The Ornithocheyletiini: Making a Living off Birds

In an earlier post, I commented on the carnivorous mites of the family Cheyletidae. These rapacious micropredators are commonly associated with the nests and burrows of terrestrial vertebrates, attacking debris-feeders drawn in by the host’s leavings. With such a close association already in place, it should come as little surprise that some lineages within the… Continue reading The Ornithocheyletiini: Making a Living off Birds

Pseudogagrella: A Harvestman Torn

The Sclerosomatidae are one of the most diverse of the currently recognised harvestmen families, and one of the most problematic when it comes to classification. In various earlier posts, I have noted the challenges that bedevil sclerosomatid systematics, many reflecting a historical focus on superficial external features of questionable evolutionary significance. Perhaps no taxon more… Continue reading Pseudogagrella: A Harvestman Torn


Reconstruction of Arthrolycosa fortis, from Fritsch (1904). Belongs within: Araneida. The Mesothelae are a group of spiders in which the abdomen retains external segmentation, the fangs are obliquely angled and the spinnerets are more or less displaced to the centre of the abdomen (Wunderlich 2019). Living members of the group are restricted to eastern Asia… Continue reading Mesothelae


Desert bush spider Diguetia canities, from the National Park Service.Belongs within: Araneida. Contains: Scytodoidea, Pholcidae, Segestriidae, Dysderidae, Orsolobidae, Oonopidae. The Basalhaplogynae are a clade of spiders in which the chelicerae are fused at the base and provided with a lamina; members of the clade also have the tegulum and subtegulum fused and the spinnerets lack… Continue reading Basalhaplogynae


Lampshade spider Hypochilus thorelli, copyright Marshal Hedin.Belongs within: Araneida. Contains: Argyronetidae, Hahniidae, Leptonetoidea, Plectana, Palpimanoidea, Eresoidea, Nicodamidae, Araneoidea, Austrochiloidea, Deinopoidea, Dictynidae, Amaurobioidea, Phyxelididae. The Neocribellatae are a clade of spiders in which a sieve-like spinning plate, the cribellum, evolved in front of the spinnerets, though this feature has been secondarily lost in many derived subgroups.… Continue reading Neocribellatae


Xysticus cristatus, copyright Philippe Garcelon.Belongs within: Thomisidae. Xysticus, ground crab spiders, is a genus of crab spiders with a generally flattened abdomen, carapace with the front distinctly higher than the back, and the two pairs of lateral eyes on incompletely joined tubercles. <==Xysticus |–X. altaicus Simon 1895 S95 |–X. audax R14 |–X. bifasciatus CM07 |–X.… Continue reading Xysticus


Female Thomisus onustus, copyright Lucarelli.Belongs within: Thomisidae. Thomisus is a genus of crab spiders, a number of species of which are brightly coloured to match flowers on which they wait to ambush visiting insects. <==Thomisus Walckenaer 1805 [Thomisinae] JD-S07 |–T. albens S95 |–T. albus K01 [incl. T. albidus S95] |–T. amboinensis Doleschall 1857 D57 |–T.… Continue reading Thomisus


Broad-faced sac spidersTrachelas tranquillus, copyright Judy Gallagher. Belongs within: Dionycha. Contains: Lamponidae, Liocranidae, Micaria, Gnaphosidae, Prodidomidae, Phrurolithidae, Gallieniellidae. The Gnaphosoidea are a clade of spiders that mostly have flat posterior median eyes whose tapeta have the middle dark lines orthogonal to each other, allowing the tapeta to function as a polarised light compass (Ramírez 2014).… Continue reading Gnaphosoidea


Nomaua repanga, copyright Te Papa Tongarewa. Belongs within: Araneoidea. The Synotaxidae are a group of small spiders found in Australasia and South America. They construct webs that vary from irregular sheets to an inverted bowl or lattice-like structure (Jocqué & Dippenaar-Schoeman 2007). Characters (from Jocqué & Dippenaar-Schoeman 2007): Very small to small; three tarsal claws;… Continue reading Synotaxidae