Tityus ( Atreus ) icarus, Laborieux, 2024

Tityus ( Atreus) icarus View in CoL sp. n.

( Fig. 1 -29)

ZooBank: https://zoobank.org/ 4C929DEF-DF70-4DFC-A043-9DC609B81F69

Holotype, ♀, Colombia, Cundinamarca, La Vega, Estacion Experimental JCM ( 4.955239, -74.379291), 1350m a.s.l., 20/XII/2023, Léo Laborieux, deposited at the Museo de Historia Natural C.J. Marinkelle (Universidad de los Andes). Catalog number:ANDES-IN-8785. GoogleMaps

Paratypes, 1 ♂ & 1 ♀, Colombia, Cundinamarca, La Vega, Estacion Experimental JCM ( 4.955239, -74.379291), 1350m a.s.l., 20/XII/2023, Léo Laborieux, deposited at the Museo de Historia Natural C.J. Marinkelle (Universidad de los Andes). Catalog numbers: ANDES- IN-8786, ANDES-IN-8787 GoogleMaps .

Etymology. – The specific epithet refers to Greek mythology’s Icarus, in memory of multiple instances where individuals engaged in thanathosis during collection, falling from their tree and narrowly missing the author.

Diagnosis. –Scorpion of intermediate size for the subgenus, with the female holotype measuring 75,1 mm in total length (78,9 mm and 72,6 mm for male and female paratypes, respectively). General coloration blackish; pectines pale yellow and basitarsi/telotarsi pale brown. Mesosoma:one centrallongitudinal carina on II-VII, particularlyvisible onIII-VII.Intercarinalspacesweakly granular. Pectineswith 20-20 teeth in female holotype (19- 18 in male paratype). Basal middle lamellae dilated. Pectinal basal piece without a glandular region. Metasoma: all carinae moderately crenulate and weakly raised, setation weak.Lateral carinae of metasomal segment II represented by 1+3-4 granules occupying its distal quarter in female holotype (distal third in male paratype). Posterior granules on the dorsal carinae of segments I and II small and spinoid. Segments III-V without any prominent spinoid granules.Chela with black fingers.Movable fingers with 16-16 oblique rows of denticles. Marked secondary sexual dimorphism at the adult stage, especially in pedipalps with femur, patella and chela length/width ratios 5.29, 4.03 and 8.95 respectively in male and 2.82-3.03, 2.37-2.44 and 4.43-4.78 respectively in females. These morphometric values sit between those of closely related species ( T. ( Atreus) antioquensis , T. ( Atreus) nematochirus ) and those of T. ( Atreus) asthenes Pocock, 1893 , whose pedipalps are more robust (Lourenço, 2000). Ventral telotarsal macrosetae of leg pairs I-IV distributed in an irregular tuft (type I).

Description (based on female holotype and male paratype)

Coloration. – Very dark scorpion at the adult stage, as is often the case in subgenus Atreus . Coloration almost uniformly dark brown, sometimes with a purplish sheen under strong white light. Dorsal faces of metasomal segments slightly lighter than the rest, with a reddish hue. Venter of the same dark color as the rest of the body; pectines pale yellow. Telotarsi and distal extremities of basitarsi pale brown on all locomotory legs. Chela fingers completely black. Chelicerae black with dark red teeth. Important developmental change in coloration, with young individuals exhibiting a variegated, dominantly pale-brown coloration ( Fig. 29)

Morphology. – Carapace weakly granular, with the anterior margin presenting a moderate median concavity. Furrows moderately deep. Median ocular tubercle in a distinctly anterior position, with eyes separated by 1.5 ocular diameter and moderate, crenulate median ocular carinae becoming subcrenulate over the eyes. Three pairs of lateral eyes, half the diameter of the median eyes. Sternum subtriangular. Mesosoma: one central longitudinal carina on II-VII, strongly crenulate. Represented by one row of granules on II; by one row anteriorly and two rows posteriorly on III-VI; by two rows of granules on VII. Segment VII pentacarinate, with central longitudinal carina in anterior third; lateral and paramedian carinae joined proximally by a series of vertically organized granules. Tergites I-VI with granular transversal carinae; mostly fused to posterior margins on I-II, only becoming distinct laterally; distinct and doubled on III-VI. Intercarinal spaces weakly granular on all tergites. Venter with genital operculum split longitudinally; valves subtriangular. Pectines: pectinal tooth count 20-20 (19- 18 in male paratype). Basal pectinal piece without a glandular region. Basal middle lamellae dilated. Sternites I-VI almost smooth; VII weakly granular. Flattened triangle on the posterior margin of III smooth. Sternite V with 2+2 longitudinal keels, i.e. (i) 2 moderately crenulate paramedian keels on distal half and (ii) 2 moderately to strongly crenulate lateral keels on central third. Spiracles oblique, elongated. Metasoma: all carinae moderately crenulate and feebly raised. Setation weak. Segment I decacarinate. Segment II with 8 carinae and 2 lateral carinae occupying its distal quarter (distal third in male paratype), represented by 1 + 3-4 granules. Segments III and IV with eight carinae. Segment V pentacarinate, in addition to vestigial paramedian ventral carinae, visible proximally. Posterior granules of dorsal carinae small and spinoid on segments I and II; same size and shape as the rest of the granules on III-V. Intercarinal spaces weakly granular in all segments. Median dorsal depression narrow and relatively deep. Telson weakly to moderately granular ventrally, smooth dorsally. Aculeus as long as vesicle, strongly curved. Subaculear tooth strong, spinoid. Cheliceral dentition characteristic of family Buthidae as defined by ( Vachon, 1974). Trichobothrial pattern type A; orthobothriotaxic as defined by ( Vachon, 1974). Dorsal trichobothria of femur arranged in α (alpha) configuration ( Vachon, 1975). Trichobothria d2 on internal face of femur (emigrated from dorsal face). Pedipalps with moderate setation. Femur and patella with some macrosetae distributed along the carinae on all faces. External and dorsal sides of chela manus with short setae; ventral side almost devoid of setation. Fingers with short macrosetae, more dense distally. Femur with 5 strongly crenulate and raised carinae composed of large granules; granules strong and spinoid on internal carina (all weaker in male paratype); ventral face acarinate. Patella with seven raised and crenulate carinae; dorsal internal carina with several very strong spinoid granules, especially proximally. Chela manus with 9 raised and strongly crenulate carinae. Intercarinal spaces weakly granular on femur and patella (almost smooth in male paratype); granular on chela manus (weakly granular in male paratype). Movable fingers with 16-16 rows of oblique denticles and strong, spinoid posterior and anterior granules. Telotarsi of leg pairs I-IV with a tuft of irregularly distributed setae (type I).

Comparisons. – T.icarus sp. n. shows affinities with the Colombian species T.nematochirus and T. antioquensis , with a generally blackish coloration, marked sexual dimorphism (elongate pedipalp segments and chela in males), and an absence of spinoid posterior granules on the dorsolateral keels of metasoma segments I-IV. The new species can however be distinguished from these two taxa based on several key characters:

- T. nematochirus

( i) larger overall size with the male holotype measuring 95 mm (78,9 mm for T. icarus sp. n., male paratype)

( ii) lateroventral carinae of metasomal segment II occupying its distal fifth (distal third/quarter in T. icarus sp. n.)

( iii) higher pectinal tooth count with 21-22 pectinal teeth in male holotype (19- 18 in T. icarus sp. n. male paratype)

( iv) 17 rows of denticles on movable chela finger ( 16 in T.icarus sp. n.)

( v) patella with no spinoid granules (several on the inner face of the patella in T. icarus sp. n.)

( vi) reported absence of a median dorsal depression on metasomal segment V (present and relatively deep in T. icarus sp. n.)

( vii) slenderer pedipalps in male holotype with length/width ratio of femur, patella and chela 9.47, 7.91 and 15 respectively (5.29, 4.03 and 8.95 respectively in T. icarus sp. n. male paratype)

(viii) longer pedipalps in male holotype with pedipalp length/total length ratio 0.67 ( 0.59 in T. icarus sp. n. male paratype)

( ix) other morphometric values ( Table 1).

1

cm

1 - 2. ♀ holotype. 1. Dorsal. 2. Ventral. 3 -4. ♂ paratype. 3. Dorsal. 4. Ventral.

- T. antioquensis View in CoL

( i) reddish coloration, as opposed to the very dark, almost black coloration of T. icarus View in CoL sp. n.

( ii) less dilated pectine basal middle lamellae

( iii) lower pectinal tooth count with 16-16 pectinal teeth in male holotype (19- 18 in T. icarus sp. n. male paratype)

( iv) 14-15 rows of denticles on movable chela finger ( 16 in T.icarus sp. n.)

( v) slenderer pedipalp femur in both sexes with length/width ratio 6.66 in male holotype and 3.72 in female paratype, compared to 5.29 (male) and 2.82-3.03 (female) in T. icarus sp. n.

( vi) slenderer pedipalp patella in both sexes with length/width ratio 6.56 in male holotype and 3.14 in female paratype, compared to 4.03 (male) and 2.37-2.44 (female) in T. icarus sp. n.

(vii) slender chelae in both sexes withlength/widthratio 11.3 inmale holotype and 5.29 in female paratype, compared to 8.95 (male) and 4.43-4.78 (female) in T.icarus sp. n.

(viii) other morphometric values ( Table 1).