Ancylometes – A key to identify adult specimens
males
Note: Males of A. japura, A. pantanal and A. riparius are still unknown
1	Smaller species of the genus: prosoma length <9 mm (specimens from Amazonia)		2
1*	Larger species: prosoma length > 9 mm		3
2	Palp: membranous lobe large and transverse, covering base of embolus; median apophysis short and broad at base; conductor short, broad and bulged		Ancylometes jau
2*	Palp: membranous lobe longitudinally directed towards the base of the slender median apophysis, conductor long and curved,		Ancylometes amazonicus
3	Palp: embolus broadened with bifid apex, not embedded in the short conductor; prosoma length about 9.5 mm		Ancylometes hewitsoni (Amazonia)
3*	Palp: embolus filiform with pointed apex		4
4	Prosoma 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 mm		Ancylometes terrenus (Amazonia)
4*	Prosoma with broad marginal white bands		5
5	Palp: 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 mm		Ancylometes bogotensis (northern South America)
5*	Palp: median apophysis without internal bulge		6
6	Palp: 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 mm		Ancylometes rufus (Amazonian and Mata Atlântica rainforests)
6*	Palp: median apophysis short, broad and straight; membranous lobe semicircular to rectangular; metatarsi I and II dorsally whitish		Ancylometes concolor (southern South America)
females
1	Epyginal 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/projection		2
2	Epigynal median plate widest in its posterior half, strongly enlarged, anterior border invaginated		Ancylometes amazonicus (Amazonia)
2*	Epigynal median plate widest anteriorly or medianly		3
3	Epigyne: lateral plates broader than median plate, median plate narrow trapezoidal, prominent, with narrow protuberance		Ancylometes hewitsoni (Amazonia)
3*	Epigyne: median plate at least as broad as the lateral plates		4
4	Epigynal 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 receptaculae		5
4*	Epigynal median plate widest anteriorly, forming a bike saddle; copulatory ducts more or less parallel		6
5	Epigynal median plate anteriorly with a spoon-like projection		Ancylometes pantanal
5*	Epigynal median plate anteriorly very broad, narrowing rapidly towards pointed posterior edge; a smaller species from Amazonia		Ancylometes jau
6	Copulatory ducts long and narrow		7
6*	Copulatory ducts broad and straight		8
7	Epigynal 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 edge		Ancylometes riparius (Amazonia)
8	Spermathecae more than one diameter apart; protuberance of epigynal median plate narrow		Ancylometes bogotensis (northern South America)
8*	Spermathecae less than one diameter apart		9
9	Epigynal 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, Amazonia		Ancylometes japura
9*	Epigynal median plate trapezoidal to drop-shaped, central protuberance narrow copulatory ducts broad, but not touching		Ancylometes concolor