Safety factors of M. extradentata and S. inexpectata with claws and without claws on different substrates. (A) Pull-off force measurement of M. extradentata with and without claws. (B) Pull-off force measurement of S. inexpectata with and without claws. (C) Traction force measurement of M. extradentata with and without claws. (D) Traction force measurement of S. inexpectata with and without claws. (E) Pull-off force measurement of both species without claws. (F) Traction force measurement of both species without claws. Groups which do not differ significantly from each other are marked n.s. and groups which differ with a significance of p > 0.05 are marked * for each substrate. Kruskal–Wallis one-way ANOVA on ranks ((A): H = 287.832, (B): H = 276.410, (C): H = 179.328, (D): H =171.182, (E): H = 126.899, (F): H = 100.812; p ≤ 0.001, d.f. = 9, Nwithout_claws = 10, Nwith_claws = 15) and Dunn’s method (A–D; p < 0.05) or Turkey’s test (E,F; p < 0.05). The boxes indicate 25th and 75th percentiles, whiskers define the 10th and 90th percentiles and the line within the boxes represents the median. Outliers are shown as individual points.