Data, metrics, and methods for arthropod and fungal herbivory at the dawn of angiosperm diversification: The Rose Creek plant assemblage of Nebraska, U.S.A.
This is the supplementary material referred to the Data in Brief text, and the Data in Brief text is associated with our manuscript "Arthropod and fungal herbivory at the dawn of angiosperm diversification: The Rose Creek plant assemblage of Nebraska, U.S.A.". Appendices of the Supporting Information furnish data, extended documentation, and a review of the relevant literature that bolster various aspects of the plant–arthropod interactions of the Rose Creek locality presented in the main text and linked Data in Brief. Appendices S1 to S3 provide ancillary accounts at a global level of plant-organismic associations present during the Early Cretaceous relevant to the Rose Creek locality. Appendix S4 displays the botanical context of the Rose Creek locality, whereas Appendices S5–S10 discuss the procedures for processing and databasing the Rose Creek plant assemblage, including criteria for establishing plant taxa and distinguishing herbivory from detritivory, rarefaction analyses of the plant specimens and damage types (DTs), and a recent study of arthropod damage on Rose Creek flowers. The rarefaction analyses of plant specimens and damage types versus surface areas (Appendix S9) indicate adequate sampling. Appendices S11, S12 and S16 supply the basic data of functional feeding groups, raw plant damage, and DT host-plant specificization. Photographic images represent continuation of Figures 2 to 6 of the main text, presented here as Appendix S13 with figures S1–S15 that documents photographically the extraordinary breadth of the functional feeding groups (FFGs) and damage types (DTs). Appendix S14 provides brief discussions of the fossil histories of the 11 functional feeding groups occurring at Rose Creek. The DT host-plant specialization assignments for each damage type (DT) are listed in Appendix S15. The composition of the plant taxa included in the nonmetric multidimension analysis (Fig. 11) is provided in Appendix S17. Descriptions and data are presented for the 14 new Rose Creek DTs, representing six FFGs, in Appendix S18. These new DTs will be included in forthcoming Version 4 of the Guide to Insect (and Other) Damage Types on Compressed Plant Fossils (Labandeira et al., 2007). Appendices S19–S25 address in greater detail issues broached in the Discussion section of the manuscript.
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The data consists of two complimentary approaches toward assessing arthropod herbivory. First, a descriptive analysis categorizes the affinities and diversity of the plant taxa and describes the spectrum of functional feeding groups (FFGs) and damage types (DTs) on leaves and other organs of the plant groups. Second, quantitative metrics for the entire plant assemblage details the two basic approaches of herbivory richness and herbivory intensity. Herbivory richness is evaluated by the three metrics of DT richness, component community structure (a composite measure), and the degree of herbivory specialization. By contrast, herbivory intensity is determined by the three metrics of DT frequency, herbivorized surface area, and feeding event occurrences. For herbivore damage on plant specimens, data capture was done visually with assistance of relevant plant literature for Cretaceous plants , sources for DT determinations [3–5], and experience of the coauthors. Light microscopy was used for examination and photographic documentation. Photography was done with a Canon 50D camera and a Canon EF-S60 mm f/2.8 macro lens, Nikon SMZ 25 microscope with a Nikon DS-Ri 2 digital camera system, Digital imaging and processing was based on Image J capture of specimen data, and Adobe® Illustrator, Drawer, and Photoshop software. Data analyses was implemented by R and Excel. All recognizable plant specimens (leaves, pinnules, axes, roots, reproductive material) greater in area than about 0.25 cm2 were identified. When possible, herbivory data were collected, including DT richness, component community structure for the three most herbivorized taxa, herbivore specialization values, DT frequency, total and herbivorized surface area, and feeding event occurrences. All data were entered into excel data files. Comparisons were made between the herbivorized surface area (herbivory index) of the Rose Creek plant assemblage and its constituent major clades and species/morphotypes versus other analogous taxa and plant assemblages from the fossil and modern records. The stoichiometry of the major functional feeding groups – a composite ectophytic feeding, piercing and sucking, mining, and galling – was compared for the three most herbivorized Rose Creek taxa and five modern, well documented taxa. Relevant sources [1–5] informed many of these decisions.