| Pettalidae | |
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| Adult Pettalus. Scale bar: 1 mm | |
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| Family: | Pettalidae Simon, 1879 |
| Diversity | |
| 10 genera, 75 species | |
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The Pettalidae are a family of harvestmen with 75 described species in 10 genera. [1] Several undescribed species are known or assumed in some genera. [2]
Pettalus is a name from Greek mythology that appears in Ovid's Metamorphoses. [2]
All species except the cave-dwelling South African Speleosiro argasiformis spend their entire life cycle in leaf litter.
They are two to five millimeters long, usually with an oval shaped body.
Although all Pettalidae except Parapurcellia have eyes, these were long thought to be absent in the family, mainly because they cannot be seen by scanning electron microscopy. They are often incorporated at the base of the ozophores and typically lack lenses. [1]
The members of this family are distributed throughout former temperate Gondwana, with genera in Chile, South Africa, Madagascar, Sri Lanka, eastern and western Australia, and New Zealand, where they are most diverse by far, with 29 species and subspecies found in three genera. [2]
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| Phylogeny of most Pettalidae(after Boyer & Giribet 2007) |
The family Pettalidae is monophyletic, although it is at the moment (2007) unclear what the nearest relatives are. It probably originated in the southern part of Gondwana. [1] Parsimony analysis suggests it could be a sister group to the remaining Cyphophthalmi, though this could also be the case for the Stylocellidae, [1] or it could be related to the Sironidae, or specifically to the sironid genus Suzukielus . [2] It is unrelated to the Troglosironidae that are endemic to New Caledonia.
The main lineages of the family may have arisen rapidly, possibly during the rapid expansion of Glossopteris forests that were predominant in temperate Gondwana. Pettalidae were likely present throughout the forests of Antarctica, which formed a land bridge between Australia and South America up until circa 50 million years ago (mya).
The Australian genera Austropurcellia (Eastern Australia: Queensland) and Karripurcellia (Western Australia) are not sister groups. It is possible that the Cyphophthalmi dispersed across Australia while the central region was covered with Nothofagus rainforest (until 37 mya), or that the ancestors of the two genera independently dispersed from adjacent landmasses now separate from Australia. [1]
Parapurcellia from eastern South Africa is sister to all other Pettalidae, while Purcellia from western South Africa is sister to the Chilean Chileogovea. Western South Africa and southern South America were last connected during the Late Jurassic, about 150 mya. Likewise, the monotypic Neopurcellia from New Zealand appears as the sister group to all Pettalidae except for Parapurcellia, instead of being monophyletic with the other two New Zealand genera, which themselves appear as sister groups in Bayesian analysis, but not in direct optimization parsimony analyses. [1]
The family Pettalidae contains the following genera and species: [3] [4]
Anapidae is a family of rather small spiders with 232 described species in 58 genera. It includes the former family Micropholcommatidae as the subfamily Micropholcommatinae, and the former family Holarchaeidae. Most species are less than 2 millimetres (0.079 in) long.
Cosmetidae is a family of harvestmen in the suborder Laniatores. With over 700 species, it is one of the largest families in Opiliones. They are endemic of the New World with a Nearctic-Neotropical distribution where a large fraction of the diversity of Opiliones are represented by this single family. Cosmetidae have the northern extent of their range into the USA, where a small number species occur in the southern states. However, the family is especially diverse in Mexico, Central America and northern South America; especially the Andean realms. Their range also extends further south into Argentina and southern Brazil, but they are absent in Chile. Cosmetidae are prevalent in Amazonian region, but only relatively few also occur in Brazilian Atlantic Forest. Several species are also found in the Caribbean.
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.
The Phalangodidae are a family of harvestmen with about 30 genera and more than 100 described species, distributed in the Holarctic region.
The Triaenonychidae are a family of harvestmen with about 120 genera and more than 440 described species.
The Neopilionidae are a family of harvestmen.
The Sironidae are a family of harvestmen with more than 30 described species.
Caddoidea superfamily of harvestmen arachnids with a single family Caddidae, which now only contains 2 extant species. The family previously contained many more taxa under a previous wider concept, but the familial definition was narrowed after restudy.
Troglosironidae is a family of harvestmen with seventeen described species in a single genus, Troglosiro, which is found on the island of New Caledonia, in the Pacific Ocean.
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 40 described species, all of which occur in Southern or Southeastern Asia. 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 Nemastomatidae are a family of harvestmen with about 170 described species in 16 recent genera. Several fossil species and genera are known.
Hedycarya is a genus of dioecious trees and shrubs of the family Monimiaceae. Species occur in South East Asia, New Caledonia, Australia and Polynesia including New Zealand. The genus was named and formerly described in 1776 by botanists Johann and Georg Forster in Characteres Generum Plantarum. The limit of the genus may require change as it appears paraphyletic in phylogenetic analyses, with the genera Kibaropsis and Levieria nested in it.
Acropsopilionidae is a family of harvestmen with 19 described species in 3 genera.
Algidia is a genus in the harvestman family Triaenonychidae. It is endemic to New Zealand and currently includes 12 species and subspecies.
Rakaia is a genus of harvestmen in the family Pettalidae with eighteen described species. All species are found in New Zealand.
