Ammonius Thorell, 1899

Gonzalez-Filho, Hector M. O., Guadanucci, José Paulo L. & Brescovit, Antonio D., 2023, On the genus Ammonius Thorell, 1899 (Mygalomorphae, Barychelidae): description of the female of A. pupulus, a new species and new distribution records, European Journal of Taxonomy 861 (1), pp. 113-131 : 115-116

publication ID	https://doi.org/10.5852/ejt.2023.861.2071
publication LSID	lsid:zoobank.org:pub:B55BECF4-1716-4439-9BD2-E01B457F092E
DOI	https://doi.org/10.5281/zenodo.7737605
persistent identifier	https://treatment.plazi.org/id/039B87BC-FFFA-FFD4-FDEC-F9CF782AE69B
treatment provided by	Felipe (2023-03-15 14:00:12, last updated 2024-11-27 15:35:48)
scientific name	Ammonius Thorell, 1899
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Genus Ammonius Thorell, 1899 View in CoL

Ammonius Thorell, 1899: 10 View in CoL .

Ammonius View in CoL – Simon 1903: 915. — Benoit 1965: 7. — Raven 1985: 113.

Type species

Ammonius pupulus Thorell, 1899 View in CoL , by monotypy.

Diagnosis

Ammonius can be distinguished from the other barychelids by the apical segment of the PLS digitiform ( Fig. 1F View Fig ); compact eye group rectangular in shape ( Figs 1D View Fig , 4B View Fig , 5D View Fig , 9B View Fig ), eye tubercle flat; A. pupulus with eight eyes ( Figs 1D–E View Fig , 4B View Fig , 5D View Fig ); absence of AME in A. benoiti sp. nov. ( Fig. 9B View Fig ); male cymbium unequal, with prolateral lobe inconspicuous and retrolateral lobe strongly projected ( Figs 2 View Fig , 3C–D View Fig , 8C–E View Fig ). Males resemble Pisenor notius Simon, 1889 (see Benoit 1966: figs 24, 26) by the strongly pronounced retrolateral lobe of the cymbium but differ by the lack of a spur on tibia I, and the modified palpal tibia, with a tibial concavity in the ventro-prolateral side of the palp on A. pupulus ( Fig. 3A–B View Fig ), and by the presence of a tibial thorn on the retrolateral side of the palp on A. benoiti ( Figs 8D–E View Fig , 9D View Fig ). Females of the genus can be distinguished from the other genera by the bilobed spermathecae, with the external stalk small and emerging from the basal region of the receptacle ( Fig. 5E View Fig ).

Description

Very small spiders, total length between 3.9–7.3. General coloration yellowish light brown ( Figs 1A–B View Fig , 5A–B View Fig , 8A–B View Fig ). Abdomen dorsally pale without pattern and spinnerets pale with some brown light setae on dorsal side ( Figs 1F View Fig , 8A View Fig ). Carapace ovate ( Figs 1A View Fig , 5A View Fig , 8A View Fig , 9A View Fig ). Thoracic fovea small and straight ( Figs 1A View Fig , 5A View Fig , 8A View Fig ). Clypeus narrow ( Figs 1D View Fig , 4B View Fig , 5D View Fig , 9B View Fig ). Eye tubercle black and flat ( Figs 1D View Fig , 5D View Fig ). Eye group in rectangular shape, anterior and posterior eye rows straight ( Figs 1D View Fig , 4B View Fig , 5D View Fig , 9D View Fig ). Ammonius pupulus with eight eyes ( Figs 1D–E View Fig , 4B View Fig , 5D View Fig ); A. benoiti sp. nov. with six eyes, AME absent ( Fig. 9A– B View Fig ). Labium rectangular, 2–6 cuspules rounded. Maxillae rectangular with 3–20 cuspules on inner corner, maxillary hell reduced. Anterior lobe short, not projected ( Figs 1C View Fig , 4C View Fig , 5C View Fig ). Maxillary lyra absent. Rastellum absent, distal edge of maxilla with thick setae ( Figs 1C View Fig , 5C View Fig ). Intercheliceral tumescence in males absent. Labiosternal groove shallow, flat, with pair of sigilla ( Fig. 4C View Fig ). Book lungs semi-circular, opening elliptical, and book lung combs absent. Plumose clavate trichobothria in two rows on distal half on all tarsi ( Fig. 4D View Fig ). Claws: ITC absent. STC with parallel row of teeth present on lateral edge on males and absent in females ( Figs 4E View Fig , 6A View Fig , 7A View Fig ). Frictional setae present in all tarsi, very evident, longer and inserted below the claw tuft plate ( Figs 4E–F View Fig , 6A–B View Fig , 7A View Fig ). Scopulae: on metatarsi I–II scopulate and absent on metatarsi III–IV; on tarsi I fully scopulate and tarsi II–IV slightly scopulate. Four spinnerets, PMS very small, PLS long with apical segment digitiform ( Fig. 1F View Fig ), with several spigots on apical half ( Fig. 4A View Fig ). Male palpal tibia with a ventral concavity in A. pupulus ( Figs 2E View Fig , 3A–B View Fig ), absent in A. benoiti . Tibial thorns on the retrolateral side of the palp in A. benoiti ( Figs 8D–E View Fig , 9D View Fig ). Tibial spur absent. Megaspine on the tibia I in A. benoiti ( Figs 8J View Fig , 9E View Fig ). Male palpal bulb with globose subtegulum, with thin and sinuous embolus in A. pupulus ( Fig. 2A–G View Fig ), and slightly curved embolus in A. benoiti ( Fig. 8F–I View Fig ). Spermathecae with two straight receptacles, external receptacle with globose lobe, emerging from the internal receptacle ( Fig. 5E View Fig ).

Included species

Ammonius pupulus Thorell, 1899 ; A. benoiti sp. nov.

Distribution

Cameroon and Ivory Coast ( Fig. 10 View Fig ).

References

Benoit P. L. G. 1965. Les genres des Barychelidae-Leptopelmatinae africains (Araneae - Orthognatha). Revue de Zoologie et de Botanique africaines 72: 72 - 78.

Benoit P. L. G. 1966. Les Barychelidae-Barychelinae africains et malgaches (Aran. - Orthogn.). Revue de Zoologie et de Botanique africaines 74 (3 - 4): 209 - 241.

Raven R. J. 1985. The spider infraorder Mygalomorphae (Araneae): cladistics and systematics. Bulletin of the American Museum of Natural History 182: 1 - 180. Available from http: // hdl. handle. net / 2246 / 955 [accessed 8 Feb. 2023].

Simon E. 1903. Histoire naturelle des Araignees. Deuxieme edition, tome second. Roret, Paris. https: // doi. org / 10.5962 / bhl. title. 51973

Thorell T. 1899. Araneae Camerunenses (Africae occidentalis) quas anno 1891 collegerunt Cel. Dr. Y. Sjostedt aliique. Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar 25 (4, 1): 1 - 105. Available from https: // www. biodiversitylibrary. org / page / 13682607 [accessed 8 Feb. 2023].

Figures

Fig. 1. Ammonius pupulus Thorell, 1899, holotype, ♂ (NHRS-GULI37848). A. Habitus dorsal. B. Habitus ventral. C. Maxillae and labium, ventral view. D–E. Eye group. D. Dorsal view. E. Detail of the eye arrangement. F. Abdomen, lateral view. Scale bars: A–B, F = 1 mm; C–E = 0.5 mm.

Fig. 4. SEM micrographs of Ammonius pupulus Thorell, 1899, ♂ (RMCA 227221). A. Apical segment of PLS. B. Eye group, lateral view. C. Maxillae and labium, ventral view. D. Clavate trichobothria. E. Apical of the tarsus I, lateral view. F. Detail of frictional setae, lateral view. Abbreviations: Ch = chemosensory setae; CT = claw tufts; FS = frictional setae; STC = superior tarsal claws. Scale bars: A, F = 50 µm; B = 300 µm; C = 500 µm; D = 5 µm; E = 100 µm.

Fig. 5. Ammonius pupulus Thorell, 1899, ♀ (RMCA 227221). A. Habitus dorsal. B. Habitus ventral. C. Maxillae and labium, ventral view. D. Eye group, dorsal view. E. Spermathecae. F. Sternum, ventral view. Scale bars: A–B = 1 mm; C–D, F = 0.5 mm; E = 0,02 mm.

Fig. 9. SEM micrographs of Ammonius benoiti sp. nov. (RMCA 202354). A. Carapace, dorsal view. B. Eye tubercle, dorsal view. C. Tibia I, prolateral view. D. Detail of tibial thorns, retrolateral view. Abbreviations: ALE = anterior lateral eyes; PLE = posterior lateral eyes; PME = posterior median eyes. Scale bars: A = 0.5 mm; B–C = 0.3 mm; D = 0.1 mm.

Fig. 2. Male palp of Ammonius pupulus Thorell, 1899. A–D. Holotype, ♂ (NHRS-GULI37848). A. Dorsal view. B. Ventral view. C. Prolateral view. D. Retrolateral view. E–F. SEM micrographs of the male palp of Ammonius pupulus (RMCA 227221). E. Prolateral view. F. Retrolateral view. G. Drawing from Benoit (1965: fig. 1), ventral view. Abbreviation: Tc = Tibial concavity. Scale bars: A–D = 1 mm; E–F = 0.5 mm.

Fig. 3. SEM micrographs of the male palp of Ammonius pupulus Thorell, 1899 (RMCA 227221). A–B. Tibial concavity. A. Prolateral view. B. Retrolateral view. C–D. Cymbium. C. Prolateral view. D. Retrolateral view. Abbreviations: Em = embolus; PL = prolateral lobe; So = slit organ; Tc = tibial concavity. Scale bars: A = 400 µm; B = 200 µm; C–D = 400 µm.

Fig. 8. Ammonius benoiti sp. nov. A–E. Holotype, ♂ (RMCA 202482). A. Habitus dorsal. B. Habitus ventral. C–E. Male palp. C. Prolateral view. D. Ventral view. E. Retrolateral view. F–J. Paratype, ♂ (RMCA 202354), male palpal bulb. F. Ventral view. G. Dorsal view. H. Prolateral view. I. Retrolateral view. J. Tibia I, prolateral view. Abbreviations: Ms = Megaspine; Tt = Tibial thorns. Scale bars: A–E, J = 0.5 mm; F–I = 0.2 mm.

Fig. 6. SEM micrographs of Ammonius pupulus Thorell, 1899, ♂ (RMCA 169417), tarsus I. A. Lateral view. B. Detail of frictional setae, lateral view. C–D. Detail of the chemosensory setae. Abbreviations: Ch = chemosensory setae; ChM = chemosensory setae male; CT = claw tufts; FS = frictional setae; STC = superior tarsal claws. Scale bars: A = 100 µm; B–C = 50 µm; D = 30 µm.

Fig. 7. SEM micrographs of Ammonius pupulus Thorell, 1899, ♀ (RMCA 169416), tarsus IV. A. Lateral view. B. Detail of macrosetae, lateral view.C. Chemosensory setae.D. Apical detail of the chemosensory setae. E. Scale setae. F. Chemosensory setae. Abbreviations: Ch = chemosensory setae; CT = claw tufts; FS = frictional setae; STC = superior tarsal claws. Scale bars: A = 100 µm; B–C = 50 µm; D = 20 µm; E = 50 µm; F = 30 µm.