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Family Triaenonychidae – version 1.0

Adriano B. Kury

Departamento de Invertebrados, Museu Nacional/UFRJ

Quinta da Boa Vista, São Cristóvão, 20.940-040, Rio de Janeiro - RJ – BRAZIL

1. Introduction

The Triaenonychidae is a large family of a little less than 500 described species of

small to medium-sized Laniatores distributed in the Northern and Southern Temperate

Regions of the World. Recognizable by the posterior claws which are single with one or

more pairs of lateral branches, exceptionally with more complex ramifications. Genitalia is

complex, with many sclerites, all external. Definition of the family uses only

symplesiomorphies, so it is not a surprise not to recover a monophyletic Triaenonychidae

from phylogenetic analyses. They are the dominant element of the opiliofauna in

Madagascar, South Africa and New Zealand. In Chile they share the importance with the

Gonyleptidae. The biggest Triaenonychidae occur in Madagascar (Triaenonychinae) and

South Africa (Adaeinae). There is a lot of undescribed genera and species in Chile, and

many generic reviews are due, since different authors working with fauna of different

continents did not establish a standard for descriptions and diagnostic characters.

Intercontinental relationships are very interesting and little studied, telling part of the story

of Temperate Gondwana (Kury 2004).

1.1. Subtaxa included.

The 121 genera and 478 species are organized in up to 6 subfamilies, although

there is no consensus among the authors. Five subfamilies are small while the nominal

subfamily concentrates most of diversity of the family (108 genera and 435 species) and is

divided in three tribes. Four of the subfamilies are actually closest to the Travuniidae and

Pentanychidae (Kury, 2004) and should not properly be included here, while the New

Zealand Synthetonychiidae should be grouped inside Triaenonychidae. Two alternative

classifications are shown below.

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Compromise Conservative Classification Bold Alternative Classification

Triaenonychidae Sørensen, 1886

Kaolinonychinae Suzuki, 1976

Nippononychinae Suzuki, 1976

Paranonychinae Briggs, 1971

Sclerobuninae Dumitrescu, 1976

Soerensenellinae Forster, 1954

Triaenonychinae Sørensen, 1886

Adaeini Pocock, 1902

Triaenobunini Pocock, 1902

Triaenonychini Sørensen, 1886

Triaenonychidae Sørensen, 1886

Adaeinae Pocock, 1902

Synthetonychiinae Forster, 1954

Soerensenellinae Forster, 1954

Triaenonychinae Sørensen, 1886

Triaenobuninae Pocock, 1902

(None of the others belongs to this family)

1.2. Systematic historical background

Before the family was recognized, only a few species were described – Packard

(1877) described Scotolemon robustus from Colorado, USA, while Simon (1880) described

the genus Equitius for Equitius doriae from Australia. Karsch (1880) described the genus

Adaeum for Adaeum asperatum from South Africa considering it to be an intermediate

between the families Cosmetidae and Gonyleptidae (!). Sørensen (1886) created the family

“Triaenonychoidae”, with two more genera and two species – genus Triaenonyx for

Triaenonyx rapax Sørensen, 1886 from “Polynesia”, but actually from Chile and genus

Triaenobunus for Triaenobunus bicarinatus Sørensen, 1886. Slowly other species started to

be discovered. Banks (1893) described the genus Sclerobunus for Packard’s species and a

new one from Western USA and Loman (1898) the genera Acumontia for Acumontia

armata from Madagascar, Larifuga from South Africa and two more species of Adaeum.

20th century brought the first great change, when Pocock (1902) split the young

family in three different ones – Adaeidae, Triaenobunidae and Triaenonychidae. At the

same time Sørensen (1902) was describing more Chilean species, Pocock added some

species from South Africa, Madagascar and Australia/New Zealand (1902; 1903) and

Loman (1902) from New Zealand. Loman created without much explanation the new

suborder Insidiatores for Triaenonychidae (only later including the subdivisions by Pocock),

and in view of the heavy critics of Pocock, explained properly his views shortly later

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(Loman, 1903). Hogg (1910) described a few new Zealand species. Roewer (1915) did the

first monograph on the family, with an update 16 years later (Roewer 1931).

The excellent papers by Lawrence (e. g. 1931; 1938a; 1963) greatly enhanced the

knowledge on South African Fauna. Forster, in a review of Laniatores from New Zealand

(Forster 1954), described a lot of new species and genera and created a much influential

new system. Hickman (1958) created a great number of new genera and species for

Tasmania. Briggs (1967; 1971) reviewed most USA species and proposed a new subfamily.

Suzuki (1975; 1976) followed Briggs paradigm and proposed yet two new subfamilies of

Japanese/Korean Triaenonychidae. Dumitrescu (1976) based on studies of the midgut

diverticules proposed another subfamily, ignored by all other authors.

Maury (e. g. Maury & Roig, 1985) started a fine series of papers devoted to the

review of South American Triaenonychidae, containing high-quality illustrations of genitalia

and including a significant discussion on the systematics of the superfamily Travunioidea by

occasion of the description of a strange Argentinean troglomorphic species (Maury, 1988).

This series was interrupted by his untimely death. Hunt (e. g. Hunt, 1985; Hunt &

Hickman, 1993) reviewed some Australian taxa and made objections to current generic

cuts. Unfortunately this author also passed away prematurely.

1.3. Natural history

A review of cavernicolous members of the family is given by Hunt (1972). Lawrence

(1938b) studied devices of spreading repugnatory fluid. Austral Triaenonychidae are

typically found under rotten logs and in leaf litter. Some species possess a cover of earth

particles adhered to the complexly ornamented tegument. Forster (1954) separated a

whole subfamily, Soerensenellinae based on maternal care of the eggs, contrasting with

the other(s) in which such behavior was never observed: “Eggs laid in a single group under

a log or stone and guarded by female until hatched.” Some South African species possess

a stridulatory grate on the mesal surface of cheliceral hand, but actual stridulation has

never been reported.

2. Characterization

SIZE. Medium-sized Laniatores, body length typically 3 to 5 mm, although some

South African Triaenonychinae can be much smaller (down to 1.5 mm) and on the other

side some Adaeinae are much larger (up to 9 mm). Legs I-IV almost always short 4-7/6-

12/4-8/6-10 mm long. DORSUM. Dorsal scutum width increasing backwards without major

constriction. Mesotergum seldom clearly divided into areas by grooves, usually areas are

marked by arrangement of tubercle rows. No areas fused. Armature of areas and tergites

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usually weak, formed by small paired acuminate spiniform tubercles. Common eye mound

usually present, mostly very narrow and high with unpaired armature. Sometimes common

eye mound lacking and eyes are sessile placed close together. Eyes elevated, much higher

than the level of carapace. Anterior margin of carapace with rows of spines. Ozopores

hidden by a pad-shaped apophysis of coxa II. VENTER. Coxae more or less parallel, coxa IV

not greatly enlarged. Stigmata sometimes concealed by tubercles. Shape of sternum much

variable. CHELICERA. Cheliceral hands usually not swollen, and basichelicerite rarely with

dorsal ornamentation of tubercles, but mesal rows of pointed tubercles are common.

PEDIPALP. Pedipalps large, much stronger than legs, not crossed in the region of

trochanter. Armed with ventro-mesal and ventro-ectal spines in patella-tibia-tarsus. Femur

variedly armed with apophyses and spines, ventrally in many genera with strip of fine

bead-like granules. Tibia and tarsus do not form a subchela. LEGS. Legs usually short,

substraight and armed only with tubercle rows. Large elaborate apophyses never present.

Coxa I ventrally with strong frontal apophyses. Femur I in many species armed with

ventral and/or dorsal rows of setiferous spiniform processes. Metatarsus I may be notched

in males and provided with strong setae. Tarsi I-II with a single claw, III-IV with a

multifurcate (usually trifurcate) claw. Distitarsus I undivided or 2 jointed. Distitarsus II

typically 2 jointed, may reach 4 joints. Tarsal counts typically 2-3/2-8 (reaching more than

20)/3-4/3-4. COLOR. Color background usually orange-brown to dark-brown, with black

mottling and reticulation. No white markings on dorsal scutum. GENITALIA. Truncus penis

filled with a single muscle. Glans very complex, with a full complement of sclerites, rarely

found together in a same species. Sometimes stylus is extremely elongate and plates and

spines may be fused with it. MALE DIMORPHISM (POECILANDRY). Reported by Forster

(1954) and Hunt (1985), some males have secondary dimorphic features only weakly

developed, though genitalia are normal. SEXUAL DIMORPHISM. Sexual dimorphism is

manifested typically in pedipalps, which in male are much stronger and incrassate. In a few

species, chelicerae of male have supplementary spatulate mesal apophyses. The number of

tarsal counts of leg I in female may be a little lower. In many species males possess a

notch in metatarsus I.

3. Distribution

USA, Japan, Korea, Australia, New Zealand, Madagascar, Chile, Argentina and

southern Brazil. It is interesting to note that some genera of Triaenonychidae are

distributed across the Austral continents, not to mention the possibly non-Triaenonychidae

of the Boreal temperate that also cross continents (Paranonychinae, see Shear, 1986).

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4. Relationships

In the chapter of evolution in this book and elsewhere (Kury, 2004), reasons are

given to split the Triaenonychidae as traditionally conceived in at least two different

families. The Boreal genera should be grouped with the Travuniidae while the Austral

genera represent the Triaenonychidae sensu stricto and may include the strange

Synthetonychiidae.

5. References

Banks, Nathan, 1893. The Phalangida Mecostethi of the United States. Trans. American

Entomol. Soc., 20(2): 149-152.

Briggs, Thomas S., 1967. An emendation for Zuma acuta Goodnight & Goodnight

(Opiliones). Pan-Pacific Entomologist, 43: 89.

Briggs, Thomas S., 1971. The harvestmen of family Triaenonychidae in North America

(Opiliones). Occ. Pap. Calif. Acad. Sci., 90: 1-43.

Dumitrescu, Dan, 1976. Recherches morphologiques sur l’appareil digestif (intestin moyen)

des Gonyleptomorphi (Arachnida, Opilionida). Trav. Mus. Hist. Nat. “Gr. Antipa”, 17: 17-

30.

Forster, Raymond R. 1954. The New Zealand harvestmen (sub-order Laniatores).

Canterbury Museum bulletin, Christchurch, 2: 1-329.

Hickman, V. V. 1958. Some Tasmanian harvestmen of the family Triaenonychidae (sub-

order Laniatores). Papers and proceedings of the Royal Society of Tasmania, Hobart

Town, 92: 1-116.

Hogg, Henry R. 1910. Some New Zealand and Tasmanian Arachnidae. Transactions of the

New Zealand Institute, Wellington, 42(33): 273-283.

Hunt, Glenn S. 1972. A new cavernicolous harvestman from Western Australia (Arachnida:

Opiliones: Triaenonychidae). Journal of the Australian Entomological Society, Brisbane,

11(3): 232-236.

Hunt, Glenn S. 1985. Taxonomy and distribution of Equitius in Eastern Australia (Opiliones,

Laniatores, Triaenonychidae). Records of the Australian Museum, Sydney, 36: 107-125.

Hunt, Glenn S., 1992. Revision of the genus Holonuncia Forster (Arachnida: Opiliones:

Triaenonychidae) with description of cavernicolous and epigean species from Eastern

Australia. Records of the Australian Museum, Sydney, 44: 135-163.

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Hunt, Glenn S. & John L. Hickman. 1993. A revision of the genus Lomanella Pocock and its

implications for family level classification in the Travunioidea (Arachnida: Opiliones:

Triaenonychidae). Records of the Australian Museum, Sydney, 45: 81-119.

Karsch, Ferdinand. 1880. IX. Neue Phalangiden des Berliner Museums, pp 400-404. In

Arachnologische Blätter (Decas I). Tafel 12. Zeistschrift fur die gesamten

Naturwissenschaften, Berlin, 53(6): 373-409.

Kury, Adriano B., 2004. Intercontinental relationships of Southern Hemisphere

Triaenonychidae. Cimbebasia, Windhoek [ in review].

Lawrence, Reginald F. 1931. The harvest-spiders (Opiliones) of South Africa. Annals of the

South African Museum, Cape Town, 29: 341-508.

Lawrence, R. F., 1937. New harvest-spiders from Natal and Zululand. Annals of the Natal

Museum, Pietermaritzburg, 8(2): 127-153, 11 fig.

Lawrence, Reginald F. 1938a. Harvest-spiders of Natal and Zululand. Annals of the Natal

Museum, Pietermaritzburg, 8(3): 345-370.

Lawrence, Reginald F. 1938b. The odoriferous glands of some south african harvest-

spiders. Transactions of the Royal Society of South Africa, Cape Town, 25(4): 333-342.

Lawrence, Reginald F. 1963. The Opiliones of the Transvaal. Annals of the Transvaal

Museum, Pretoria, 24: 275-304.

Loman, Jan Cornelis Christiaan. 1898. Beiträge zur Kenntniss der Fauna von Süd-Afrika.

Ergebnisse einer Reise von Prof. Max Weber im Jahre 1894. IV. Neue Opilioniden von

Süd-Afrika und Madagaskar. Zoologische Jahrbücher, Jena, Abteilung für Systematik,

Geographie und Biologie der Tiere, 11: 515-530.

Loman, Jan Cornelis Christiaan. 1902. Neue aussereuropaische Opilioniden. Zoologische

Jahrbücher, Jena, Abteilung für Systematik, Ökologie und Geographie der Tiere, 16:

163-216, pr. 9.

Loman, Jan Cornelis Christiaan. 1903. On the classification of Opiliones. Tijdschrift der

Nederlandsche dierkundige vereeniging, Rotterdam, 8: 62-66.

Maury, Emilio A., 1988. Triaenonychidae sudamericanos V. Un nuevo genero de opiliones

cavernicolas de la Patagonia (Opiliones, Laniatores. Mémoires de Biospéologie, 15: 117-

131.

Maury, Emilio A., 1993. Triaenonychidae sudamericanos. VII. Redescripcion de

Araucanobunus juberthiei Muñoz Cuevas 1973 (Opiliones, Laniatores). Boletin sociedad

biologica Concepción, 64: 105-111.

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Maury, Emilio A. & Arturo H. Roig A., 1985. Triaenonychidae sudamericanos I. El género

Ceratomontia Roewer, 1915 (Opiliones: Laniatores). Historia Natural, 5(11): 77-92.

Packard Jr., Alpheus S., 1877. On a new cave fauna in Utah. Bull. U.S.A. Geol. Geogr.

Surv. Terr., 3(1): 157-169.

Pocock, Reginald Innes. 1902a. Some points in the morphology and classification of the

Opiliones. Annals and Magazine of Natural History: Zoology, Botany and Geology,

London, 7th Series, 10: 504-516.

Pocock, Reginald Innes. 1902b, On some new harvest-spiders of the order Opiliones from

the Southern Continents. Proceedings of the Zoological Society of London, London, 2

(6): 392-413.

Pocock, Reginald Innes. 1903a. Fifteen new species and two new genera of tropical

southern Opiliones. Annals and Magazine of Natural History: Zoology, Botany and

Geology, London, 7th Series, 11: 433-450, 2 pl.

Roewer, Carl-Friedrich. 1915a. Die Familie Triaenonychidae der Opiliones-Laniatores.

Archiv für Naturgeschichte, Berlin, Abt. A, Original-Arbeiten, 80(12): 61-168.

Roewer, Carl-Friedrich. 1931b. Über Triaenonychiden (6. Ergänzung der Weberknechte der

Erde 1923). Zeitschrift für wissenschaftliche Zoologie, Leipzig, 138(1): 137-185.

Shear, William A., 1986. A cladistic analysis of the opilionid superfamily Ischyropsalidoidea,

with descriptions of the new family Ceratolasmatidae, the new genus Acuclavella, and

four new species. American Museum Novitates, New York City, 2844: 1-29.

Simon, Eugène. 1880a. Premier supplément au travail intitulé essai d’une classification des

Opiliones Mecostethi, etc (première Partie). Comptes rendus des séances de la Société

Entomologique de Belgique, Bruxelles, 1880: 100-103.

Sørensen, William E. 1886a. Opiliones. In Ludwig Koch & E. von Keyserling, Die

Arachniden Australiens nach der Natur beschrieben und abgebildet, 2(33): 53-86, pl. 5-

6. Nürnberg: Bauer & Raspe.

Sørensen, William E. 1902. Gonyleptiden (Opiliones Laniatores). Ergebnisse der Hamburger

Magalhaensischen Sammelreise, 5: 1-36.

Suzuki, Seisho. 1975. The harvestmen of family Triaenonychidae in Japan and Korea.

Journal of Sciences of the Hiroshima University, series B1 (Zoology), 26: 65-101.

Suzuki, Seisho. 1976c. Two triaenonychid harvestmen from the Northeast Japan. Journal of

Sciences of the Hiroshima University, series B1 (Zoology), 26: 177-185.

Triaenonychidae. Figs 1-9. 1. Holonuncia katoomba Hunt, 1992 from Australia, habitus, lateral view (from Hunt, 1992); 2-3. South African Adaeinae, schematic granulation of Adaeulum (left) and Larifuga (from Lawrence, 1933); 4-5. Araucanobunus juberthiei Muñoz-Cuevas, 1973 from Chile, coxae, sternum and genital opercle of male and female (from Maury, 1993); 6. Typification of outlines of sternum of the three tribes of Triaenonychinae, from left, Triaenonychini, Adaeini, Triaenobunini (redrawn from Forster, 1954); 7. Further elaboration on the sternum outline of genera of South African Adaeini, from left, Montadaeum, Larifuga, Paradaeum, Adaeulum, Cryptadaeum (redrawn from Lawrence, 1931); 8-9. Gen. sp. of Triaenobuninae from Chile showing complex ornamentation (photos A.B.Kury).

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Triaenonychidae. Figs 10-20. 10. Araucanobunus juberthiei Muñoz-Cuevas, 1973 from Chile, penis ventral and lateral views (from Maury, 1993); 11. Ceratomontia mendocina Maury & Roig, 1985, from Argentina, penis lateral and ventral (from Maury & Roig, 1985); 12-14. Graemontia natalensis Lawrence, 1937 from South Africa chelicera mesal view, pedipalpus mesal view and leg I, mesal view (from Lawrence, 1937); 15. Ankaratrix illota Lawrence, 1959 from Madagascar, eye mound, lateral view (from Lawrence, 1959); 16. Pristobunus henopoeus Forster, 1954 from New Zealand, habitus, dorsal view (from Forster, 1954); 17. Gen. sp. from Madagascar (USNM) ozopore and pad of coxa II (photo A.B.Kury); 18. Holonuncia cavernicola Forster, 1955 from Australia, metatarsal notch (from Hunt, 1992); 19. Lomanella spp. posterior claws (from Hunt & Hickman, 1993); 20. Gen. sp. from Madagascar (USNM) typical 3-pronged claw . (photo A.B.Kury)

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