Neoscotolemon tancahensis Pérez-González & Mamani & Proud 2025, comb. nov.
Creators: name: Pérez-González, Abel
name: Mamani, Vanesa
name: Proud, Daniel N.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Opiliones
Neoscotolemon
Neoscotolemon tancahensis

description: Neoscotolemon tancahensis (Goodnight & Goodnight, 1951) comb. nov., stat. prom.
(Figs 29–35, Table 5)
Stygnomma spinifera tancahensis Goodnight & Goodnight 1951: 13, figs 13–14; 1953: 177, fig. 5; 1977: 148, figs 12–16. Stygnomma spiniferum tancahense: Kury & Cokendolpher 2000: 155; Kury 2003: 236.
Type material: Holotype: Major ♂ (AMNH, examined), MEXICO, Quintana Roo, Tancah, near the Mayan ruins of Tulum, 12-Aug-1949, C. & M. Goodnight leg. Paratypes: 1 major ♂ (photo voucher), 1 ♀ (photo voucher) (AMNH, examined), with the same data as the holotype. • 1 ♀ (AMNH, examined), MEXICO, Quintana Roo, 12- Aug-1949, Goodnight leg. • 3 major ♂, 5 minor ♂, 8 ♀ (AMNH, examined), MEXICO, Quintana Roo, Island of Cozumel, 16-Aug-1949, C. B. Goodnight leg.
Other material examined: 1 major ♂, 2 ♀ (AMNH), MEXICO, Quintana Roo, Cozumel, Chancanab [sic., should be Chankanaab], 8-Aug-1949, C. B. Goodnight leg. • 1 major ♂ (CNAN-Op000106), MEXICO, Quintana Roo, Isla Mujeres, 4-Apr-1979, J. Palacios leg. • 1 major ♂ (SEM voucher), 1 minor ♂, 2 ♀ (USNM), MEXICO, Quintana Roo, Coastal forest outside Tulum, [20.21098°, -87.43149°], 30-Jul-2014, Team CarBio leg. • 2 minor ♂ (one photo voucher), 1 ♀ (AMNH), BELIZE, Glover’s Reef, Southeast Cay, Southwest Cay. 25-Jul-1971, M. Goodnight leg. • 1 minor ♂, 1 ♀ (AMNH), BELIZE, Glover’s Reef, Southeast Cay, Southwest Cay, 25-Jul-1971, M. Goodnight leg.
Comparative diagnosis. Major males of Neoscotolemon tancahensis differs from males of all other species of Neoscotolemon (except from major males of N. spinifer) by the presence of enlarged setiferous pointed tubercles in each lateral region of free tergite III (Figs 29A; 30A; 31A). Additionally, N. tancahensis can be distinguished from N. pictipes by having, in males, the anal operculum covered by pointed setiferous tubercles (Figs 30B; 31B–D vs. Fig. 2B, D, F, G). Neoscotolemon tancahensis is easily distinguished from males of N. armasi by the absence of a pseudochela in the enlarged tarsus of the pedipalp (Figs 30E, F; 32A, B vs. Fig 8E). Neoscotolemon tancahensis can be differentiated from the most morphologically similar species, N. spinifer, by the absence of the medial long pointed setiferous tubercles on free tergites I– III as is exhibited in N. spinifer. Furthermore, the dorsal surface of the pedipalp tibia in N. tancahensis is smooth, contrary to N. spinifer, which is covered by scattered granules (Figs 30E, F; 32A, B vs. Figs 23D, E; 25A, B).
Description. Major male (holotype, AMNH; paratype AMNH; USNM). Body measurements: Total body length 3.14, carapace length 1.11, scutum magnum length 2.64, carapace maximum width 1.57, abdominal scutum maximum width 2.28. Appendage measurements in Table 5.
Dorsum: Outline slightly hourglass-shaped with an Eta (η) shape, with a constriction at eye level (Figs 29A; 30A; 31A). Carapace granulated, wider than long, with a rounded frontal hump; anterior border slightly convex, each lateral side with a row of small tubercles (Figs 30A; 31A). Cheliceral sockets not marked (Fig. 31A). Eyes separated, slightly posterior to the medial region of the carapace, located at the base of a poorly defined ocularium with a wide base and apically armed with a long, slightly forward-slanted spiniform apophysis with setiferous granules on the base; ocularium extends from the posterior of the carapace to just before the frontal hump (Figs 29C; 30B; 31D, E). Abdominal scutum in lateral view convex (Figs 29C; 30B; 31D). Sulcus I deep and well-marked, in dorsal view curved to the posterior body region (Figs 29A, C; 30A, B; 31A, D, E). Mesotergal areas coarsely granulated and not well defined. Mesotergal areas I–II with conspicuous small medial conical setiferous granules; mesotergal areas III–IV with two rows of conspicuous small conical setiferous granules, with medial granules slightly longer than lateral ones (Figs 30A, B; 31A, D). Mesotergal area V with a posterior row of small conical setiferous granules (Figs 30A, B; 31A, D). Lateral borders with two rows of granules, the inner row consisting of setiferous granules (Fig. 31A, D). Ozopore with an oval, narrow, and elongated orifice with a descending channel extending toward the posterior region (Fig. 31D). Free tergites granulated; free tergites I–II with a posterior row of conical setiferous granules; free tergite III with a posterior row of setiferous tubercles, lateral tubercles slightly longer than medial tubercles (Figs 30A, B; 31A, D).
Venter: Coxae I–IV with sparse setae and small granules (Fig. 31B); coxae I–II with setiferous granules; anteroposterior borders of coxa III with a row of strong granules connecting with coxae II and IV, respectively (Fig. 31B); posterior border of the spiracular area and free sternites I–V with a row of setiferous granules (Figs 30B; 31B–D); anal operculum with setiferous granules and long conical tubercles (Figs 30B; 31B–D). Spiracles not concealed (Fig. 31B).
Chelicerae: Basichelicerite unarmed, with an elongated and slightly marked bulla (Figs 30C, D; 32C, D). Cheliceral hand with sparse setae and small frontal setiferous granules (Figs 30C, D; 32C–E). Fixed finger with a proximal big conical tooth; movable finger distally with a row of rounded teeth (Fig. 32E).
Pedipalps: Coxa elongated (i.e., remarkably longer than trochanter), with one small proximal dorsomesal protuberance and two ventroectal setiferous granules (Figs 31A, B). Trochanter rounded, with three dorsal and one mesal pointed setiferous tubercles; ventrally with three setiferous granules (Figs 30E, F; 31B; 32A, B). Femur dorsally convex; ventrally armed with a row of six small ectal setiferous pointed tubercles, the fifth distal tubercle longest (Figs 30F; 32B); ventroproximally armed with two large spines, fused at the base (Figs 30E, F; 32A, B); ventromesal surface with a medial spine followed by one setiferous pointed tubercle (Figs 30E; 32A). Patella short, ventrodistally with one mesal spine and one small ectal setiferous tubercle (Figs 30E, F; 32A, B). Tibia ventromesally with three small spines, increasing in size from proximal to distal (Figs 30E; 32A); ventroectally with one proximal setiferous tubercle, followed by one spine, one setiferous pointed tubercle, and distally two spines fused at the base; the longest spine featuring a socket with an apical square-shaped projection (Figs 30F; 32B); ventral surface with a few small granules (Figs 30E; 32A). Tarsus remarkably elongated, incrassate, and ventrally flattened (Figs 29C; 30E, F; 32A, B); ventromesally with one proximal setiferous pointed tubercle, followed by a row of five spines, the second and fifth spines largest (Figs 30E, 32A); ventroectally with one proximal setiferous tubercle and three spines interspersed with four setiferous pointed tubercles, two tubercles between the two most distal spines (Figs 30F). Claw remarkably short, robust, and triangular (Fig. 30E, F).
Legs: Coxae II and IV with setiferous granules on dorsolateral surface (Fig. 31A, D). Trochanters I–IV with setiferous granules. Femurs I–IV with sparse setiferous granules; femurs I–II with one longitudinal row of ventral setiferous tubercles; femurs III–IV with one prolateral and one retrolateral longitudinal row of setiferous tubercles (Fig. 29B, C). Metatarsus III swollen at calcaneus region, in lateral view with a rectangular shape (Fig. 33A); calcaneus extends from the medial region of the metatarsus (Fig. 33A), ventrally with trichomes and some lateral sensilla chaetica (Fig. 33A, B); apical region of calcaneus with a concentration of acuminate trichomes densely covering numerous aggregated pores (glandular openings) (Fig. 33A, C). Tarsi III–IV without scopula and modified spatulate setae (Fig. 33D). Tarsal formula: 4(2):8–9(3):5:5.
Color (specimen preserved in 80% ethanol): General body appearance yellowish-brown; appendages light yellowish-brown (Fig. 29A–C); coloration at the chelicerae insertion level lighter, creating a false appearance of a marked cheliceral socket (Fig. 29A). Free sternites I–IV darker yellowish-brown (Fig. 29B).
Genitalia: General shape of penis tubular, with a distal constriction and widening apically to a blunt, rectangular tip; boundary not well defined between pars basalis and pars distalis (Fig. 34A, C). Pars distalis with a ventral plate ending in a deep calyx (Fig. 34B, E); calyx dorsally open with two thin laminar projections (wings) (Fig. 34B, E); dorsally, pars distalis with a medial shallow neckline (Fig. 34B, E). Pars distalis armed with two groups of macrosetae arranged bilaterally: a basal row of four pairs (B1–B4) extending along the edge, from the dorsal neckline to the ventrolateral region (Fig. 34B, D–F), and an apical row (A1–A3) located on the ventrolateral region of the calyx (Fig. 34D, F, G). On one side there is a fourth apical macroseta that is considered teratological (Fig. 34F). Capsula externa with follis invaginated and not visible in resting position (Fig. 34B, E). Capsula interna with two laminar conductors that are arrow-shaped apically (i.e., medially pointed and with two lateral projections) (Fig. 34B, D–F); conductors flank a shorter, pointed, laminar stylus (Fig. 34B, D, E).
Minor male (AMNH). Body measurements: Total body length 2.43, carapace length 0.83, scutum magnum length 2.07, carapace maximum width 1.23, abdominal scutum maximum width 1.75. Appendage measurements in Table 5. Minor male differentiated from major male by the presence of small setiferous granules on free tergite III and anal operculum similar to that of the female, and in contrast to the long setiferous tubercles found in major male (Goodnight & Goodnight 1977, figs 12; 14; 16; herein Fig. 35D, E vs. Fig. 35A, B, G, H). Minor male also differs from major male in having a shorter pedipalp with small spines. Pedipalp trochanter bears small setiferous tubercles; tibia lacks ventral tubercles; tarsus is neither elongated nor enlarged, mesal surface of tarsus with a proximal setiferous tubercle followed by four spines whereas major males possess five spines; claw remarkably longer, thin, and pointed similar to that of female (Goodnight & Goodnight 1977, figs 12, 16; herein Fig. 35E vs. Fig. 35A, H). Metatarsus III similar to major male (Fig. 35F). Tarsal formula 4(2):7(3):5:5.
Female (paratype,AMNH). Body measurements:Total body length 2.89, carapace length 0.85, scutum magnum length 2.06, carapace maximum width 1.25, abdominal scutum maximum width 1.95. Appendage measurements in Table 5. Resembles minor and major males in the armature of scutum magnum but differs from major males by having setiferous granules on free tergite III and anal operculum in contrast to the long setiferous tubercles in major males (Fig. 35A, B vs. Fig. 35G, H). Female also differs from major male by having a shorter pedipalp and smaller spines, with the trochanter bearing one small dorsal setiferous granule (Fig. 35B vs. Fig. 35H). Tarsus of pedipalp remarkably shorter, with four ventromesal spines like minor male, but differs by the absence of a proximal mesal setiferous tubercle. Claw elongated and pointed similar to that of minor male (Fig. 35B vs. Figs 35E; 35H). Additionally, female differs from both minor and major males by having a metatarsus III not swollen, lacking aggregated pores and associated setae, and without the deep intrusion of the astragalum by the calcaneus (Fig. 35C vs. Fig. 35F, I). Tarsal formula 4(2):8(3):5:5.
Geographical distribution. Mexico: Quintana Roo State —Tancah and Island of Cozumel (Goodnight & Goodnight 1951); Tancah—Cueva de la Avispa (Goodnight & Goodnight, 1977) (Fig. 39). Belize: Glover’s Reef (Goodnight & Goodnight, 1977). New record: Mexico: Quintana Roo, Isla Mujeres (Fig. 39).
Natural history. Goodnight & Goodnight (1951: 14) wrote about N. tancahensis: “At Tancah, these animals were found in large numbers under the fibrous material from the trunks of the coconut palms. These had fallen on the sand. It is possible that the oil of this palm may have attracted the animals. They were found within a few yards of the Caribbean.” Some specimens were collected in Tancah by us (APG) under rocks, in sandy soil, in the dry forest near the beach.
description: Published as part of Pérez-González, Abel, Mamani, Vanesa & Proud, Daniel N., 2025, On the genus Neoscotolemon (Opiliones: Laniatores: Samooidea incertae sedis) with the description of one new species, pp. 109-165 in Zootaxa 5563 (1) on pages 148-154, DOI: 10.11646/zootaxa.5563.1.11, http://zenodo.org/record/14595849