Comparison of size frequency distributions for drilled and undrilled specimens.

Specimen size estimated by maximum tube width [mm]. Basic descriptive statistics are reported here separately for drilled and undrilled specimens grouped by sample and for the pooled data (the last two rows). Non-parametric statistical tests for differences in central tendency (Wilcoxon 2-Sample Test) and shape of distributions (Kolmogorov-Smirnov Test) are also reported.aTests significant without Bonferroni correction at the assumed α = 0.05.bTests significant with Bonferroni corrections (α/number of tests; α = 0.005).