PERSISTENT PREDATOR-PREY DYNAMICS REVEALED BY MASS EXTINCTION.

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1 1 Supporting Information Appendix for PERSISTENT PREDATOR-PREY DYNAMICS REVEALED BY MASS EXTINCTION. Lauren Cole Sallan, Thomas W. Kammer, William I. Ausich, Lewis A. Cook 1

2 2 Illustration - A Viséan Euramerican shallow marine ecosystem. Crinoids include the camerates Dizygocrinus (under attack, bottom center, left) and the spiny Dorycrinus (bottom center, right), and the advanced cladids Decadocrinus (bottom left) and Abrotocrinus (bottom right). Vertebrates include the cochliodont Deltoptychius (bottom center), the petalodont Janassa (left of center, ventral view), the chondrenchelyiform Chondrenchelys (far left), and the actinopterygian Amphicentrum (upper right). (Robert Nicholls) Table of Contents. I. Supporting Methods and Discussion 3 II. Supporting References 5 III. Supporting Tables 7 Table S1. Global Devonian-Mississippian genera per stage. 7 Table S2. Miss. North America and British Isles genera per time bin. 8 Table S3. Correlation values for Dev.-Miss. groups. 9 Table S4. Correlation values for Miss. N. Amer. and Brit. Is. groups. 10 2

3 3 I. Supporting Methods and Discussion Correlations between fish and camerate diversity presented here are likely valid. The runs test revealed the diversity curves for Mississippian durophagous fishes (P = 0.01) to be significantly different from random walks, whereas the advanced cladid pattern was indeed random despite the early increase and loss of camerates (P = 0.75). As noted in the text, the post-hangenberg diversity curve for camerates fell just above significance (P = 0.07) at α This was probably due to their change in direction at the Tournaisian-Visean boundary, leading to three runs in a short time series. The decline phase could not be tested directly due to the presence of less than ten points. Other observations suggest this decline is real, including the gradual loss of complex camerates in the later Mississippian, high extinction rates among camerates of this interval, the global turnover of the crinoid evolutionary fauna, and the extinction of the group by the end of the Paleozoic (1, 2). Other aspects of the data render spurious concordance unlikely. Most Mississippian durophagous fish remains (diagnostic teeth) and crinoid remains are found in the same deposits around North America and Britain, which makes outcrop bias unlikely. Crushing shark teeth and crinoid fossils are therefore likely to have similar taphonomy, eliminating the effects of taphonomic bias as well. As explained in the text, there is direct fossil evidence for predatory interactions between crinoids and durophagous fishes in the Devonian and Mississippian, and for a greater number of crushing fishes in the latter stage (3-5). In addition, negative correlations, such as those characterizing the relationship between well-sampled taxa in the same deposits, such as durophages and camerates in the post-tournaisian, cannot be explained by rock 3

4 4 volume or other sampling problems that are often the source of spurious correlations. Finally, if a third phenomenon were driving the apparent interaction between Mississippian fish and camerates, we would expect to see it show up in the pattern for advanced cladids. However, the diversity of advanced cladids in the Mississippian represents a random walk, one not significantly correlated with either camerates or predatory vertebrates (Fig. 2). The interaction provides an explanation for the radical increase in crushing durophages and appearance of new, smaller, benthic body forms among the Tournaisian vertebrates (3). These had previously been ascribed to environmental changes or the appearance of unknown prey that can now be named. Significance of correlation (P) for all time series was based on a two-tailed t-test (α 0.05) (Tables S3 and S4) (6). This was done for both the raw data and first differences (FD). First differencing is a method of removing the effects of autocorrelation by only comparing changes between bins. This technique supported many of the main correlations found using raw diversity as pointed out the in the text. For the Mississippian curves, the correlations from FD indicated the same relationships as the raw data, with significance for the interval marking the decline of camerates (Table S4). As expected, especially when there are few points to test or when diversity is relatively low, FD results were more conservative than for raw counts (7). In such a case, the FD test confirmed the general interaction is enough. This also holds for the FD correlation values for the Givetian-Serpukhovian dataset, which were based on fewer points than the Mississippian series. Considering the limited power of these analyses, significant correlations must be representative of very strong signal. 4

5 5 II. Supporting References 1. Simpson C (2010) Species selection and driven mechanisms jointly generate a large-scale morphological trend in monobathrid camerates. Paleobiology 36: Ausich WI, Kammer TW, Baumiller TK (1994) Demise of the middle Paleozoic crinoid fauna: a single extinction event or rapid faunal turnover? Paleobiology 20: Sallan LC, Coates MI (2010) End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates. Proc Natl Acad Sci USA 107: Moy-Thomas JA, Miles RS (1971) Palaeozoic Fishes (Saunders, Philadelphia). 5. Zangerl R, Richardson, ES (1963) The paleoecological history of two Pennsylvanian black shales. Fieldiana 4: Davis, J. C. Statistics and Data Analysis in Geology (Wiley, 2002). 7. Huntley JW, Kowalewski M (2007) Strong coupling of predatory intensity and diversity in the Phanerozoic fossil record. Proc Natl Acad Sci USA 104: Kammer TW, Ausich WI (2006) The age of crinoids : A Mississippian biodiversity spike coincident with widespread carbonate ramps. Palaios 21: Waters JA. Webster GD (2009) in Devonian Change: Case Studies in Palaeogeography and Palaeoecology, ed. Königshof P (Geol Soc Spec. Publ 314, London), pp

6 6 10. Gradstein, F., Ogg, J. & Smith, A. (2004) A Geologic Time Scale (Cambridge Univ Press, Cambridge, U.K.). 11. Ausich WI, Kammer TW (2006) Stratigraphical and geographical distribution of Lower Carboniferous Crinoidea from England and Wales. Proc Yorkshire Geol Soc 56: Kammer TW, Ausich WI (2007) Stratigraphical and geographical distribution of Mississippian Crinoidea from Scotland. Earth Environ Trans. R Soc Edinburgh 98: Cook LA (2010) Systematics and evolutionary paleoecology of crinoids from the St. Louis Limestone (Mississippian, Meramecian) of the Illinois Basin. PhD Thesis (West Virginia University), 180 pp. 14. Ausich WI, Kammer TK (2008) Generic concepts in the Amphoracrinidae Bather, 1899 (Class Crinoidea) and evaluation of generic assignments of North American species. J Paleontol 82: Ausich WI, Kammer TK (2009) Generic concepts in the Platycrinitidae Austin and Austin, 1842 (Class Crinoidea). J Paleontol 83: Ausich WI, Kammer TK (2010) Generic concepts in the Batocrinidae Wachsmuth and Springer, 1881 (Class Crinoidea). J Paleontol 84:

7 7 III. Supporting Tables Table S1. Global Devonian-Mississippian genera per stage. This table contains global data on genera per stage for crinoid clades and gnathostome durophages, using the range-through method (crinoid data compiled by T.W.K, and W.I.A from 8-9, durophages are new compilation by L.C.S., based on 3) (Fig. 1). Stages are from the Middle Devonian Givetian to the Late Mississippian Serpukhovian. Devonian durophages are placoderms and sarcopterygians (Dipnoi), whereas Mississippian durophages are actinopterygians and chondrichthyans. Viséan maximum for total crinoids reflects the longer time period for this stage (19 million years) versus the shorter Tournaisian (14 million years) (10, with peak diversity actually reached in Tournaisian 3 (Table S2). Givetian Frasnian Famenn. Tour. Viséan Serp. Crinoids Camerates Advanced Cladids Primitive Cladids Flexibles Disparids Total Crinoids Fishes Placoderms Dipnoi Devonian Duros Actinopterygians Chondrichthyans Mississippian Duros Total Durophages

8 8 Table S2. Mississippian North America and British Isles genera per time bin. Generic counts for Missisippian crinoids and marine gnathostome durophages from North America and the British Isles were obtained using the range-through method (new compilations by the authors, including crinoid data from 11-16). Taxa are binned according to the time intervals used by Ausich and Kammer (11) and Kammer and Ausich (12). Tour1 Tour2 Tour3 Tour4 Visé1 Visé2 Visé3 Visé4 Visé5 Serp1 Serp2 Crinoids Camerates Advanced Cladids Primitive Cladids Flexibles Disparids Total Crinoids Fishes Orodonts Eugeneodonts Psammodonts Helodonts Cochliodonts Petalodonts Chondrenchelyiformes Actinopterygians Total Durophages

9 9 Table S3. Correlation values (r and P) for Devonian-Mississippian groups. Givetian- Serpukhovian crinoid groups were compared to Devonian marine gnathostome durophages (placoderms and sarcopterygians) and Mississippian marine gnathostome durophages (actinopterygians and chondrichthyans) (Fig. 1, Table S1). Significance of correlation (P) based on two-tailed t-test (6). Significant correlations are in bold (α 0.05). Devonian Durophages Mississippian Durophages Total Crinoids, Givetian-Serp. Total Crinoids, Givetian-Visé. Camerates, Givetian-Serp. Advanced Cladids, Givetian-Serp. Raw Data First Differences Raw Data First Differences -0.82, , , , , , , , , , , , , , , ,

10 10 Table S4. Correlation values (r and P) for Mississippian North America and British Isles groups. Marine durophagous gnathostomes and camerate and advanced cladid crinoids were compared for different combinations of time intervals (Fig. 2, Table S2). Significance of correlation (P) based on two-tailed t-test (6). Significant correlations are in bold (α 0.05). Camerates vs Miss. Durophages Advanced Cladids vs Miss. Durophages Raw Data First Differences Raw Data First Differences Tour1-Tour4 0.96, , , , 0.94 Tour1-Serp1-0.42, , , , 0.72 Tour1-Serp2-0.51, , , , 0.87 Tour4-Serp1-0.84, , , , 0.88 Tour4-Serp2-0.86, , , , 0.77 Visé1-Serp1-0.95, , , , 0.69 Visé1-Serp2-0.94, , , ,