Ancylometes – A key to identify adult specimens


Note: Males of A. japura, A. pantanal and A. riparius are still unknown

1Smaller species of the genus: prosoma length <9 mm (specimens from Amazonia)2
1*Larger species: prosoma length > 9 mm3
2Palp: membranous lobe large and transverse, covering base of embolus; median apophysis short and broad at base; conductor short, broad and bulgedAncylometes jau
2*Palp: membranous lobe longitudinally directed towards the base of the slender median apophysis, conductor long and curvedAncylometes amazonicus
3Palp: embolus broadened with bifid apex, not embedded in the short conductor; prosoma length about 9.5 mmAncylometes hewitsoni
3*Palp: embolus filiform with pointed apex4
4Prosoma dorsally purpurish without white marginal bands; venter of abdomen with bright red triangle; distal segments (patellae, tibiae, metatarsi, tarsi) of legs covered by white hairs; palp: membranous lobe transverse and very broad, occupying whole basal part of the bulbus; prosoma length 11.5 - 14 mmAncylometes terrenus
4*Prosoma with broad marginal white bands5
5Palp: membranous lobe covering base of embolus; median apophysis with characteristic internal bulge; embolus with a small knob pointing to the membranous lobe; prosoma length 8.5-14 mmAncylometes bogotensis
(northern South America)
5*Palp: median apophysis without internal bulge6
6Palp: median apophysis long and slightly curved, membranous lobe triangular; largest species with prosoma length in Amazonian specimens 11-18 mm, in specimens from the Atlantic rainforest population 10-11 mmAncylometes rufus
(Amazonian and Mata Atlântica rainforests)
6*Palp: median apophysis short, broad and straight; membranous lobe semicircular to rectangular; metatarsi I and II dorsally whitishAncylometes concolor
(southern South America)


1Epyginal median plate without any projection; large spiders: prosoma length 12-18 mm Ancylometes rufus (Amazonian and Mata Atlântica rainforests)
1*Epigynal median plate with protuberance/projection2
2Epigynal median plate widest in its posterior half, strongly enlarged, anterior border invaginatedAncylometes amazonicus (Amazonia)
2*Epigynal median plate widest anteriorly or medianly3
3Epigyne: lateral plates broader than median plate, median plate narrow trapezoidal, prominent, with narrow protuberanceAncylometes hewitsoni
3*Epigyne: median plate at least as broad as the lateral plates4
4Epigynal median plate widest medianly, projecting above the lateral plates; internally the copulatory ducts describe a strong curve from the widely separated anterior openings to the close receptaculae5
4*Epigynal median plate widest anteriorly, forming a bike saddle; copulatory ducts more or less parallel6
5Epigynal median plate anteriorly with a spoon-like projectionAncylometes pantanal
5*Epigynal median plate anteriorly very broad, narrowing rapidly towards pointed posterior edge; a smaller species from AmazoniaAncylometes jau
6Copulatory ducts long and narrow7
6*Copulatory ducts broad and straight8
7Epigynal median plate drop-shaped, protuberance originating in the posterior part of the plate; copulatory ducts long and narrow; probably a species from non-inundated forests (terra firme)Ancylometes terrenus
7*Epigynal plate triangular, protuberance originating on the anterior edgeAncylometes riparius (Amazonia)
8Spermathecae more than one diameter apart; protuberance of epigynal median plate narrowAncylometes bogotensis (northern South America)
8*Spermathecae less than one diameter apart9
9Epigynal plate with large projection originating from the anterior border; copulatory ducts broad and touching medianly; the only known specimen very large: prosoma length 17 mm, from Japurá, AmazoniaAncylometes japura
9*Epigynal median plate trapezoidal to drop-shaped, central protuberance narrow copulatory ducts broad, but not touchingAncylometes concolor