The genus Stenoterommata Holmberg, 1881 (Araneae, Pycnothelidae) in the Cerrado and Atlantic Forest from Southeastern and Central Brazil: description of four new species

ABSTRACT Four new species of the mygalomorph spider genus Stenoterommata Holmberg, 1881 are described from Southeastern and Central Brazil. They are among the first described species that occur in the Brazilian Cerrado: S. neodiplornata Ghirotto & Indicatti, n. sp. from São Paulo state, in areas of Atlantic Forest, of savanna and of seasonal forest (Cerradão); S. chavarii Ghirotto & Indicatti, n. sp. from Botucatu, São Paulo state, in ecotonal areas of Atlantic Forest and Cerrado, as well as open anthropized areas similar to savannas; S. bodoquena Ghirotto & Indicatti, n. sp. from Bonito, Mato Grosso do Sul state, in areas of Atlantic Forest with Cerrado influences and seasonal forest; S. egric Ghirotto & Indicatti, n. sp. from Ibitipoca mountain range, Lima Duarte, Minas Gerais state, in Atlantic Forest and savanna areas. All new species are differentiated by the unique morphology of genitalia. Information on the natural history of S. neodiplornata Ghirotto & Indicatti, n. sp., S. bodoquena Ghirotto & Indicatti, n. sp. and S. egric Ghirotto & Indicatti, n. sp. is provided. Stenoterommata neodiplornata Ghirotto & Indicatti, n. sp. is the third species of the genus that can inhabit trunks and upper branches of the highest part of the trees. In addition, it is presented the first record of the genus for the Central Brazil, S. bodoquena Ghirotto & Indicatti, n. sp. from Mato Grosso do Sul.


INTRODUCTION
Pycnothelidae Chamberlin, 1917 was recently reestablished to the family level by Opatova et al. (2020) based on molecular analysis. Neotropical pycnothelids are represented by very small to medium sized spiders (Goloboff 1995;Indicatti et al. 2015). They are ground-dwelling, inhabiting the leaf litter, under fallen trunks and rocks, or in excavated burrows, open or closed with trapdoors or debris (Goloboff 1995).
Among the Neotropical pycnothelid genera is Stenoterommata, which was proposed by Holmberg (1881) to accommodate a new species, Stenoterommata platensis Holmberg, 1881, based on a male and female from the Pampas grasslands of Argentina. Currently, the genus comprises 20 described species, 14 of which occur in Brazil. The first species described from Brazil for the genus (although originally not described in it), were Stenoterommata maculata (Bertkau, 1880) and Stenoterommata leporina (Simon, 1891), both for the Atlantic Forest. All Stenoterommata species described to date occur either in humid (ombrophilous) Atlantic Forest of Argentina or Southern and Southeastern Brazil, or in the Pampas grasslands of Argentina, Brazil and Uruguay, except for Stenoterommata quena Goloboff, 1995, occurring in the seasonally dry Chaco of northwestern Argentina. Many species are sympatric, and most of the Brazilian species were described very recently, indicating the high potential for new species yet to be found (Indicatti et al. 2008(Indicatti et al. , 2017. Although the Atlantic Forest in the southeastern Brazil borders the Cerrado domain, and even when S. quena occurs in the Argentinean Chaco which is similar to the Cerrado, to date there are no Stenoterommata species occurring in Cerrado areas, nor in ecotonal zones with the more hygrophilous Atlantic Forest (Goloboff 1995;Indicatti et al. 2008;Ferretti & Pompozzi 2016;Indicatti et al. 2017;Bertani et al. 2017). Also, no species of the genus are recorded for the more inland, dryer types of Atlantic Forest, such as deciduous or semideciduous forests. ZOOSYSTEMA • 2021 • 43 (17) The Brazilian Cerrado covers almost one quarter of country territory (Sano et al. 2009), and is historically and very frequently treated as a single biome. However, recently it has been noted that the Cerrado is, instead, a complex phytogeographical domain that comprises three major different biomes, savanna formations, open grasslands and seasonal forests (Cerradão) (Batalha 2011). In the state of São Paulo, there are few remains of the already scarce original Cerrado coverage, mostly represented by seasonal forests or ecotonal zones with Atlantic Forest fragments scattered through the state (Ratter et al. 1997). Such an environment is protected at the Floresta Nacional de Ipanema, which harbors seasonal and semideciduous forests and small patches of savannas (Albuquerque & Rodrigues 2000;IBAMA 2006). The Estação Ecológica de Itirapina (ESEC Itirapina) comprises one of the largest protected Cerrado areas in the state. Most of the ESEC Itirapina area is covered by open grasslands and savanna formations, but small fragments of seasonal forests are present (Brasileiro et al. 2005;IF 2006). In the state of Minas Gerais, the Ibitipoca mountain range bears an interesting mosaic area comprising ombrophilous and semideciduous Atlantic Forest patches that infiltrate towards a rocky terrain covered in savanna (Borges et al. 2010;Moreira et al. 2018). In the state of Mato Grosso do Sul, there are more areas of Cerrado coverage, mainly dense savanna and seasonal forests. Moreover, there are also some Atlantic Forest relictual patches as the Parque Nacional da Serra da Bodoquena, which is a semideciduous forest surrounded by seasonal forests and savannas, thus heavily influenced by the Cerrado (Damasceno-Júnior et al. 2000;Seixas 2005;ICMBio 2013).
In this study, four new species of Stenoterommata are described, found in Cerrado, Alantic Forest (semideciduous forests), or ecotonal zones. In addition, new information on the natural history for the genus is provided, as well as the first record of Stenoterommata for the Central Brazil.
note. -Examination of two exuviae from consecutive molts of a juvenile female from ESEC Itirapina showed little variation in the spermathecae, even in size (Fig. 6A, B). The cephalothorax size of the exuvia of the first molt is 3.21 long; second molt, 4.46 long; the current size in life is 5.54 long. Many more small to medium sized juvenile spiders were revealed by carefully disassembling the soil from the ravines. At FLONA Ipanema, specimens were found in savanna formations within rock outcrops, bordered by Atlantic Forest and seasonal forest areas (Fig. 7C, D). Few specimens were found in ravines, in an anthropized area. Most burrows were found in tree trunks  and between the rock crevices (Fig. 8E, F). In the trees, the burrows occurred at different heights, from the ground near roots up to six meters. Most specimens were found in Cambará trees, Gochnatia polymorpha (Less.) Cabrera ( Fig. 9D-F), a typical Cerrado species with very rugose thick bark (ridges with 20-50 mm). This allow the spiders to survive fires, which naturally occurs in savannas or forests, even when burning the tree bark (R. P. Indicatti, personal observ.) (Fig. 9D). Although not common for the genus, the behavior of inhabiting live trees also can be observed in S. arnolisei and S. palmar (Indicatti et al. 2008;2017), as well as an undescribed species from Parque Nacional do Itatiaia, Rio de Janeiro state, indicating that activity flow between soil and upper branches of the highest part of the trees may take place. This behavior has not yet been observed in any other Pycnothelidae genus, in which other known representatives always inhabits burrows associated with the soil (Goloboff 1995;Lucas et al. 2008;Indicatti 2013;Pérez-Miles et al. 2014; Ferretti 2015; R. P. Indicatti, pers. obs.). Within live tree barks the spiders behaves the same as those that live in the ground or ravines, as observed when the tree barks are removed (Fig. 9C), exposing remains of prey exoskeleton and old exuviae in end of chamber (Fig. 9C). The same occurs with some males, which could be observed resting near juvenile and female burrows (Fig. 9D, E). Individuals kept alive in the laboratory constructed burrows in the soil, lined with fine silk, with 1-2 openings. The openings were sometimes observed to be closed with silk and soil for some days to few weeks, when the spider reopened the burrow. They were able to take down large prey (roaches, moths, crickets), c. 1.5 × their total body size.  description

nAturAl history
Only two males and two juveniles were found by active search. The juveniles were found inside fallen rotting logs (Fig. 12 D,E), which were already soft and loose, where they supposedly constructed burrows (as they were visible after splitting the log, no such burrows could be seen). Both adult males were found underneath fallen logs. In the areas they were found, no burrows were visible in the soil.

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A D E    14D); from S. palmar by the palpal tibia with 2 spines on prolateral-medial region (Fig. 14E) and presence of ITC on legs III, IV. Females can be distinguished from the remaining species of the genus, except from S. quena Goloboff, 1995, by the presence of metatarsal preening combs on leg I and on VP and VR sides of leg II; differs from S. quena and resembles S. platensis Holmberg, 1881 and S. iguazu by the spermathecae with two independent bases on each side (Fig. 16) and prolateral spines 1-1-1 on patella III; differs from them by the elongated basal dome, metatarsal preening combs on all legs and anterior eye row slightly recurved (Fig. 15A).
etymology. -The specific name is a patronym in honor of João Lucas Chavari, friend of the last authors and collector of several mygalomorph spiders from Brazil. description
etymology. -The specific epithet is an acronym taken from "Espeleo Grupo Rio Claro -EGRIC" which organized the expedition to Ibitipoca mountain range that led the first author to collect the type specimens, and in recognition of their efforts in the study and preservation of Brazilian caves.