Saurona Huertas & Willmott, 2023

Espeland, Marianne, Nakahara, Shinichi, Zacca, Thamara, Barbosa, Eduardo P., Huertas, Blanca, Marín, Mario A., Lamas, Gerardo, Benmesbah, Mohamed, Brévignon, Christian, Casagrande, Mirna M., Fåhraeus, Christer, Grishin, Nick, Kawahara, Akito Y., Mielke, Olaf H. H., Miller, Jacqueline Y., Nakamura, Ichiro, Navas, Vanessa, Patrusky, Brooke, Pyrcz, Tomasz W., Richards, Lindsay, Tan, Denise, Tyler, Stephanie, Viloria, Angel, Warren, Andrew D., Xiao, Lei, Freitas, André V. L. & Willmott, Keith R., 2023, Combining target enrichment and Sanger sequencing data to clarify the systematics of the diverse Neotropical butterfly subtribe Euptychiina (Nymphalidae, Satyrinae), Zoological Research 2023, pp. 1-73 : 22-58

Saurona Huertas & Willmott , genus novum.

Type species — Euptychia aurigera var. triangula Aurivillius, 1929 , by present designation.

Zoobank registration: https://zoobank.org/Nomenclatural Acts/25189D52-EE44-4A98-A286-08403155CA6D

Systematic placement and diagnosis. Saurona gen.n. is a member of the ‘ Hermeuptychia clade’, in which its type species, Euptychia triangula Aurivillius, 1929 , is strongly supported as sister to Hermeuptychia (SH-aLRT = 98.8, UFB = 99). Our results ( Figures 5 , S 2 and S 3 ), morphology ( Huertas, 2014) and DNA barcodes (C. Fahraeus, unpublished data) support a sister relationship between Saurona triangula comb.n. and the only other described species included here within this new genus, Saurona aurigera comb.n. These two species can be distinguished from all other Euptychiina as follows: (a) a patch of elongate, dark androconial hair-like scales is present along the distal edge of the DHW discal cell ( Figure 14a ); (b) the HW costa is expanded anteriorly, with concomitant shortening of the HW discal cell and basal migration of the ends of veins Rs and Sc + R1 ( Figure 14a ); (c) the VFW anal margin where it overlaps with the DHW androconial scales has an elongate patch of pale, sparse, needle-like scales along the basal part of vein 2A, surrounded by shiny white scales; (d) the DFW has an elongate androconial patch of shiny silver greyish scales along the basal half of vein M 2 ( Figure 14a ). The ventral portion of the anal tube in the male genitalia is weakly sclerotized and covered with minute studs ( Figure 15d ), a distinctive character shared with the sister genus Hermeuptychia (e.g. Zacca et al., 2021), whereas the slender, upwardly curving brachia differ from the thicker, posterior/ventrally pointing brachia of Hermeuptychia (e.g. Cong & Grishin, 2014; Nakahara, Tan, et al., 2016; Zacca et al., 2021). Both described Saurona gen.n. species also share a distinctive, dense covering of hair-like setae over the uncus. Finally, the configuration of the VHW postdiscal ocelli is almost unique within the subtribe, with the row of circular black ocelli with large central silvery pupils surrounded by orange scaling ( Figure 14c,e ), superficially similar only to Euptychia ordinata Weymer, 1911 and Euptychia insignis Butler, 1867 (which are placed here in the ‘ Amphidecta clade’). The simple VHW ocelli readily distinguish the two described species from several otherwise somewhat similar species in Argentaria gen.n. The female genitalia of S. triangula comb.n. ( Figure 15g – j ) have several distinctive characters (described further below), but none that can be considered synapomorphies since they are not shared with a known undescribed species that should be placed in this genus (Huertas et al., in preparation).

Etymology. The generic name is based on that of the main antagonist, Sauron, in J. R. R. Tolkien ’ s novel ‘The Lord of the Rings’. The name alludes to the distinctive fused orange rings that encircle the VHW ocelli, and to avoid unhelpful changes to associated specific names as mandated by the ICZN (Article 31.2, ICZN, 1999), we treat it as a feminine noun in the nominative singular.

Description ( Figures 14 and 15 ). Some notable characters include: eyes naked; pterothoracic legs dorsally darker except tips of tarsomeres ringed with pale scales, tibia with two principal longitudinal rows of spines ventrally, pair of spurs of similar length at distal end of tibia, first tarsomere with three principal longitudinal rows of spines ventrally, remaining tarsomeres with four principal longitudinal rows of spines ventrally. Small Euptychiina (FW length typically 17 – 19 mm). FW and HW compact, HW skewed with costal margin extended anteriorly and distal tips of veins Rs and Sc + R1 shifted basally, and FW anal margin expanded posteriorly (in male). Male DFW with elongate androconial patch of shiny grey scales along the basal half of vein M 2; DHW with patch of elongate androconial hair-like scales at distal edge of discal cell, and associated androconial scales at overlapping anal margin of VFW, as described above. No strong sexual dimorphism in wing pattern: VFW lacking ocelli, VHW with five distinct postdiscal ocelli (and one indistinct, in cell M 1 -Rs), all of similar form, circular, black, with large, single central silvery pupil in each, surrounded by orange scaling. Female with slightly more rounded wings than male but otherwise similar in pattern, except as noted above and in lacking the DHW, VFW and DFW androconial scales. Male eighth abdominal tergite reduced dorsally, leaving a sclerotized strip along anterior edge and broader band along ventral edge ( Figure 15a ); dense covering of hair-like setae on uncus in two described species, aedeagus straight and lacking cornuti, ventral portion of anal tube weakly sclerotized and covered with minute studs, brachia pointing sharply dorsally of uncus. Female genitalia with eighth tergite complete, intersegmental membrane between seventh and eighth abdominal segments somewhat wrinkled and expandable without a sclerotized plate ventrally, eighth segment with large, posteriorly pointed irregular lateral sclerotized plate fused ventrally with a broad, scoop-like ventrally sclerotized antrum, band of black scales posterior to eighth segment encircling abdomen, base of papilla analis unusually strongly sclerotized, ductus bursae narrow, corpus bursae elongate and with two narrow, elongate signa.

Distribution and natural history ( Figure 16 ). Saurona gen.n. is confined to lowland rainforest in the south-western Amazon, where both described species can be found in the same localities. The immature stages and hostplants have not been described.

Discussion. Weymer (1911, p. 194, pl. 46 e) described Euptychia aurigera in his ‘Hesione group’ (now Pareuptychia ), but also stated that it ‘resembles no other Euptychia ’. His description and figure of the ventral surface are consistent with one another, and the latter shows an attenuated VFW white band and dark brown line separating the white VHW postdiscal band from the orange surrounding the ocelli. These ventral characters are evident in the putative syntype specimen examined at the SMTD, and distinguish the species from the only other described congener. Aurivillius (1929) described Euptychia aurigera var. triangula based on three males from Rio Purus, Hyutanahan (= Hiutanaa ˜) (Brazil, Amazonas), and accurately described several characters that distinguish the species from S. aurigera comb.n. and which are evident in the syntype specimens examined at the RMS and figured by Warren et al. (2022). We selected Euptychia triangula as the type species for this genus since it was the species for which we had most complete DNA sequence data. Neither species was mentioned by Forster (1964) in his generic reorganization of Euptychiina , and Lamas (2004) placed both species in Splendeuptychia , among several superficially similar other species, until their true relationships could be determined. Based on a morphological phylogenetic study, Huertas (2014) found both species to be distantly related to other species then placed in Splendeuptychia . The morphological phylogenetic study of Marín et al. (2017) placed Splendeuptychia triangula as sister to Splendeuptychia ackeryi and Splendeuptychia doxes (both of which are placed here in Nhambikuara ), but without strong support, and this placement may have resulted from superficial similarity in ventral wing pattern elements. Otherwise, we do not know of any morphological characters that strongly support an alternative hypothesis of relationships from that proposed in this paper on the basis of molecular data, or the reasonable placement of the two species included here within Saurona gen.n. in any described genus. In our analysis the branch separating Saurona gen.n. from Hermeuptychia is much longer than any within either genus, and the two genera otherwise share no obvious diagnostic morphological or ecological characters.

Saurona Huertas & Willmott , gen.n.

aurigera (Weymer, [1911]) , comb.n., was Splendeuptychia

triangula ( Aurivillius, 1929) , comb.n., was Splendeuptychia

Figures

FIGURE 2 Phylogeny of Euptychia based on the FULL dataset. Interpretation of support values can be found in the legend. The scale bars under the butterfly images equal 1 cm.

FIGURE 3 Phylogeny of the Cyllopsis clade based on the FULL dataset. Interpretation of support values can be found in the legend. The scale bars under the butterfly images equal 1 cm.

FIGURE 5 Phylogeny of the Hermeuptychia clade and nearby genera based on the FULL dataset. Interpretation of support values can be found in the legend. The scale bars under the butterfly images equal 1 cm.

FIGURE 14 Saurona triangula comb.n. (a) male wing venation—stippled area on FW shows dorsal androconial scales around vein M2 and ventral androconial scales around vein 2A, androconial hair-like scales at anterior edge discal cell are also indicated; (b and c) male dorsal (b) and ventral (c); (d and e) female dorsal (d) and ventral (e). Scale bars 1 cm.

FIGURE 15 Saurona triangulacomb.n. A-F, male genitalia (dissection KW-21-31), lateral tip abdomen (a), lateral (b) with posterior view juxta, dorsal (c), ventral (d), aedeagus lateral (e) and dorsal (f); (g–j), female genitalia (dissection USNM loan 2090579), lateral view exterior tip abdomen (g), ventral view exterior tip abdomen (h), dorsal view interior abdomen (i), corpus bursae perpendicular to signa (j).Scale bars 1 mm.

FIGURE 16 Saurona gen.n. Species diversity mapped on a 2 degree grid. Colours ranging from dark green to red represent increasing diversity.