| Troglosiro aelleni |
|1 genus, 13 species|
Troglosironidae is a family of harvestmen with thirteen described species in a single genus, Troglosiro, which is found on the island of New Caledonia, in the Pacific Ocean.
The name of the genus giving the family its name is a combination of Ancient Greek troglos "cave", and the harvestman genus Siro, a reference to the habitat of the type specimen. Despite this, the genus does not appear to be adapted for a troglobitic lifestyle, and subsequent specimens have been collected from Berlesate (soil samples run through a Berlese Funnel).
Troglosironidae are 1.7 to 2.5 mm long and eyeless. They have mostly smooth, robust chelicerae, with or without a dorsal crest on the basal segment. They have laterally projecting ozophores, tarsal claws on the second pair of legs with a row of teeth, no opisthosomal median furrow, and a lamelliform adenostyle. The coxae 2 are not fused to the coxae 3, but sternites 8 and 9, and tergite 9, are all fused together, forming a complete corona analis. Exocrine gland pores are located on the sternum. These gland pores form unique depressions in most species, except for those found on the northern half of the island. The spermatopositor of the males also exhibit a unique setation pattern, as well as enlarged moveable fingers with toothed margins.
Troglosironidae is found exclusively on the island of New Caledonia, although the possibility exists that they could inhabit nearby islands as well.They can be found in leaf litter across the island, in both low and high elevations.
The family is believed to be an ancient relict of a once-widespread group that managed to survive on the island, as opposed to a more recent group that dispersed across the ocean, as the dispersal ability of Cyphophthalmi in general is regarded as poor.
Species in the north of the island and the south of the island form 2 distinct lineages, indicated by morphological differences in the sternum of species collected from the 2 different regions.
Troglosironidae was erected as a family in 1993, upon the discovery of 5 additional species of the formerly monospecific Troglosiro. The family was originally placed alongside Petallidae and Sironidae in the infraorder Temperophthalmi, but later analyses recovered Troglosironidae in a close relationship with Neogoveidaeand Ogoveidae, and was moved to the newly erected infraorder Sternophthalmi as the sister family to the superfamily Ogoveoidea, which contains the 2 latter families.
A cladistic analysis was conducted for the internal relationships of the family in 2009, the results of which are reproduced here. The species Troglosiro platnicki and T. tillierorum (marked with *) were not used in the study, and their position in the phylogeny is speculative, though probable based on morphological similarities.However, it has been suggested that T. platnicki may be synonymous with T. juberthiei. This study also recovered the divergence between the two lineages of Sternophthalmi (Ogoveoidea and Troglosironidae) to have occurred approximately 221 million years ago, and the family Troglosironidae to have emerged approximately 49 million years ago. Another study recovered older ages, with the divergence of the Sternophthalmi lineages to have occurred approximately 279 million years ago, with the emergence of Troglosironidae to have occurred approximately 57 million years ago. This family is thought to be the youngest Cyphophthalmi family by a wide margin, although no data exists regarding the age of Ogoveidae.
|Recovered by Sharma & Giribet (2009)|
There are currently 13 described species of Troglosiro,listed below, and one undescribed species, which was discovered in 2009.
The Opiliones are an order of arachnids colloquially known as harvestmen, harvesters, or daddy longlegs. As of April 2017, over 6,650 species of harvestmen have been discovered worldwide, although the total number of extant species may exceed 10,000. The order Opiliones includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi, which were named in 2014.
Cyphophthalmi is a suborder of harvestmen, colloquially known as mite harvestmen. Cyphophthalmi comprises 36 genera, and more than two hundred described species. The six families are currently grouped into three infraorders: the Boreophthalmi, Scopulophthalmi, and Sternophthalmi.
Ogoveidae is a family of harvestmen with three described species in one genus, Ogovea, which is found in equatorial West Africa.
The Neogoveidae are a family of harvestmen with 27 described species in eight genera. However, eight species of Huitaca, 17 species of Metagovea and 12 species of Neogovea are currently awaiting description.
The Stylocellidae are a family of harvestmen with about 30 described species, all of which occur from India to New Guinea. Members of this family are from one to seven millimeters long. While Stylocellus species have eyes, these are absent in the other two genera.
The Pettalidae are a family of harvestmen with 75 described species in 10 genera. Several undescribed species are known or assumed in some genera.
Ischyropsalididae is a family of harvestmen with 31 described species in 3 genera, found in Europe and North America.
Harvestmen (Opiliones) are an order of arachnids often confused with spiders, though the two orders are not closely related. Research on harvestman phylogeny is in a state of flux. While some families are clearly monophyletic, that is share a common ancestor, others are not, and the relationships between families are often not well understood.
Theromaster brunneus is a species of armoured harvestman in the family Travuniidae. It is found in North America.
Travunioidea is a superfamily of armoured harvestmen in the order Opiliones. There are 4 families and more than 70 described species in Travunioidea.
Vonones is a genus of armoured harvestmen in the family Cosmetidae. There are at least two described species in Vonones.
Paranonychus is a genus of harvestman in the family Paranonychidae. There are at least three described species in Paranonychus.
Megacina is a genus of armoured harvestmen in the family Phalangodidae. There are at least four described species in Megacina.
Siro exilis is a species of mite harvestman in the family Sironidae. It is found in North America.
Speleonychia is a genus of armoured harvestmen in the family Cladonychiidae. There is at least one described species in Speleonychia, S. sengeri. It is found in Washington state.
Cryptomastridae is a family of armoured harvestmen in the order Opiliones. There are two genera and four described species in Cryptomastridae, found in Oregon and Idaho.
Briggsus is a genus of armoured harvestmen in the family Cladonychiidae. There are about five described species in Briggsus, found in the coastal forests of Oregon and Washington.
Buemarinoa is a genus of armoured harvestmen in the family Cladonychiidae. There is one described species in Buemarinoa, B. patrizii, found in Sardinia, Italy.