Supplemental Figure 1. Ace character state reconstruction of Fernandez et al. 2018 data set
Preferred 'ace' ancestral state reconstruction of web types using Fernandez et al. 2018 coding scheme (Table S1) but including Pararchaea. Optimization correctly shows four, rather than three independent origins of the orb web.
Supplemental Figure 2. Optimization of web presence/absence
Optimizing web presence/absence shows that webs are ancestral with ~6 subsequent losses (ARD AICc = 135.7375). Corresponds to manuscript figure 1A but includes taxon names.
Supplemental Figure 3. Optimization of Fernandez et al. 2018 data set with non foraging silk-lined burrows and no foraging webs treated as a single character
Optimization of Fernandez et al. 2018 data set with non foraging silk-lined burrows and no foraging webs treated as a single character; spiders are unequivocally primitively webless under this scenario based on an ER model (AICc = 375.491).
Supplemental Figure 4. Ancestral state reconstruction of foraging webs - character states corrected and no foraging webs treated as missing/inapplicable
Preferred ancestral state reconstruction of web types using a corrected character coding scheme (Table S1, modified from Blackledge et al. 2009), the ER model in corHMM, and with webless taxa treated as inapplicable (-); tree modified as ultrametric; AICc = 222.8629. This hypothesis implies a single ancient origin of the orb web; spiders primitively use webs for foraging.
Supplemental Figure 5. Ancestral state reconstruction of web types using Fernandez et al. 2018 character uncorrected scoring scheme with no foraging webs scored as missing/inapplicable
An analysis of F&al’s matrix using corHMM with an ER model that includes Pararchaea, only further modified by changing “no foraging web” to missing/inapplicable optimizes irregular ground and aerial sheets as the ancestral web architectures with four independent origins of the orb web.