time series analyses. constrained by the opening of the Iapetus Ocean (11, 17) that also marked the separation of Laurentia and Baltica (18), and Early Cambrian Reconstructions. Plate-tectonic reconstructions for the separation of Laurentia and Siberia close to Precambrian- the Cambrian are still poorly constrained and controversial. Even Cambrian boundary (19). 1. Geyer G, Shergold J (2000) The quest for internationally recognized divisions of 10. Scotese CR (2001) Paleomap Project. Available at www.scotese.com. Accessed July 17, Cambrian time. Episodes 23(3):188–195. 2001. 2. Peng S, Babcock L, Cooper R (2012) The Geologic Time Scale, eds Gradstein FM, 11. Dalziel IWD (2014) Cambrian transgression and radiation linked to an Iapetus-Pacific Ogg JG, Schmitz MD, Ogg GM (Elsevier, Amsterdam), pp 437–488. oceanic connection? Geology 42(11):979–982. 3. Landing E, Geyer G, Brasier MD, Bowring SA (2013) Cambrian Evolutionary Radiation: 12. Meert JG (2003) A synopsis of events related to the assembly of eastern Gondwana. Context, correlation, and chronostratigraphy - Overcoming deficiencies of the first Tectonophysics 362(1-4):1–40. appearance datum (FAD) concept. Earth Sci Rev 123:133–172. 13. Collins AS (2006) Madagascar and the amalgamation of Central Gondwana. Gond- 4. Steiner M, Li GX, Qian Y, Zhu MY, Erdtmann BD (2007) Neoproterozoic to early wana Res 9(1-2):3–16. Cambrian small shelly fossil assemblages and a revised biostratigraphic correlation of 14. Mikhalsky EV, Sheraton JW, Hahne K (2006) Charnockite composition in relation to the Yangtze Platform (China). Palaeogeogr Palaeoclim Palaeocl 254(1-2):67–99. the tectonic evolution of East Antarctica. Gondwana Res 9(4):379–397. 5. Zhu MY, Li GX, Zhang JM, Steiner M (2001) Early Cambrian stratigraphy of east 15. Golonka J (2002) Phanerozoic Reef Patterns (Soc Sediment Geol, Tulsa), pp 21–75. Yunnan, southwestern China: A synthesis. Acta Palaeontologica Sin 40:4–29. 16. Hoffman PF (1991) Did the breakout of laurentia turn gondwanaland inside-out? 6. Babcock L, Robison R, Shanchi P (2011) Cambrian stage and series nomenclature of Science 252(5011):1409–1412. Laurentia and the developing global chronostratigraphic scale. Mus North Ariz Bull 17. Condie KC (2003) Supercontinents, superplumes and continental growth: The Neo- 67:12–26. proterozoic record. Geol Soc Lond Spec Publ 206(1):1–21. 7. Kruse PD, Jago JB, Laurie JR (2009) Recent developments in Australian Cambrian 18. Torsvik T, et al. (1996) Continental break-up and collision in the Neoproterozoic and biostratigraphy. J Stratigr 33(1):35–47. Palaeozoic—a tale of Baltica and Laurentia. Earth Sci Rev 40(3):229–258. 8. Young GC, Laurie JR (1996) An Australian Phanerozoic Timescale (Oxford Univ Press, 19. Pelechaty SM (1996) Stratigraphic evidence for the Siberia-Laurentia connection and Melbourne). early Cambrian rifting. Geology 24(8):719–722. 9. Dalziel IWD (1997) Neoproterozoic-Paleozoic geography and tectonics: Review, hy- 20. Narbonne G, et al. (2012) The Geologic Time Scale, eds Gradstein FM, Ogg JG, pothesis, environmental speculation. Geol Soc Am Bull 109(1):16–42. Schmitz MD, Ogg GM (Elsevier, Amsterdam), pp 413–435. Na and Kiessling www.pnas.org/cgi/content/short/1424985112 1of7 Fig. S1. Alpha diversity measured by the Shannon index (H’) of quantitative collections comprising at least 80 specimens per collection. Individual estimates are represented by symbols separated by substrate lithology. These estimates exclude values of less than 0.2 to reduce the bias from extreme habitats. The blue line connects median values. Fig. S2. Spearman rank correlations between gamma-alpha diversity and gamma-beta diversity measured within a moving window of five successive bins. Values are plotted in the middle of window. The correlation of gamma and beta diversity is high throughout the Cambrian and often significant, but thereis no significant correlation between gamma and alpha diversity. Empty blue squares denote correlations with a P < 0.1 and solid blue squares P < 0.05. Na and Kiessling www.pnas.org/cgi/content/short/1424985112 2of7 Fig. S3. Bray-Curtis dissimilarity in assemblage composition among geographic grids in three intervals of paleogeographic distance (A) and among envi- ronmental categories in tropical areas (B). Only grids/categories with at least 10 occurrences were considered. Vertical bars indicate SEs. (B) Brown line indicates one change and blue line two changes in environmental categories, which are carbonate/siliciclastic lithology and shallow-water/deep-water bathymetry. Na and Kiessling www.pnas.org/cgi/content/short/1424985112 3of7 Fig. S4. Geographic representation of dissimilarity among geographic grids within distance from 2,000 km to 4,000 km plotted on paleogeographic maps for Fortunian (A), Stage 2 (B), and Stage 3 (C) in the Cambrian. Lines are only shown between grids with at least 10 occurrences. The thickness of connecting lines is proportional to the Bray–Curtis dissimilarity between grids. Maps are based on Scotese (10) and show his 540-Ma (A and B) and 520 Ma (C) reconstructions. BAL, Baltica; EGOND, East Gondwana; LAU, Laurentia; SIB, Siberia; WGOND, West Gondwana. Fig. S5. Trajectories of global beta (Fig. 2) minus within-Gondwana beta. Beta diversity within Gondwana from the Ediacaran to the earliest Ordovician based on unweighted by-list subsampling of 13 collections per stage. Na and Kiessling www.pnas.org/cgi/content/short/1424985112 4of7 Fig. S6. Sampling-standardized genus-level diversity (sampled-in-bin) based on shareholder quorum subsampling with 70% frequency coverage per stage based on traditional timescale (A). Note log scale of y axis. Alpha diversity and beta diversity through Ediacaran-Cambrian times based on unweighted by-list subsampling of 134 collections per stage (B). Error bars are SDs of 100 subsampling trials. At, Atdabanian (520-516 Ma); Bo, Botomian (516-510 Ma); M. Camb, Middle Cambrian (510-501 Ma); Ma, million years ago. N-D, Nemakit-Daldynian (542-530 Ma); Tomm, Tommotian (530-520 Ma); U. Camb, Upper Cambrian (501-490 Ma). Na and Kiessling www.pnas.org/cgi/content/short/1424985112 5of7 Fig. S7. Biostratigraphic correlation chart used to assign collections in the Paleobiology Database to 14 international stage-level intervals. The biostratigraphic separation for the late Ediacaran period is based on ref. 20. The correlation part for the Cambrian is based on body fossil zonal schemes of principal regions. Siberia, refs. 1–3. South China, refs. 4, 5 for SSF zones and ref. 2 for trilobite zones. Laurentia, ref. 6. Australia, refs. 7, 8. Baltica, refs. 1, 3. Na and Kiessling www.pnas.org/cgi/content/short/1424985112 6of7 Table S1. Linear regressions between Cambrian geodisparity and paleogeographic distance in three intervals of great circle distance <2,000 km 2,000–4,000 km >4,000 km Stage Int Sl ρ Int Sl ρ Int Sl ρ Fortunian −0.67 0.05 0.03 −5.72 0.66 0.55* −0.9 0.06 0.27 Stage 2 −1.19 0.12 0.13 −4.67 0.56 0.62* −0.5 0.04 0.13* Stage 3 −0.76 0.09 0.18 * −1.57 0.19 0.28*** −0.1 0 −0.01 Stage 4 −0.75 0.08 0.1 −1.78 0.21 0.09 −0.3 0.02 0.09* Stage 5 −0.47 0.04 0.11 −0.23 0.01 0.07 −0.2 0.02 −0.03 Drumian −1.08 0.13 0.22 −0.5 0.05 0.12 −0.1 0 0 Guzhangian −1.03 0.12 0.26* −0.63 0.07 0.09 −0.2 0.02 0.04 Paibian −1.78 0.23 0.43* 0 −0.01 −0.05 −0.1 0 −0.03 Jiangshanian −1.17 0.14 0.14 −1.38 0.16 0.23 −0.7 0.06 0.12 Stage 10 −0.85 0.1 0.14 −0.34 0.04 0.16 −0.2 0.02 0.02 Int, intercept; ρ, Spearman’s rho; Sl, slope.