A harvestman (Arachnida: Opiliones) is described from the Early Devonian (Pragian) Rhynie cherts, Aberdeenshire, Scotland. Eophalangium sheari gen. et sp. nov. is the oldest known harvestman. The material includes both males and a female preserving, respectively, a cuticle-lined penis and ovipositor within the opisthosoma. Both these structures are of essentially modern appearance. The Rhynie fossils also show tracheae which are, again, very similar to those of living harvestmen. This is the oldest unequivocal record of arachnid tracheal respiration and indicates that E. sheari was terrestrial. An annulate, setose ovipositor in the female suggests that it can be excluded from the clades Dyspnoi and Laniatores, in which the ovipositor lacks such annulations. However, the penis shows evidence of two muscles, a feature of uncertain polarity seen in modern Troguloidea (Dyspnoi). The presence of median eyes and long legs excludes Cyphophthalmi, and thus, E. sheari is tentatively referred to the suborder Eupnoi. Therefore, this remarkable material is implicitly a crown-group harvestman and is one of the oldest known crown-group chelicerates. It also suggests an extraordinary degree of morphological stasis within the eupnoid line, with the Devonian forms differing little in gross morphology – and perhaps in reproductive behaviour – from their modern counterp

The paper reports on a new family of spiders from the eastern Cape region in South Africa. Chummidae, new family, are small, three-clawed spiders, recognized by the abdomen with strong dorsal scutum, provided with a frontal field of stiff macrosetae in large sockets. Further apomorphies are the absence of a fovea, the reduction of posterior and median spinnerets, the absence of major ampullate gland spigots, and the presence of branched lateral tracheae and of a hair-basket around the cheliceral fang. The type genus Chumma, is represented by two species, both known from male and female – the type species C. inquieta sp. nov. and C. gastroperforata sp. nov. The males of the latter species are remarkable for having two pairs of abdominal pockets, which play a role during mating.

Spiracle and tracheal structure in the extant Ixodida is revised and shown to comprise 29 distinct component characters, some of which are common to all Anactinotrichida, while others are unique to the Ixodida or one of its six component clades of ((Argasidae Nuttalliellidae) (Prostriata Metastriata)). Structural variation both between and within families is based upon combinations of minor differences in the component characters, only one of which, spiracular position, proved to be incongruent within the most parsimonious cluster- and tree-analysis solutions. Tracheal airflow in ticks is mediated via passive diffusion gradients. In the argasid spiracle, both aeropyles and ostium are functional, although the latter is only opened briefly during infrequent periods of activity. The ixodid ostium is sealed and all gas exchange takes place via an enlarged sieveplate which reduces transpiration via small aeropyles, an underlying dense array of pedicels and possibly hygroscopic sub-atrial glands. Changes in spiracular morphology from a more ‘ancestral’ argasid type to a more ‘derived’ ixodid type are correlated with changes in tick behaviour, particularly with increased activity associated with the change from nidicoly to host-seeking.