Table 1 Comparative overview of principal morphological and structural scale characteristics.

(A) Scales of scale-bearing hexapod lineages examined in this study (for details, see the Supplementary Materials). (B) Distinctive Rhaetian-Hettangian lepidopteran scale types. “-”, absence of a trait; “?”, uncertainty regarding presence/absence or interpretation of a trait.

GroupApical marginCross ridgesMicroribsStructurePerforationsHerringbone pattern
A
CollembolaRounded--Solid--
ArchaeognathaRoundedFar apart, rectangular cells-HollowYes-
ZygentomaRoundedIndistinct, irregular-Solid--
PsocopteraRounded--Solid--
ColeopteraRounded--Hollow--
TrichopteraRounded--HollowSome-
CulicidaeRoundedModerately dense-Solid--
BerothidaeRounded?????
KalligrammatidaeRounded?????
MicropterigidaeRoundedDenseYes?Solid-Dense
EriocranidaeRoundedDenseYesSolid--
CoelolepidaSerrated/roundedDenseYesHollowYes-
B
HerringboneRounded?-Solid-Dense–moderately dense
HollowSerrated/roundedDensePresentHollowSmall, between cross ridges-