2.2 | Behavioral and morphological character scoring
By combining a semi-exhaustive literature review with exemplar
cross-checking, we then scored two behavioral characters and 55
morphological characters (see Appendix B for character information,
Wilson et al., 2022a for character matrix, dataset references and
exemplar information) for all 110 genera in the supertree. Behavioral
characters relate to retreat construction method and retreat-entrance
type and are defined below. To score these characters we made extensive
use of Coyle (1986), which remains the most thorough review of
mygalomorph burrowing behavior to date, and then cross-checked this with
taxon-specific literature (Wilson et al., 2022a). The 55 morphological
characters are all somatic, macro-morphological features (Appendix B).
These were scored exclusively from adult females because adult male
morphology is at least partially adapted for the terrestrial dispersal
phase that they undergo, whereas female morphology is more
representative of the general morphology of the species (in that
juveniles of both sexes resemble adult females) and is presumably
adapted to the sedentary lifestyle of the species. Most of our
morphological characters correspond closely with those scored in
previous morphological analyses of the Mygalomorphae (Bond et al., 2012;
Bond & Opell, 2002; Goloboff, 1993, 1995; Raven, 1985), but we have
restructured characters following the logic for character/state
structure outlined by Sereno (2007) and modified character and state
definitions to decrease ambiguity. These previous studies were used
extensively during character scoring, with taxon-specific literature and
exemplar specimens then cross-checked when available (Wilson et al.,
2022a).
BEHAVIORAL CHARACTERS
Retreat construction method: Opportunist – taxa that
usually inhabit existing spaces (e.g., cracks and overhangs in
embankments, spaces under rocks and within logs) rather than
digging/constructing a retreat = 0; obligate burrower – taxa
that usually dig their own tubular burrow directly into the substrate
= 1; nest-builder – taxa that construct short, silken nests,
which are attached directly to the substrate (often on trees, cave
walls, or sometimes directly to the ground) = 2.
Retreat entrance, type: web – extensive use of silk
outside the entrance to the retreat to form a flat sheet, a funnel, or
a space/curtain web = 0; open – an unmodified, circular
opening to the retreat (which may temporarily be covered with silk or
soil by the spider) = 1; turret – an entrance that is open,
but modified to extend from the substrate through the use of silk
and/or soil = 2; collar – an entrance that is closable through
the use of a silken collar that collapses inward = 3; trapdoor– an entrance that is closed with a ‘door’ constituting an
asymmetrical extension of the burrow lining (often mixed with soil
and/or humus fragments), allowing the demarcation of one side of the
burrow as the ‘hinge’ side = 4; purse – an extension of the
burrow lining that lies along the substrate or is attached vertically
to a surface, is rough and camouflaged, through which the spider
ambushes prey = 5.