Paecilaema, C. L. Koch, 1839

Kury, Adriano B. & Medrano, Miguel, 2018, A whiter shade of pale: anchoring the name Paecilaema C. L. Koch, 1839 onto a neotype (Opiliones, Cosmetidae), Zootaxa 4521 (2), pp. 191-219 : 215

Key to the genera revalidated from the synonymy of Paecilaema

1. DS outline alpha-type; legs III-IV much stronger than I-II; Fe IV incrassate, armed with prolateral rows of strong spines.... 7

1’ DS outline beta-type or delta-type; legs III-IV comparable to I-II; Fe IV not incrassate, unarmed....................... 2

2. Varied white markings on scutum, but never forming a true lyra; scutal armature on area III weak; Fe IV thick, long; tarsal count of posterior legs high ( II 15– 19, III 10– 12 , IV 11 -–15)................................................... 3

2’ True lyra present; Fe IV very slender; scutal area III with pair of spines (except for P. muticum ); tarsal count of posterior legs low to medium ( II 9–14, III 6–8 , IV 6–9)................................................................... 6

3. Scutal shape delta; scutal marking as a Discosomaticus -like ring; areas I and III with white rounded tubercles................................................................................................. Soaresella ( Panama)

3’. Scutal shape beta, with variations; scutal markings without ring; area I unarmed, area III with small tubercles or granules... 4

4. Fe I to IV getting gradually thicker distally and covered with coarse granulation; Fe IV slightly curved, moderately long ( 8 mm).......................................................................... Pararhauculus ( Costa Rica)

4’ Fe I-IV straight and uniform (not filiform), entirely smooth, elongate (longer than 14 mm)............................ 5

5. DS outline beta-classic; Ch hand dimorphic, strongly swollen in males; Fe IV very long ( 15 mm). Poecilaemula ( Costa Rica)

5’. DS outline beta-diamond (with constrictions smoothed); Ch hand monomorphic; Fe IV extremely long ( 18 mm)............................................................................................ Paecilaemella ( Ecuador)

6. Lyra rudimentary, only with inner outline; without diaphanous body and with large U-shaped fenestra magna; solid punctulations fused forming outline of FM and partly over the carapace groove, otherwise isolated along the laterals of dorsal scutum ( Figs 5 A–C); low tarsal counts (6/ 13/6-7/6-7); Fe IV short (4.5 mm)............ Metavononoides (E Brazil, interior forest)

6’ True lyra present, with set of 6 fenestrae and containing diaphanous body, sometimes with different shades of pale; solid punctulations present but not restricted to lyra outline ( Figs 4 , 5 D–F, Figs 6 A–F); high tarsal counts (6–7/12– 18/7–9/7–10); Fe IV long ( 10 mm)......................................................... Paecilaema (E Brazil, coastal forest)

7. Scutal area III entirely unarmed; Fe IV of male with prolateral proximal row of spines, short (4.8 mm).................................................................................................. Meterginoides ( Costa Rica)

7’. Scutal area III with pair of low acuminate tubercles; Fe IV of male with retro- and prolateral rows of strong spines, moderately long (7.3 mm)...................................................................... Meterginulus ( Mexico)

Figures

FIGURE 4. Lyra of Paecilaema u-flavum (schematic, to show the regions recognized here). Abbreviations: FM = fenestra magna; FT = fenestra triangularis. FLA and FLP = fenestrae laterales anterior and posterior.

FIGURE 5. Metavononoides and Paecilaema spp., body, dorsal view, schematic: A. M. barbacenensis. B. M. guttulosus. C. M. orientalis. D. P. ornatissimum. E. P. albosigillatum. F. P. albisectum. Color scheme of lyre as in Fig. 4: Olive-green = solid punctulations; shades of orange = diaphanous body of lyre.

FIGURE 6. Paecilaema spp., body, dorsal view, schematic: A. P. peculiare. B. P. preciosum. C. P. muticum. D. P. melanacanthum. E. P. renneri. F. P. lyra. Color scheme of lyre as in Fig. 4: Olive-green = solid punctulations; shades of orange = diaphanous body of lyre.