Eight new species of Charinus Simon, 1892 are described for the Brazilian Amazon, from the states of Pará (C. bichuetteae sp. n., C. bonaldoi sp. n., C. carajas sp. n., C. ferreus sp. n., C. guto sp. n. and C. orientalis sp. n.) and Amazonas (Charinus brescoviti sp. n. and C. ricardoi sp. n.). All new species can be differentiated from the other species of the genus by the number of pseudo-articles in basitibia IV, the presence/absence of median eyes, and the shape of the female gonopod. Brazil now becomes the country with the largest diversity of Amblypygi in the world, with 25 known species. Half of the new species described here have a high degree of endangerment: C. bichuetteae sp. n. is threatened by the flood caused by the hydroelectric dam of Belo Monte, and C. carajas sp. n., C. ferreus sp. n. and C. orientalis sp. n. are endangered by the iron mining in Carajás municipality and surroundings. The Charinus species here described are endemic to the Amazon Region, so in order to assure their preservation, it is strongly recommended a special care with their habitats (type localities) which are facing increasing rates of destruction and deforestation.

The homology of three somatic systems in Schizomida is studied yielding the following results: (1) proposal of homology and chaetotaxy of abdominal setae in Surazomus; (2) revision of the cheliceral chaetotaxy in Schizomida, with suggestion of new homology scheme between Hubbardiidae and Protoschizomidae, description of a new group of setae in Hubbardiinae (G7), and division of setae group 5 in two subgroups, G5A and G5B; (3) proposal of segmental homology between trimerous and tetramerous female flagellum in Hubbardiinae with association of segment III of tri-segmented species to segments III + IV of tetra-segmented species. Considerations about the dorsal microsetae on the male flagellum are made. The genus Surazomus in Ecuador is revised. The sympatric species Surazomus palenque sp. nov. and S. kitu sp. nov. (Ecuador, Pichincha) are described and illustrated. The female of S. cuenca (Rowland and Reddell, 1979) is described, with two new distributional records for the species. Surazomus cumbalensis (Kraus, 1957) is recorded for the first time from Ecuador (Pichincha).

A new species of Charinus is described from Israel and new localities for C. ioanniticus are reported. Charinus israelensis sp. nov. is a cave dwelling species with extremely small median eyes, no median tubercle and reduced lateral eyes. It is similar to C. ioanniticus, which occurs in nearby areas, but can be differentiated by the shape of the carapace, the number of pedipalp spines and the development of the eyes. A detailed comparison is made between the two species, including pictures, drawings and scanning electron micrographs. Charinus ioanniticus is reported here from several new localities in Israel and Turkey. Identification keys to the Charinus species groups and to the species of the bengalensis group are provided.

A new species of the genus Sarax Simon, 1892 is described from Panay Island, Philippines. Sarax curioi sp. n. is the second species of the genus from the country and can be distinguished from the other Philippine species (Sarax brachydactylus Simon, 1892) by the sclerotized granules of the pedipalp surface, the spines of the pedipalp distitibia, the number of denticles of the chelicerae claw and the shape of the denticles of the chelicerae basal segment. Sarax newbritainensis Rahmadi and Kojima, 2010 is newly recorded from New Ireland Island, Papua New Guinea.

The present contribution addresses the phylogeny and biogeography of the pantropical whip spider family Charinidae Quintero, 1986, the most species-rich in the arachnid order Amblypygi Thorell, 1883, based on morphology and multilocus DNA sequences, analysed simultaneously using parsimony, maximum likelihood and Bayesian inference. The morphological matrix comprises 138 characters, scored for four outgroup taxa and 103 ingroup terminals representing all genera and 64% of the species of Charinidae. The multilocus dataset comprises sequences from two nuclear and three mitochondrial gene loci for four outgroup taxa and 48 ingroup representing 30 (23%) taxa of Charinidae. Charinidae are monophyletic, with Weygoldtia Miranda et al., 2018 sister to a monophyletic group comprising Charinus Simon, 1892 and Sarax Simon, 1892, neither of which are reciprocally monophyletic. Charinidae diverged from other amblypygid families in the Late Carboniferous, c. 318 Mya, on the supercontinent Pangaea. Weygoldtia diverged from the common ancestor of Charinus and Sarax during the Late Permian, c. 257 Mya, when changes in climate reduced tropical forests. The divergence of Charinus and Sarax coincides with the fragmentation of Pangaea, c. 216 Mya. Sarax colonized South-East Asia via Australia. The charinid fauna of New Caledonia originated before the Oligocene, when the island separated from Australia, c. 80 Mya.