Phylogeny of the Neotropical Hypoctonine Whip-Scorpions (Thelyphonida, Thelyphonidae), with Descriptions of Two New Genera and Species.

Thelyphonida Blanchard, 1852, also known as vinegaroons or whip-scorpions, is a small arachnid order with 140 described species contained in a single family, Thelyphonidae Lucas, 1835. Despite being conspicuous and widely distributed across the tropics and subtropics on four continents, knowledge of the order has been slow to advance. Hypoctoninae Pocock, 1899, one of four subfamilies currently recognized and one of two represented in the New World, comprises five genera.

On the sun-spiders of the ibirapemussu species-group of the genus Gaucha Mello-Leitão, 1924 (Solifugae, Mummuciidae), with description of a new species.

A new solifuge species in the genus Gaucha Mello-Leitão, 1924 and the ibirapemussu species-group is herein described based on males and females collected at Itacuruba, State of Pernambuco, and Jaicós, State of Piauí, both in Northeastern Brazil. Males of the new species can be readily recognized by having the movable finger MM and MSM teeth reduced and of similar size. The present finding raises to twelve the number of described species in the genus, five of which belong to the ibirapemussu species-group.

Two new species of the sun-spider genus Gaucha from Argentina and Brazil (Solifugae, Mummuciidae).

Two new species in the South American sun-spider family Mummuciidae are herein described. Gaucha ramirezi sp. nov.

A new species in the troglomorphic scorpion genus from Colombia, representing the northernmost known record for the genus (Scorpiones, Troglotayosicidae).

We describe a new scorpion species in the troglomorphic genus Troglotayosicus Lourenço, 1981 from Colombia. Troglotayosicus meijdeni sp. nov.

A remarkable new species of the magnus species-group of Cryptocellus (Arachnida, Ricinulei) from Ecuador, with observations on the taxonomy of the New World genera.

A new ricinuleid species, Cryptocellus chimaera sp. nov., is described based on a male specimen from Northwest Ecuador (Esmeraldas, Reserva Ecológica Mache-Chindul, Estación Biológica Bilsa).

Chileotrecha romero (Kraus, 1966) comb. nov. and Pseudocleobis patagonicus (Roewer, 1934) comb. nov. transferral from Mummuciidae to Ammotrechidae (Arachnida, Solifugae).

The solifuge species Mummucina romero Kraus, 1966, from Chile, and Mummucia patagonica Roewer, 1934, from Argentina, are here transferred from Mummuciidae Roewer, 1934 to Ammotrechidae Roewer, 1934. Chileotrecha romero (Kraus, 1966) comb. nov.

Scorpion sheds 'tail' to escape: consequences and implications of autotomy in scorpions (Buthidae: Ananteris).

Autotomy, the voluntary shedding or detachment of a body part at a determined cleavage plane, is a common anti-predation defense mechanism in several animal taxa, including arthropods. Among arachnids, autotomy has been observed in harvestmen, mites, and spiders, always involving the loss of legs. Autotomy of the opisthosoma (abdomen) was recently reported in a single species of the Neotropical buthid scorpion genus Ananteris Thorell, 1891, but few details were revealed.

Redescription of the sun-spider Mummucina titschacki Roewer, 1934 (Solifugae, Mummuciidae) with notes on the taxonomy of the genus.

Mummucina Roewer, 1934 is the second largest genus in the South American sun-spider family Mummuciidae. The limits of this and other genera are largely unexplored, and the traditional classification system is controversial. In the present contribution, the type species Mummucina titschacki Roewer, 1934 is redescribed, aided by scanning electron micrographs and the examination of a series of 72 specimens (including males) from the type locality in Ecuador.

A new Colombian species of Cryptocellus (Arachnida, Ricinulei), with notes on the taxonomy of the genus.

Cryptocellus sofiae sp. nov. is described based on males and females obtained from the easternmost part of Colombia, in Vichada Department.

A new species of Tityus (Scorpiones, Buthidae) from El Edén Cave, Colombia.

A new scorpion species, Tityus (Tityus) grottoedensis sp. nov., is herein described based on male and female specimens collected in El Edén Cave and its vicinities (Tolima department, Colombia).

Two new species of Ananteris (Scorpiones, Buthidae) from El Tuparro Natural National Park, eastern Colombia.

Two new scorpion species, Ananteris faguasi sp. nov. and Ananteris volschenki sp.