taxonID	type	description	language	source
038F1E10BE465300FF0E5D30FDFBFD02.taxon	discussion	Pessoa-Silva et al. (2021: 105) proposed the synonymy of Gonyleptes bicornis under Sadocus asperatus, seemingly based on Roewer (1913) (they cite ‘ fig. 4 a – b’ in their synonymy; also a non-existing ‘ fig. 4 – 4 b’ in the entry for Sørensen 1902). Pessoa-Silva et al. (2021) based their conclusion on both the original description and the supposed drawings of G. bicornis, i. e., adopting the prevailing usage of considering Gervais’ (1854) fig. 4 as referable to this species. As key features from the original description of G. asperatus (cf. Gervais 1847), to support the synonymy Pessoa-Silva et al. (2021) mention (a) ‘ the spines on the free tergite’, (b) ‘ the two apical apophyses on the TrIV’, and (c) ‘ uneven spines in the inner part of the “ leg ” (referring to FeIV) ’. The comparison between the descriptions of G. asperatus (both the original one, Gervais 1847, and the redescription of Gervais 1849) and that of G. bicornis (Table 2) yielded the following outcomes: (a) Spines on free tergites are described only for G. asperatus; just weak tubercles exist in G. bicornis. (b) The description of Gervais (1847) of G. asperatus does not give enough detail about apophyses on TrIV, and only some resemblance could be extrapolated if Gervais’ (1854) fig. 9 and the description of G. bicornis were taken into account. (c) About FeIV, Gervais’ (1847) description of G. asperatus and Gervais’ (1854) fig. 9 agree in the inner border being armed with strong apophyses; but comparison with G. bicornis is inconclusive. Incidentally, Pessoa-Silva et al. (2021) misinterpreted the word ‘ leg’ (‘ pierna’ in the Spanish text) assuming that Gervais (1849) referred to the femur, when the tibia was actually meant. As a matter of fact, apophyses on ‘ leg’ (tibia) IV provide the best diagnostic feature to assess that G. bicornis is a member of Parabalta. This feature is only indicated in the description of G. bicornis and clearly shown on Gervais’ (1854) fig. 10. Many items exhibit a decided mismatch between the descriptions of G. asperatus and G. bicornis (Table 2); in other features comparison resulted inconclusive (?), and only the paired armature on the ocular mound and the bifid apophysis of CxIV look similar in both (by the way, both character states are actually quite widespread in the family). In sum, G. bicornis did not prove to be a junior synonym of G. asperatus, and has to be revalidated and transferred to Parabalta instead.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE415304FF0E5BFDFD40FEB6.taxon	discussion	Confusion on Gervais’ (1854) plate ‘ Arachnideos N ° 1 ’ affects Gonyleptes planiceps too, another species that had (taxonomically) ‘ crossing destinies’ with G. bicornis. The original description and illustrations of G. planiceps are clear (Gervais 1842) and some early papers demonstrated a good notion of its identity (cf. Simon 1884: 141, 1887: 37, Pl. 2, fig. 9). Problems emerged with a further mismatch between redescription and figures of Gervais (1849, 1854) that (again) puzzled Sørensen and Roewer. Gonyleptes planiceps was treated by Gervais (1849: 24) and was explicitly referred to a line drawing of a male in dorsal view: fig. 10. The redescription is a verbatim translation to Spanish of the redescription of G. planiceps previously given by Gervais (1844). Sørensen (1902) said (translation from Latin): ‘ Whether this species [G. planiceps] belongs to the genus Lycomedes or to another genus, I really do not know. Description and figure [fig. 10] given by Gervais do not agree in any way. According to the description areas are divided by length, what the figure does not show – After the figure, five transverse grooves are present. (…) If the species can be determined, the paired eminences of the free dorsal segments and legs IV (male) would indicate species’. In the same publication, Sørensen (1902) happened to examine a MNHN male labelled “ Pachylus planiceps ” by E. Simon, concluding that it did not agree ‘ with Gervais’ illustration’ [that of 1854 was meant!], but allegedly represented a new species instead, which he described as Balta meridionalis Sørensen, 1902 (pp. 21, 23). This puts in evidence that, despite of being aware of the text / drawings mismatch, Sørensen’s (1902) concept of Gonyleptes planiceps remained attached to Gervais’ (1854) fig. 10. Types: Gervais (1842) did not explicit the original series of G. planiceps, but, as he described both sexes, at least one male and one female were available to him (thus, Roewer’s 1913: 136 statement “ ♀ unbekannt ” [female unknown] is mistaken). During a meticulous survey of the “ dry collection ” in the NHMUK, I discovered one male and one female, pinned separately, undoubtedly belonging to the type series (as syntypes). The original label of the male specifies “ Gonyleptes planiceps Guer. ic. R. A. (type), Magellan ”, that of the female just “ Magellan ”. These specimens had some appendages either lost or loose, so I transferred them to vials with 70 % ethanol, along with suitable labels (handwritten by me) to unequivocally indicate their type status. The labels of the male (NHMUK 013376526) are currently available at the NHM Data Portal: https: // data. nhm. ac. uk / dataset / collection-specimens / resource / 05 ff 2255 - c 38 a- 40 c 9 - b 657 - 4 ccb 55 ab 2 feb / record / 8287232. Pessoa-Silva et al. (2020) took profit on this unpublished information to formally determine the validity of Gonyleptes planiceps as senior synonym of Balta meridionalis, what is in full agreement with my previous observations. Roewer makes it worse: As purported in Roewer’s labels, this author believed that the specimen SMF RI / 795 belonged to the type series of Gonyleptes planiceps (Acosta 1996 a). The catalog-card in the SMF declares its presumed status too: “ Simon ded., ex Museum Paris, 1 ♂ Paratypus! ”. This is likely the MNHN specimen cited by Roewer (1913) as “ Lycomedes planiceps (Guérin) ”, which he seemingly incorporated later to his own collection (Roewer 1923). The morphology of this specimen (a male, initially dry preserved, examined) does not match the original description and illustrations of G. planiceps given by Gervais (1842), neither Gervais’ (1849) redescription; but it does match the male drawn by Gervais (1854) in his fig. 10! That is to say, specimen SMF RI / 795 is actually conspecific with G. bicornis, as restored in this paper (see below). On the one hand, the alleged type status of SMF RI / 795 is not supported (Acosta 1996 a). On the other hand, Roewer followed Sørensen and gave preference to fig. 10 for identification, over the description. Remarks: Roewer (1913) indicated that the MNHN material of Gonyleptes planiceps comes from around the Strait of Magellan, information seemingly inspired by the original description, not stated on any label. There is a second citation of “ Lycomedicus planiceps ”, also by Roewer (1923), where a male from “ Valparaiso ” (allegedly in his collection) is reported. Over several months I thoroughly revised all tubes of Pachylinae and the catalogues of Roewer’s Collection (Acosta 1996 a), but just one specimen labeled as Lycomedicus planiceps was located, the already mentioned RI / 795. Most probably the two citations refer to the same specimen, and the reference to “ Valparaíso ” is another of many inaccuracies in Roewer’s work. On the SMF catalog-card the species name was first written “ planiceps (Guer.), Lycomedes ”, then corrected to “ planiceps (Roewer), Lycomedicus ” (note the mistaken amendment of the authorship). At this point it is needed to test the correspondence between Gervais’ (1854) fig. 10, and the description of Gonyleptes bicornis and redescription of G. planiceps in Gervais (1849); this is accomplished in Table 3, including (when applicable) features of the above mentioned fig. 4 b (Gervais 1854) as well, which I also attribute to G. bicornis. Contrary to the uses of Gervais (1849), Sørensen (1902) and Roewer (1913), fig. 10 does not agree with the redescription of G. planiceps but with the description of G. bicornis instead. The conclusion of this thorough comparison is straightforward: Gonyleptes bicornis is to be referred to two mislabeled illustrations in the Atlas (Gervais 1854): fig. 4 b and fig. 10. They show without doubt a hitherto undetected member of genus Parabalta: henceforth named Parabalta bicornis comb. nov.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE435304FF0E5A04FE77FCF9.taxon	description	urn: lsid: zoobank. org: act: 3 B 890 E 90 - 78 E 3 - 4 E 8 E-A 639 - 0 F 3 F 3437 B 6 F 9	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE435304FF0E5A04FE77FCF9.taxon	type_taxon	Type species. Gonyleptes reedii Butler, 1874, by monotypy.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE435304FF0E5A04FE77FCF9.taxon	distribution	Distribution. South America: Central Chile (Coquimbo, Valparaíso and Metropolitan Regions, between 31 ° 30 ’ S and 33 ° 25 ’ S: Acosta 1996 b and Fig. 3); also found in Juan Fernández archipelago (likely introduced: Pérez-González et al. 2022). Most continental localities lie below 1000 m a. s. l. (Fig. 3). Aside, the known range partially overlaps with that of the ‘ Pachylus chilensis species group’ (cf. Acosta 2021), whereas records of Parabalta reach more northerly.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	description	urn: lsid: zoobank. org: act: 3353 AFE 9 - 7113 - 4 E 68 - ADD 8 - 01 EEF 8 CFAD 5 C Figs. 1 A – F, 2 A – C	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	materials_examined	Type material. Neotype ♂ (MACN-Ar 46511): CHILE, Coquimbo Region, Choapa Province, Cuesta Cavilolén, 30 km NE Los Vilos, 12 November 1987 (E. A. Maury leg.), hereby designated. Qualifying conditions for neotype designation (as required by the ICZN, Art. 75.3). This designation is purposed to guarantee the nomenclatural stability of the revalidated binomen Gonyleptes bicornis, considering that the taxon was repeatedly misidentified by all authorities for more than 170 years, and also affected the taxonomic knowledge of other species treated by Gervais (1849). The analysis of the most significant interpretations (e. g., Sørensen 1902, Roewer 1913, Pessoa-Silva et al. 2021) is given in detail above, where the ‘ exceptional need’ for a neotype is endorsed. The diagnostic features on which the preceding assessment of the description and figures of Parabalta bicornis focused (see e. g., Tables 2 – 3) are readily recognizable in the material studied and in the redescription below, thus giving ‘ evidence that the neotype is consistent with what is known of the former namebearing type from the original description’, as ruled in Art. 75.3.5. Gervais (1849) did not provide a precise original locality, but merely stated ‘ it is found in humid places of the [Chilean] Republic’. However, it is worth noting that one of Claude Gay’s many exploratory trips across the country took him very close to the modern records of P. bicornis in southern Coquimbo (cf. Sagredo Baeza 2010: xix, xxiii and Fig. 3). No author (not even Gervais 1849) stated the existence of types or the location of original specimens of G. bicornis, and my own searches in European collections (NHMUK, MNHN, NHMW, SMF, ZMC, among the most relevant) also resulted negative. The neotype is lodged in MACN-Ar, an outstanding biodiversity collection in South America (fulfilling Art. 75.3.7.). Other materials studied. CHILE, Coquimbo Region, Choapa Province: Cuesta Cavilolén, 30 km NE Los Vilos, 12 November 1987 (E. A. Maury), 7 ♂, 2 ♀, 2 juv. (MACN-Ar 46512), 1 ♂, 1 ♀ (CDA 000.069); same loc., 7 November 1988 (E. A. Maury), 1 ♂, 2 ♀, 2 juv. (MACN-Ar 46513); Quebrada Playa Agua Dulce, 46 km N Los Vilos, 5 – 6 November 1988 (E. A. Maury), 1 ♂, 1 ♀ (MACN-Ar 46514); “ Chile ”, 1 ♂ “ Type ex Mus. Paris ” (SMF RI / 795) - Lycomedes planiceps det. Roewer 1913), not a type indeed (Acosta 1996 a). Type locality. Cuesta Cavilolén, 30 km NE Los Vilos, Province Choapa, Chile (ca. 31 ° 46.26 ’ S 71 ° 18.95 ’ W).	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	distribution	Distribution. Chile, Coquimbo Region: Choapa Province. Records of this species represent the northernmost ones in the genus (Fig. 3).	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	diagnosis	Diagnosis and comparisons. Male Parabalta bicornis comb. nov. are recognized by having a bifid apophysis on CxIV; armature of TrIV consisting of an apical prodorsal finger-like apophysis pointing upwards, and a small ax-like one on the prolateral side; a row of small apophyses following the dorsomedial one on FeIV; two large acute ventral apophyses on patella IV, and the absence of large ventral apophyses between the basal one and the distal group on TiIV. A detailed comparison with Parabalta reedii + P. cristobalia is shown in Table 4 (these two nominal species are closely allied, if not synonyms, so they are entered together in the table).	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	description	Redescription. Measurements and meristics. DS length: ♂ 7.0 – 8.0 mm (mean = 7.5 mm, n = 11), ♀ 7.0 – 7.9 mm (x = 7.5 mm, n = 6). Detailed measurements of the neotype ♂ and a selected ♀: Table 5. Tarsal formula: ♂ 6: 8 – 9: 6: 6 (neotype with 6: 8: 6: 6), selected ♀ 6: 7 – 8: 6: 6. Coloration in ethanol 70 %. General color yellowish to brownish cinnamon, CxIV, TrIV and FeIV of males darker (somewhat more reddish). Males: Dorsum. DS type γR (gamma rotund, coda unrecognizable, embodied by the large, round mid-bulge; Fig. 1 A). Ocular mound with a pair of tall, acute apophyses (Fig. 1 E). Front border with conic granules in a row, scattered on the frontal hump, which is lower than the ocular mound (Fig. 1 F); scutum margin with a row of small round granules from the ozopore up to constriction 1, then vanishing towards area I. Lateral areas elevated, practically smooth beyond area I. Otherwise DS unarmed (Fig. 1 A), faintly rugose on carapace, smooth and shiny on the rest; area I divided, areas I – IV entire. Area V, FT and dorsal anal plate have a row of flat, very faint granules, the paramedian pair slightly larger than the rest (still flat). In some specimens there is a pair of tiny and inconspicuous paramedian granules on areas III – IV as well. Venter (Fig. 1 B). Posterior margin concave; genital and stigmatic segments delimited by faint tegumentary borders, better defined in small specimens and difficult to see in larger ones (as in the Neotype); the genital part, smooth, depressed and lighter in color. Free sternites almost smooth, with row of minute granules, except for the last sternite and the ventral anal plate, which bear round granules, larger on the laterals. Chelicerae. Unarmed, finely rugulose, posterior side of bulla slightly granulous. Pedipalps. Weak, dorsal tegument tenuously rugose. Ventral setigerous tubercles on Tr (one) and Fe (one basal, followed by a row of blunt ones); Fe with a small medial subapical spine. Pedipalp spination: LAT: Ti i _ [Ii •], Ta IiIi – MED: Ti IiIi, Ta IIi. Legs I – III. Unarmed, tegument finely granulous; only a few large proventral apical granules on FeIII. Leg IV. CxIV (Figs. 1 A – C) smooth to very finely granular, with a strong prolateral apophysis directed diagonally (back – and sideward); it is bifid-tipped, with dorsal branch longer, acute and posteriorly inflected, ventral branch tuberous; on the same ridge as the latter, a ventro-medial basal tuberosity. Minute conic retrolateral apophysis, not easily discernible in some larger specimens. TrIV (Figs. 1 A, C) elongated, armed with a strong apical prodorsal apophysis, pointing upwards, S-curved medially and anteriad; a small ax-like prolateral apophysis on the proximal third; retrolateral surface granulous. FeIV (Figs. 1 A – C) granulous, gradually wider from base to apex; substraight with a slight, abrupt inflection between the first and second third. One large acute apophysis, ventro-proximal, inclined to the median line. A prodorsal row limited to the basal third formed by one (single or bifid) or two upwards pointing, moderate apophyses followed by tall granules. Upon the femur inflection, a large retrodorsal apophysis, somewhat shifted medially and slightly diagonal, either horizontal or gently curved downwards; it is continued after a small gap by a variable row of decreasing apophyses, which turn into granules up to an apical, small conic apophysis. Along the distal two thirds of FeIV, pro- and retroventral rows of tubercles to small apophyses, the former ending in a large apical unciform apophysis, the latter in a smaller one. PaIV, ventral side with blunt grains and two apicoventral acute apophyses, the largest one placed on the midline. TiIV sigmoid in lateral view (more accentuated and more slender in larger specimens), it bears a strong basal apophysis, slanted medially, and a distal group of three apophyses arranged in a triangle; in between 2 – 3 minute intermediate tubercles may exist, otherwise there is a large smooth gap (Figs. 1 C – D). MeIV straight, smooth, fairly thicker than tarsus. Penis (Figs. 2 A – C). Trunk subterminally swollen (wider than high), with glans articulated in the same axis. VP sub-rectangular, front margin straight; it is quite flat in lateral view. Lateroapical group of 3 – 4 macrosetae C. Basal group displaced to the swollen sector of trunk, consisting of two large setae (A 1 – A 2) arranged longitudinally and a small B 1 more ventrally. D 1 and E 1 – E 2 minute. Glans with ‘ columnar’ look, it has membranous expansions on the sides; a thick, finger-like DPG curved towards the stylus, as diagnostic for the genus (Acosta 1996 b). Stylus simple and straight, diagonal, devoid of any spination; VPS of similar length and orientation, its tip abruptly bent downwards in a spiny flat expansion. Variability of ♂ (condition found in the neotype marked as * N). FeIV (n = 20): Sub-basal, prodorsal armature with a single conic apophysis (11 / 20, * N- left), two contiguous (3, * N- right), one bifid (5) or several fused in a tuberous stem (1); the brief row of smaller apophyses / tall granules that follows distad is highly variable, decreasing in size either in regular (* N) or irregular fashion; only rarely (3 / 20) a few conic grains proximal to the large apophysis. FeIV (n = 20): Large retrodorsal apophysis, either slender (16 / 20, * N), very thick (2) or smaller than the row that follows (2); it is normally simple (18, * N) or may bear a small subapical branch (2); there are seldom (6 / 20, * N-right) one or more acute granules basal to it. TiIV (n = 20): gap between ventro-basal and distal apophyses either smooth (14 / 20) or with 2 – 3 vestigial tubercles (6 / 20, * N). Some specimens examined of P. bicornis, like SMF RI / 795 though likely not that depicted in fig. 10 (Gervais 1854), bear a pair of minute, quite imperceptible paramedian granules on areas III – IV, easier to discover in lateral view (in dorsal view they may appear not much as lighter dots). In * N these granules are overly undersized, only visible with DS completely dried out (Fig. 1 A). In Roewer’s (1913) redescription and illustration of Lycomedes planiceps the development of those granules was overstated, showing them as conic tubercles. This was much probably to justify the inclusion of the species in Lycomedes (later Lycomedicus), which was diagnosed with area III ‘ armed’. Females: DS type α-K (alpha-keyhole, coda with divergent sides), unarmed. Lateral areas with a marginal row of round flat granules up to constriction 2. Granules on area V and FT larger than in male; on FT-I a pair of larger paramedian flat granules, on FT-II – III they become small acute apophyses (larger on FT-III). CxIV with small acute prolateral apophysis, diagonally divergent; a small retrolateral one hinders the coxal base to completely fuse with the stigmatic segment, leaving a gap. Stigmatic and genital segments clearly delimited by a tegumentary ridge. Free sternites with a row of round granules, larger than in male, especially on the laterals. TrIV with retrolateral side covered by granules. FeIV slightly curved, granose, with a small apical proventral apophysis. PaIV unarmed; TiIV straight, club-shaped, with a minute apical retroventral, spine-shaped apophysis.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
038F1E10BE43530EFF0E58C9FF0CFEEA.taxon	discussion	On the publication dates. Following the current use, the date printed on the front page of volume 4 of the Historia Física y Política de Chile (1849) is here accepted as valid for Gonyleptes bicornis. It should be warned that volumes were not printed and delivered to subscribers in full; instead, tomes were issued in parts as soon as these were ready, meaning that every single part has its own effective date of publication. Parts are what Gay called ‘ entregas’ (= livraisons, releases), consisting of a number of successive gatherings under a temporary cover, intended to be bound later in the final volume. Signatures, i. e., the marks printed to aid the binder in arranging the gatherings in the correct order, can be recognized on the bottom of the first page of each sheet. As a rule, covers of entregas were removed upon binding, save a few exceptional cases in which they were conserved (Johnston 1941). Almost all zoological volumes consisted of four entregas, except for volumes 2 and 4, each formed by three (N. Evenhuis, unpublished, in litt. 2024). For the botanical part, Johnston (1941) determined that the date on the title page on each volume represents the year when the printer began to work on it, not necessarily the date in which it became available; anyway, in most cases the printed year coincides with the date of at least the first entrega (Johnston 1941). This procedure can be generalized to the zoological part as well (Evenhuis 2015). The description of Gonyleptes bicornis, published on pages 21 – 22, falls within the first entrega of volume 4, which spans from page 1 to 188 and comprises 12 gatherings (N. Evenhuis, in litt. 2024). Thus, in this case we can be confident that the date printed on the front matter (1849) is that of G. bicornis; the year is also endorsed by dates extrapolated from other sources by N. Evenhuis (unpublished, in litt. 2024). Dating of plates proved to be especially challenging (Johnston 1941). They were also issued individually, to be bound together at the end, making up the two volumes of the Atlas (Sagredo Baeza 2010). Although plates were delivered together with the entregas, they were not necessarily synchronous with their reciprocal part of text (Johnston 1941). For example, the very first entrega, corresponding to the historical section, was delivered in 1844 along with two zoological plates (Sagredo Baeza 2010), whereas the zoological text itself started being issued just in 1847. As the precise date of plates remains unknown (N. Evenhuis, in litt. 2024), the only choice is to adopt the date printed on the title page of the Atlas (1854). It has been emphasized that the Atlas reveals several inconsistencies, with some copies available in libraries lacking one or more plates, or containing duplicate ones; in some instances, incongruence between the reference in the text and the labels on the plate has been detected (Stuardo Ortiz 1953), as is the case of Gervais’ (1854) ‘ Arachnideos N ° 1 ’. Readers should be also aware of the existence of a second, cheaper edition of the whole work, issued in 1866, in which all plates were printed in black, i. e., no figure was colored.	en	Acosta, Luis E. (2025): Deciphering a Chilean harvestmen enigma: what is Parabalta bicornis (Gervais, 1849) comb. nov. (Opiliones: Gonyleptidae: Pachylinae). Zootaxa 5563 (1): 193-208, DOI: 10.11646/zootaxa.5563.1.13, URL: https://doi.org/10.11646/zootaxa.5563.1.13
