Stephanopis pentacantha, Mello-Leitao, 1929

Machado, Miguel & Teixeira, Renato Augusto, 2021, Phylogenetic relationships in Stephanopinae: systematics of Stephanopis and Sidymella based on morphological characters (Araneae: Thomisidae), Organisms Diversity & Evolution (New York, N. Y.) 21 (2), pp. 281-313 : 292

“pentacantha clade ”

While two species of Stephanopis from Central America emerged close to the “ cambridgei clade”, the remaining Neotropical species were placed inside the “ Epicadus group” ( Fig. 6 ), a potential clade suggested by Silva-Moreira and Machado (2016) and partially recovered by Machado et al. (2017). A similar topology was recovered by Wheeler et al. (2017) with considerable support. Machado et al. (2017) recovered St. altifrons as closely related to the Neotropical species; however, the less inclusive approach on Australian representatives of the genus prevented these authors from considering genitalic features that have come to be crucial for elucidating the relationships in Stephanopis . In addition to the presence of a median spire on the thoracic portion of the prosoma (Char. 23, state 1; see Fig. 15f ) and the opisthosoma bearing five conical projections, this clade also diverges from Stephanopis by a series of sexual traits: male palp with a dorsally curved (Char. 101, state 2) and single-tipped RTA, absence of tegular ridge and tegulum smooth surface (Char. 108, state 0; Char. 110, state 0; see Fig. 17b ). Differing from St. altifrons and its correlated terminal taxa, this clade is composed of species where males lack the PrsP (Char. 115, state 0) and the CP (Char. 116, state 0). The female genitalia has a single pair of elliptical and smooth spermathecae, whereas females of Stephanopis have coiled spermathecae (Char. 89) with glandular heads (Char. 90) that are preceded by chamber-like copulatory ducts (Char. 86).

Along with Rejanellus , these are now the only known representatives in the “ Epicadus group” (sensu Silva-Moreira and Machado (2016)) with females having short CD and males lacking the RTAvbr on their palpi. Although sharing these features, the “ pentacantha clade” presents other characteristics (e.g. five conical projections on the opisthosoma; leafshaped setae; presence of MS) that set them apart from its sister genus. Its component species were grouped with strong branch support ( Fig. 3 ) and recovered by two synapomorphic characters: presence of ventral macrosetae on patellae I and II (Char. 54, state 1; see Fig. 13b ) and male palp bearing pearshaped tegulum (Char. 95, state 2; see Fig. 17b ). Despite the dichotomy with Rejanellus , the evidences listed above are interpreted as sufficient to justify the proposition of the “ pentacantha clade” as a new genus. Although well support- ed, the internal topology of the group is poorly resolved. This is due to the conservative morphology of its component species, which can only be distinguished from each other by details of their genitalia, such as the curvature, size and shape of the RTA and embolus, or the presence/absence of the median septum on the epigynal plate. A study focusing on their taxonomy is essential to explore these morphological aspects, as well as updating descriptions and diagnostic structures.

Figures

Fig. 6 Character transformations, detailed topology of the relationships between “ditissima clade” (blue) and Sidymella (stricto sensu); emergence of the “pentacantha clade” (purple) as part of the “Epicadus group”

Fig. 15 Characters relative to legs, claws and opisthosoma of specimens sampled in the present analysis: a Epicadus heterogaster, patella I. b Stephanopis pentacantha, patella I. c Isala cambridgei comb. nov., male tibial brushes. d Epicadus caudatus, trichobothrium and duster-shaped setae. e Tmarus elongatus, tarsal claws of the right leg I (mesial view). f Epicadus taczanowskii, tarsal claws of the right leg I (ectal view). g Epicadus heterogaster, tibia I. h Epicadus trituberculatus, opisthosoma

Fig. 17 Characters relative to opisthosoma and female genitalia of specimens sampled in the present analysis: a Stephanopis lata (arrows indicate abdominal setae clusters). b Stephanopis monulfi, barbed setae. c Stephanopis monulfi, ventral view of the epigynal plate. d Coenypha antennata comb. nov., ventral view of the epigynal plate. e Sidymella hirsuta, dorsal view of the epigynal plate (arrows indicate the direction of entry into the copulatory ducts). f Coenypha antennata comb. nov., dorsal view of the epigynal plate (arrows indicate the direction of entry into the copulatory ducts). g Sidymella sp.1, dorsal view of the epigynal plate. h Epicadus trituberculatus, dorsal view of the epigynal plate

Fig. 3 Clade supports obtained by relative Bremer index (above the branches) and symmetric resampling analysis (below the branches). A colour scheme is applied to represent the geographical distribution of the clades represented on the working phylogenetic hypothesis

Fig. 13 Characters relative to carapace and legs of specimens sampled in the present analysis: a Stephanopis pentacantha, proso- ma (detail of the procurve poste- rior eye row). b Paratobias championi sp. rev. (detail of the recurve posterior eye row). c Stephanopis fissifrons, prosoma (detail of the straight posterior eye row). d Stephanopis barbipes, prosoma (arrows indicate MOQ macrosetae). e Borporopactus cinerascens, prosoma (canoe- shaped tapetum). f Tmarus elongatus, tibiae I (trichobothria linearly distributed). g Stephanopis pentacantha, tibiae I (clustered trichobothria). h Coenypha edwardsi, leg I (arrows indicate mesial and ectal apophy- sis on femur)