taxonID	type	description	language	source
D8F28DADC0065064BA8575B8757682EF.taxon	description	Figures 4, 5, 6, 7, 18, Tables 1, 2	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
D8F28DADC0065064BA8575B8757682EF.taxon	diagnosis	Diagnosis. Euathlus basalticus sp. nov. can be distinguished from all known congeners by a unique combination of characters in males: a dark tibial apophysis with two robust branches, the PB shorter than the RB and bearing a strong internal basal spine, while the RB has a prominent internal subapical spine (Fig. 4 C – E), palpal organ piriform (Fig. 5) embolus arises gradually from the tegulum, without a distinct junction, presence of 1 – 2 small teeth at the tip of the prolateral inferior keel. Females can be distinguished from congeners (except from E. condorito) by having two wide seminal receptacles, rounded at the upper margin. Each receptacle bears a large semi-spheroid lateral chamber connected by a constricted duct and projecting from the lower outer margin. In addition, females differ from those of E. condorito in the orientation of the lateral chamber, which has its longest axis parallel to the lateral margin of the seminal receptacle (Fig. 6 D – F).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
D8F28DADC0065064BA8575B8757682EF.taxon	description	Description male. Male holotype (UNS M 1122). — Coloration (in alcohol): Carapace brown, abdomen dark brown, lighter lines on dorsal femur, patellae and tibiae of palps and legs I – IV, maxillae and labium yellow, dark yellow sternum (Fig. 4 A, B). — Coloration (in life): Legs I – IV and palps with light longitudinal lines on the dorsal surface of femora, patellae, and tibiae. Legs covered with long yellowish hairs (Fig. 7 D). Whitish setae present on the margins of the cephalothorax and the proximal area of the chelicerae. Abdomen with reddish hairs anteriorly and yellowish hairs posteriorly. Spinnerets covered with orange hairs. Total length 18.07. — Prosoma: Carapace length 9.08, width 8.95. Anterior eye row procurved, posterior one recurved. Eye sizes and interdistances: AME 0.15, ALE 0.39, PME 0.24, PLE 0.25, AME - AME 0.30, AME - ALE 0.11, PME - PME 0.52, PME - PLE 0.07, ALE - PLE 0.22, OQ length 0.88, width 1.26. Clypeus 0.12. Fovea transverse, short, deep, slightly procurved, width 0.89. Labium length 1.12, width 1.56, with 65 cuspules. Maxillae (right / left) with 118 / 120 cuspules. Sternum length 4.44, width 3.58 (Fig. 4 B). Chelicerae with 7 large teeth on promargin of furrow and 10 small teeth on the proximal area of retromargin. — Appendages: Tarsi I – IV densely scopulate with scopula entire, undivided. Metatarsi I 2 / 3 scopulated, II 1 / 2 scopulated, III 1 / 3 scopulated, IV 1 / 4 apically scopulated. Leg and palpal segments lengths in Table 1. Spination: Patellae of legs II – IV, femur of legs I and IV, tarsi of palps and legs I – IV, 0. Femora: palp 0 - 0 - 0 - 1 P; II 0 - 0 - 1 - 2 P; III 0 - 0 - 0 - 1 P, 0 - 1 - 1 - 1 R. Patellae: palp 0 - 0 - 1 - 0 P; I 0 - 0 - 0 - 1 V. Tibiae: palp 2 - 2 - 0 - 0 V, 0 - 1 - 0 - 0 P; I 2 - 0 - 2 - 0 V, 0 - 1 - 0 - 1 P, 1 - 0 - 0 - 0 R; II 2 - 2 - 0 - 4 (ap) V, 0 - 1 - 0 - 1 P, 1 - 1 - 0 - 0 R; III 1 - 1 - 0 - 4 (ap) V, 1 - 2 - 1 - 0 P, 1 - 2 - 1 - 0 R; IV 2 - 3 - 1 - 4 (ap) V, 0 - 1 - 0 - 1 P, 0 - 2 - 1 - 0 R. Metatarsi: I 1 - 0 - 0 - 1 V; II 1 - 1 - 0 - 1 (ap) V; III 2 - 1 - 1 - 3 (ap) V, 1 - 0 - 1 - 1 P, 1 - 1 - 0 - 1 R; IV 2 - 0 - 2 - 3 (ap) V, 1 - 0 - 1 - 1 P, 0 - 2 - 1 - 1 R. Metatarsus I straight. Tibial apophysis of leg I dark with two short branches, RB slightly longer than prolateral, both well-developed and originating from a common base, PB with a basal internal short strong spine, RB with a subapical internal short strong spine (Fig. 4 C – E). Metatarsus I rests retrolaterally on the tibial apophysis when flexed. — Opisthosoma: Abdominal urticating setae patch large, reniform and central, with only type III urticating setae. Four spinnerets, PMS 0.7 long and PLS three segmented, basal segment 0.9 long, medial segment 0.8 long, and apical segment 1.2 long. — Genital organs: Palpal organ piriform, with a relatively broad embolus that tapers distally. The embolus is long and curved retrolaterally. Prolateral keels are unequally developed, with PI more developed than PS. The PI bears one or two well-developed teeth, located distally on the embolus but not entirely at the apex. An apical keel is also present (Fig. 5).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
D8F28DADC0065064BA8575B8757682EF.taxon	description	Description female. Female paratype (UNS M 1492). — Coloration (in alcohol): carapace brown, margins of carapace yellow, yellowish lines on dorsal femur, patellae and tibiae of palps and legs I – IV, abdomen dark brown (Fig. 6 A). — Coloration (in life): hole body reddish. Legs I – IV and palps exhibit distinct light longitudinal lines on the dorsal surfaces of the femora, patellae, and tibiae. Legs and abdomen are densely covered with long yellowish hairs. Margins of carapace, the base of the legs, and the proximal area of the chelicerae are light brown. Patch of urticating setae yellow (Fig. 7 C). Total length 15.60. — Prosoma: Carapace length 6.52, width 6.18. Anterior eye row procurved, posterior one recurved. Eye sizes and interdistances: AME 0.12, ALE 0.34, PME 0.19, PLE 0.25, AME - AME 0.28, AME - ALE 0.11, PME - PME 0.47, PME - PLE 0.07, ALE - PLE 0.12, OQ length 0.96, width 1.14. Clypeus 0.12. Fovea transverse, short, deep, slightly procurved, width 0.41. Labium length 0.91, width 1.31 with 52 cuspules. Maxillae (right / left) with 107 / 103 cuspules. Sternum length 3.37, width 3.24 (Fig. 6 B). Chelicerae with 9 well-developed teeth on promargin of furrow and 3 small teeth on the proximal area of retromargin. — Appendages: Tarsi I – IV densely scopulate, undivided. Metatarsi I 3 / 4 scopulated, II 1 / 2 scopulated, III 1 / 3 scopulated, IV 1 / 4 apically scopulated. Legs and palpal segments length in Table 2. Spination: Femora of legs I – IV, patellae and tarsi of palp and legs I – IV, 0. Femora: palp 0 - 0 - 0 - 1 P. Tibiae: palp 1 - 1 - 1 - 3 (ap) V; I 0 - 1 - 0 - 0 V, 0 - 0 - 0 - 1 (ap) P; II 0 - 0 - 0 - 3 (ap) V; III 0 - 2 - 0 - 3 (ap) V, 0 - 1 - 1 - 0 P, 0 - 0 - 1 - 0 R; IV 0 - 1 - 0 - 2 (ap) V, 0 - 1 - 1 - 1 P, 0 - 2 - 0 - 1 R. Metatarsi: I 0 - 1 - 0 - 1 (ap) V; II 0 - 1 - 0 - 1 (ap) V; III 2 - 2 - 0 - 3 (ap) V, 1 - 1 - 0 - 1 P, 0 - 1 - 0 - 0 R; IV 1 - 2 - 1 - 4 (ap) V, 0 - 1 - 0 - 1 P, 1 - 2 - 1 - 1 R. — Opisthosoma: Abdominal urticating setae patch large, reniform and central, with types III and IV present. Four spinnerets, PMS 0.74 long and PLS three segmented, basal segment 1.07 long, medial segment 0.62 long, and apical segment 0.82 long. — Genital organs: Spermatheca with two wide seminal receptacles with rounded shape facing upwards, each with a semi spheroid chamber pointing laterally, connected with a constricted duct, projecting from the lower outer margin of each receptacle (Fig. 6 D).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
D8F28DADC0065064BA8575B8757682EF.taxon	etymology	Etymology. The specific name “ basalticus ” is a Latin adjective in the nominative singular. It refers to the strong association of this species with basaltic substrates, as specimens were exclusively found in areas dominated by basaltic rock formations. The name is derived from the Latin “ basaltes ” with the suffix “ - icus, ” meaning “ belonging or pertaining to. ”	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
D8F28DADC0065064BA8575B8757682EF.taxon	distribution	Distribution and natural history. These spiders are found in rocky formations (Fig. 7). These spiders inhabit rocky outcrops composed of andesitic and basaltic-andesitic lavas typical of the Caviahue – Copahue volcanic complex. They occur at elevations exceeding 1 600 m a. s. l., reaching near the summit of Copahue volcano at nearly 3 000 m a. s. l. (Varekamp et al. 2016). The lower montane zone shows the highest plant diversity due to abundant precipitation and moderate thermal conditions, with climax vegetation corresponding to Nothofagus forests and thickets mixed with the conifer Araucaria araucana (Mol.) Koch., which has its northernmost distributional limit in Argentina within this park. Key bioindicator species of the shrub-grass steppe ecotone include Festuca scabriuscula Philippi, Berberis empetrifolia Lamarck, and Ephedra frustillata Miers, creating the complex Andean-Patagonian ecosystem (Gandullo et al. 2004). Andesite and basaltic andesite are the predominant rock types of this basin (Cabrera et al. 2020) (Fig. 18).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	description	Figures 8, 9, 10, 11, 18, Tables 3, 4	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	diagnosis	Diagnosis. Euathlus kupal sp. nov. can be distinguished from all known congeners by a unique combination of characters in males: tibial apophysis with two robust branches, the PB shorter than the RB and both bearing strong internal spines (Fig. 9), palpal organ slender with a long embolus with multiple small teeth along the curvature of the embolus: six well-defined teeth of varying sizes and three to four smaller teeth (Fig. 10). Females are diagnosed from all known species by the shape of the spermathecae, consisting of two low seminal receptacles with small mounds along the upper margin, each bearing a large semi-spheroid lateral chamber oriented downward, connected by a wide duct (Fig. 11 D, E).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	description	Description male. Male holotype (MACN - Ar 46352). — Coloration (in alcohol): Carapace reddish with long whitish setae on margins, legs light brown / orange, abdomen brown with long yellowish setae, booklung openings yellowish (Fig. 8 A – E). Total length 23.22. — Prosoma: Carapace length 12.32, width 11.47. Anterior eye row procurved, posterior one recurved. Eye sizes and interdistances: AME 0.20, ALE 0.48, PME 0.28, PLE 0.43, AME - AME 0.40, AME - ALE 0.19, PME - PME 0.74, PME - PLE 0.11, ALE - PLE 0.19, OQ length 1.33, width 1.68. Clypeus 0.16. Fovea transverse, deep, slightly recurved, width 1.30. Labium length 1.65, width 1.80, with 116 cuspules. Maxillae (right / left) with 110 / 120 cuspules. Sternum length 5.14, width 4.35 (Fig. 8 B). Chelicerae with 7 well-developed teeth on promargin of furrow and 4 small teeth on the proximal area of retromargin. — Appendages: Tarsi I – IV densely scopulated, undivided. Metatarsi I fully scopulated, II 2 / 3 scopulated, III 1 / 2 scopulated, IV 1 / 4 apically scopulated. Leg and palpal segments lengths in Table 3. Spination: Patellae of palp and legs III and IV, tarsi of palp and legs I – IV, 0. Femora: palp 0 - 0 - 0 - 1 P; I 0 - 0 - 0 - 1 P; II 0 - 1 - 0 - 1 P, 0 - 1 - 0 - 0 R; III 1 - 1 - 0 - 1 P, 1 - 0 - 0 - 0 D; IV 0 - 1 - 0 - 0 P. Patellae: I 0 - 0 - 0 - 1 V. Tibiae: palp 1 - 1 - 0 - 1 P, 1 - 0 - 0 - 0 R; I 2 - 2 - 0 - 2 (ap) V, 2 - 1 - 0 - 0 P, 2 - 1 - 0 - 0 R; II 3 - 3 - 0 - 3 (ap) V, 1 - 1 - 1 - 0 P; III 2 - 1 - 0 - 3 (ap) V, 2 - 2 - 1 - 0 P, 1 - 2 - 1 - 0 R; IV 2 - 1 - 0 - 3 (ap) V, 1 - 2 - 1 - 0 P, 0 - 2 - 1 - 0 R. Metatarsi: I 1 - 0 - 0 - 1 (ap) V; II 1 - 0 - 0 - 1 (ap) V; III 3 - 2 - 0 - 2 (ap) V, 1 - 1 - 0 - 1 P, 1 - 1 - 1 - 1 R; IV 3 - 2 - 1 - 3 (ap) V, 1 - 1 - 0 - 1 P, 2 - 2 - 1 - 1 R. Metatarsus I straight. Tibial apophysis of legs I consists in two short well-developed black branches originating from a common base. Retrolateral branch slightly longer than prolateral, PB with a basal internal short strong spine, RB with a subapical internal short strong spine (Fig. 9). Metatarsus I rests retrolaterally on the tibial apophysis when flexed. — Opisthosoma: Abdomen dorsally with a rectangular patch of urticating setae with types III and IV. Four spinnerets, PMS 1.15 long and PLS three segmented, basal segment 1.56 long, medial segment 0.86 long, and apical segment 1.01 long. — Genital organs: Palpal organ piriform, elongated, with a relatively slender tegulum. Embolus long and slightly slender, starting to curve proximally to the tegulum in a retrolateral direction. Prolateral keels unequal, PS flat and weakly developed, PI well developed, bearing six well-defined teeth of varying sizes and three to four smaller teeth along the curvature of the embolus (Fig. 10).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	description	Description female. Female paratype (MACN - Ar 46354). — Coloration (in alcohol): Carapace and legs light brown / orange, abdomen brown (Fig. 11 A). Total length 18.92. — Prosoma: Carapace length 8.87, width 7.91. Anterior eye row procurved, posterior one recurved. Eye sizes and interdistances: AME 0.14, ALE 0.44, PME 0.23, PLE 0.36, AME - AME 0.32, AME - ALE 0.18, PME - PME 0.59, PME - PLE 0.08, ALE - PLE 0.15, OQ length 0.83, width 1.46. Clypeus 0.20. Fovea transverse, short, slightly recurved, width 0.86. Labium length 1.21, width 1.43, with 53 cuspules. Maxillae (right / left) with 82 / 76 cuspules. Sternum length 4.16, width 3.66 (Fig. 11 B). Chelicerae with 7 large teeth on promargin of furrow and 4 small teeth on the proximal area of retromargin. — Appendages: Tarsi I-IV densely scopulated, undivided. Metatarsi I 2 / 3 scopulated, II 1 / 2 scopulated, III 1 / 3 scopulated, IV 1 / 4 apically scopulated. Leg and palpal segments lengths in Table 4. Spination: Femur of leg IV, patellae and tarsi of palp and legs I – IV, 0. Femora: palp 0 - 0 - 0 - 1 P; I 0 - 0 - 0 - 1 (ap) P, II 0 - 0 - 0 - 1 (ap) P, 0 - 0 - 0 - 1 R. Tibiae: palp 1 - 2 - 0 - 3 (ap) V, 0 - 0 - 0 - 1 R; I 0 - 1 - 0 - 0 V, 0 - 0 - 0 - 1 (ap) P; II 0 - 1 - 0 - 1 (ap) V, 0 - 0 - 0 - 1 (ap) P; III 0 - 2 - 0 - 2 (ap) V, 0 - 1 - 1 - 0 P, 1 - 0 - 1 - 0 R, IV 0 - 2 - 1 - 3 (ap) V, 0 - 0 - 1 - 0 P, 1 - 0 - 1 - 0 R. Metatarsi: I 0 - 1 - 0 - 1 (ap) V; II 0 - 1 - 0 - 1 (ap) V; III 2 - 2 - 0 - 3 (ap) V, 1 - 1 - 0 - 1 P, 1 - 1 - 0 - 1 R; IV 2 - 2 - 1 - 3 (ap) V, 0 - 1 - 0 - 1 P, 1 - 2 - 1 - 1 R. — Opisthosoma: Abdomen with large oval urticating setae patch with types III and IV. Four spinnerets, PMS 0.68 long and PLS three segmented, basal segment 1.63 long, medial segment 0.95 long, and apical segment 1.11 long. — Genital organs: Spermatheca with two low seminal receptacles with mounds on its upper margin, each with a large semi-spheroid lateral chamber oriented downward, connected with a wide duct without noticeable constriction (Fig. 11 D, E).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	etymology	Etymology. The specific name “ kupal ” is a noun in the nominative singular, used in apposition to the generic name. It is derived from the Mapuche language, where it means ‘ family’ or ‘ lineage. ’ This term honors the author’s family and also serves as a recognition of the Mapuche people who historically inhabited the region where this species was discovered.	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
619A386ACC845524B480847CC3038C64.taxon	distribution	Distribution and natural history. The region where this species inhabit is characterized by arid and cold conditions, with large daily and annual temperature ranges and scarce precipitation with a mean annual precipitation of about 360 mm. The average annual temperature is 12 ° C. Winters are cold, with average temperatures around 5 ° C, while summers are mild, averaging 20 ° C (Tello et al. 2021). This area comprises an overlap of three floristic districts: Monte Occidental, Patagonian Steppe, and the High Andean region. This ecotone condition, combined with the great variety of topographies and substrates present, represents a relevant feature from a botanical point of view. It is possible to find a wide variety of flora, including marginal elements from the aforementioned floristic districts and a significant number of endemic species, such as Sporobolus mendocinus Méndez and Adesmia glandulifolia Steibel and Ulibarri (Prina et al. 2003) (Fig. 18).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	description	Figures 12, 13, 14, 15, 18, Tables 5, 6	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	diagnosis	Diagnosis. Euathlus susanae sp. nov. can be distinguished from all known congeners by the following combination of characters: tibial apophysis with two robust branches, the PB shorter than the RB and both bearing strong internal spines, males with a palpal organ similar in general morphology to that of E. condorito, but it can be distinguished by a more developed prolateral inferior keel (PI) with stronger and distally serrated teeth (Figs 12 D, 13). Females are diagnosed from congeners by their spermathecae, which consist of two wide seminal receptacles projecting straight upward, each with pronounced inner lobes and two large semi-spheroid lateral chambers pointing upwards (Fig. 14 D, E).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	description	Description male. Male holotype (UNS M 1078). — Coloration (in alcohol): carapace dark brown with small grey and black setae and long golden setae more abundant on the margins and on dorsal chelicerae (Fig. 12 A); legs brownish; abdomen with black setae and long orange setae and a large patch of orange setae on the anterior-dorsal face; sternum, coxa, and trochanter reddish (Fig. 12 B, C). — Coloration (in life): Orange hairs on legs, margins of carapace, chelicerae, and proximal abdomen. Ventral body with dark brown / black coloration (Fig. 15 D, E). Total length 28.97. — Prosoma: Carapace length 12.32, width 11.32. Anterior eye row slightly procurved, posterior one recurved. Eye sizes and interdistances: AME 0.31, ALE, 0.59, PME 0.34, PLE 0.56, AME - AME 0.31, AME - ALE 0.19, PME - PME 0.75, PME - PLE 0.13, ALE - PLE 0.19, OQ length 1.41, width 1.75, clypeus 0.31. Fovea transverse, straight, width 1.33. Labium length 1.56, width 2.06, with 76 cuspules. Maxillae (right / left) 144 / 151 cuspules. Sternum length 6.11, width 5.55 (Fig. 12 B). Right chelicerae with 7 well-developed teeth on promargin of furrow and 9 small teeth on the proximal area of furrow, left chelicerae with 7 well-developed teeth and 1 small located distally on the promargin of furrow and 9 small teeth on the proximal area of furrow. — Appendages: Tarsi I – IV densely scopulated, undivided. Metatarsi I fully scopulated, II 1 / 2 scopulated, III 1 / 3, IV 1 / 4 apically scopulated. Leg and palpal segments lengths in Table 5. Spination: Femora and patellae of palps and legs I – IV, tarsi of palp and legs I – IV, 0. Femora: II 1 - 3 - 1 P, III 1 - 1 - 1 - 1 P. Tibiae: palp 2 - 2 V, 1 - 2 P; I 2 - 1 - 1 V, 1 - 1 P; II 3 - 2 - 3 V, 1 - 1 P; III 2 - 2 - 3 V, 1 - 1 P, 1 - 1 R; IV 2 - 2 - 2 V, 1 - 1 P, 1 R. Metatarsi: I 1 - 1 V; II 1 V; III 1 - 1 - 2 V, 1 - 1 - 1 P, 1 - 1 - 1 R; IV 1 - 1 - 1 V, 1 - 1 - 1 - 1 P, 1 - 1 R. Metatarsus I slightly curved. Tibial apophysis of legs I with two short well-developed branches, retrolateral branch slightly longer than prolateral; PB and RB with an internal subapical strong and short spine (Fig. 12 D). Metatarsi I flexes to the retrolateral branch of the tibial apophysis. — Opisthosoma: Abdomen with oval central urticating setae patch with types III and IV. Four spinnerets, PMS 1.1 long and PLS three segmented, basal segment 2.1 long, medial segment 1.2 long and apical segment 1.5 long. — Genital organs: Palpal organ piriform without constriction between tegulum and embolus. Embolus curving retrolaterally, prolateral keels unequal; PS flat and less developed, PI well developed with 6 – 9 small teeth along the retrolateral face of the curvature of embolus (Fig. 13).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	description	Description female. Female paratype (UNS M 1396). — Coloration (in alcohol): Carapace dark brown covered with black and grey short hairs and golden long hairs which are more abundant on the margins and on dorsal chelicerae (Fig. 14 A), legs brownish with evident patellar lines, abdomen dark brown with short black hairs and long golden hairs on the dorsum; sternum, coxa and trochanter light brown (Fig. 14 B, C). — Coloration (in life): Iridescent orange to pink hairs at the base of the legs, chelicerae, and carapace. Longer pink hairs on the legs, margins of the carapace, and distal abdomen. The proximal abdomen is covered with long orange hairs. The ventral face of body is very dark, almost black (Fig. 15 C, E). Total length 36.63. — Prosoma: Carapace length 13.88, width 12.65. Anterior eye row procurved, posterior one recurved. Eye sizes and interdistances: AME 0.31, ALE 0.63, PME 0.41, PLE 0.50, AME - AME 0.47, AME - ALE 0.13, PME - PME 0.88, PME - PLE 0.13, ALE - PLE 0.19, OQ length 1.47, width 2.09, clypeus 0.34. Fovea transverse, straight, width 1.35. Labium length 1.67, width 2.78 with 125 cuspules. Maxillae (right / left) with 137 / 139 cuspules. Sternum length 8.33, width 6.66 (Fig. 14 B). Right chelicerae with 8 large teeth on promargin of furrow and 6 small teeth on the proximal area of furrow, left chelicerae with 7 large teeth on the promargin of furrow and 6 small teeth on the proximal area of furrow. — Appendages: Tarsi I – IV densely scopulated, undivided. Metatarsi I 3 / 4 scopulated, II 2 / 3 scopulated, III 1 / 3 scopulated, IV 1 / 4 apically scopulated. Legs and palpal segments lengths in Table 6. Spination: Femora and patellae of legs I – IV, patellae of palps, 0. Femora of palp: 1 P. Tibiae: palp 2 - 2 - 3 V, 1 R; I 2 V; II 1 - 2 V; III 2 - 1 - 2 V, 1 P; IV 2 - 2 V, 1 - 1 P. Metatarsi: I 1 V; II 1 - 1 V; III 2 - 1 - 2 V, 1 - 1 - 1 P, 1 - 1 - 1 R; IV 1 - 1 - 2 - 3 V, 1 - 1 - 1 - 1 P, 1 - 1 R. — Opisthosoma: Abdomen with large “ apple ” shaped urticating setae patch with types III and IV. Four spinnerets, PMS 1.2 long and PLS three segmented, basal segment 2 long, medial segment 1.6 long, and apical segment 1.3 long. — Genital organs: Spermatheca with wide seminal receptacles, upper margin smooth, with pronounced oval margins towards the inner part, and with two semi-spheroid lateral chambers pointing upwards (Fig. 14 D, E).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	etymology	Etymology. This species is a noun in the genitive case, named after Susana Seen, the mother of the collector, whose unconditional support made the discovery of this species possible.	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
76F07C38F6175A4282C30D602CED2CE9.taxon	distribution	Distribution and natural history. This species is distributed in northwestern La Pampa province and southeastern Mendoza province. Euathlus susanae sp. nov. was found in the Protected Provincial Area Cerro Negro, La Pampa province (Fig. 15 A), and in the locality of Agua Escondida, Mendoza province (Fig. 18). The Cerro Negro reserve contains the “ Cerro Negro ”, which is a basaltic volcano dated from 4.71 Ma that elevates 1167 m a. s. l. and its summit represents the highest geographical point in La Pampa province (Bertotto et al. 2022). The volcano is surrounded by a middle altitude steppe, located in the center of the Monte biogeographical province (elevation of about 1100 m), which is dominated by Larrea divaricata Cav. 1800. The specimens of Euathlus susanae sp. nov. were found in burrows and shelters under vesicular volcanic agglomerates. One adult female and two immature males were found in October (spring in the southern hemisphere). The immature males molted three months after capture, in late February (summer in the southern hemisphere). Individuals from Agua Escondida (Fig. 15 B), were found in burrows and shelters under rocks of the Agua Escondida Formation, composed by quartz sandstones of Upper Carboniferous age (elevation of about 1095 m) (González Díaz 1972), also located in the Monte biogeographical province.	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
00FBD712397953D888B90F43108BE2A9.taxon	description	Figures 16, 17, 18, Table 7	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
00FBD712397953D888B90F43108BE2A9.taxon	description	Description female. Female (MACN - Ar 47712). — Coloration (in alcohol): reddish brown, two yellowish lines on femora, patella, and tibia of palps and legs I-IV. Total length 25.52. — Prosoma: Carapace length 10.60, width 9.46 (Fig. 16 A). Anterior eye row procurved, posterior one recurved. Eyes sizes and interdistances: AME 0.16, ALE 0.31, PME 0.12, PLE 0.39, AME - AME 0.42, AME - ALE 0.16, PME - PME 0.74, PME - PLE 0.08, ALE - PLE 0.23, OQ length 1.19, width 1.60. Clypeus absent. Fovea transverse, slightly procurved, width 1.55. Labium length 1.46, width 1.73 with 91 cuspules. Sternum length 4.87, width 4.56 (Fig. 16 B). Chelicerae with 6 well-developed teeth on promargin of furrow and 7 teeth on the proximal area on retromargin. — Appendages: Tarsi I – IV densely scopulated and entire. Metatarsi I fully scopulated, II 2 / 3 scopulated, III 1 / 2 scopulated, IV 1 / 4 apically scopulated. Leg and palpal segments lengths in Table 7. Spination: Femora, patellae, and tarsi of palps and legs I – IV, 0. Tibiae: palp 0 - 0 - 0 - 2 (ap) V, 1 - 0 - 1 - 1 (ap) P; I 0 - 0 - 1 - 2 (ap) V, 0 - 0 - 0 - 1 (ap) P; II 0 - 1 - 0 - 3 (ap) V; III 0 - 1 - 0 - 3 (ap) V, 0 - 0 - 1 - 0 P; IV 0 - 1 - 0 - 0 V, 0 - 1 - 0 - 1 (ap) P, 0 - 1 - 1 - 1 (ap) R. Metatarsi: I 1 - 0 - 0 - 1 (ap) V; II 0 - 1 - 0 - 0 V; III 1 - 2 - 0 - 3 (ap) V, 0 - 1 - 0 - 1 P, 0 - 0 - 0 - 1 R; IV 1 - 2 - 1 - 3 (ap) V, 0 - 1 - 0 - 1 P, 1 - 1 - 3 - 1 R. — Opisthosoma: Types III and IV urticating setae present. Four spinnerets, PMS 0.92 long and PLS three segmented, basal segment 1.94 long, medial segment 1.26 long and apical segment 1.12 long. — Genital organs: Spermatheca consisting of two high seminal receptacles, sub-quadrate, with upper margin not straight, with a few small mounds; each with a lateral wide oval chamber connected with a wide duct (Fig. 16 D).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
00FBD712397953D888B90F43108BE2A9.taxon	distribution	Distribution. Previously known from the Huiliches Department, Neuquén province, Argentina. The species has been recorded near Curruhué Chico Lake (type locality) (Ferretti 2015). From this work, recorded in Junín de los Andes, Neuquén province (Fig. 18).	en	Allegue, Maite, Peralta-Seen, Nicolás, Ferretti, Nelson (2025): Integrative systematics of the tarantulas Euathlus Ausserer, 1875 from Argentina: cladistics, molecular phylogeny and new species (Araneae: Theraphosidae). Arthropod Systematics & Phylogeny 83: 713-736, DOI: 10.3897/asp.83.e171040
