A Cladistic Analysis of the Opilionid Superfamily

A Cladistic Analysis of the Opilionid Superfamily

AMERICAN MUSEUM Novitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2844, pp. 1-29, figs. 1-41, tables 1-9, maps 1-3 June 10, 1986 A Cladistic Analysis of the Opilionid Superfamily Ischyropsalidoidea, with Descriptions of the New Family Ceratolasmatidae, the New Genus Acuclavella, and Four New Species WILLIAM A. SHEAR' ABSTRACT A cladistic analysis ofthe opilionid superfamily lasmatidae is described as new for the genera Cer- Ischyropsalidoidea revealed three groups of gen- atolasma, Hesperonemastoma, Crosbycus, and era, each probably monophyletic, and recognized Acuclavella, new genus. Acuclavella consists offour here as families. The family Ischyropsalididae Si- new species from Idaho and Washington: cosme- mon is redefined to include only the genus Ischy- toides, shoshone, merickeli, and quattuor. Cros- ropsalis, the family Sabaconidae Dresco is ex- bycus dasycnemus (Crosby) is redescribed and il- panded to include Sabacon (=Tomicomerus, new lustrated, and new distribution records are given. synonymy) and Taracus, and the family Cerato- INTRODUCTION The opilionid family Ischyropsalididae has 1904), but nothing substantial was done re- been problematical for opilionologists for garding its composition or relationships until many years, with a piecemeal approach being Martens (1969) revised the type genus, dis- taken to the inclusion or exclusion ofvarious posing ofa vast plethora ofextraneous species taxa in the family. Originally proposed by names proposed by Roewer (1950). For the Simon (1879) to cover the genera Ischyrop- first time, Martens' work allowed some clear salis, Sabacon, and Taracus, the family was insights into the true nature ofthis taxon. For readily recognized (Hansen and Sorensen, example, he established that Ceratolasma tri- I Research Associate, Department of Entomology, American Museum of Natural History; Professor of Biology, Hampden-Sydney College, Hampden-Sydney, Virginia 23943. Copyright © American Museum of Natural History 1986 ISSN 0003-0082 / Price $3.20 2 AMERICAN MUSEUM NOVITATES NO. 2844 cantha, originally described by Goodnight and gestion of a family for Crosbycus alone, he Goodnight (1942) as a trogulid (on the mis- saw in the future. taken assumption it was related to Ortholas- Work with Sabacon, Crosbycus, Cerato- ma, now known to be a nemastomatid, but lasma, and Hesperonemastoma had suggest- at that time considered a trogulid also), was ed to me that there might be a solution to the in fact related at some level to Ischyropsalis, evident difficulties in the taxonomy of this while Taracus and Sabacon were more dis- family, and when evidence became available tantly so. A nonconforming element of the a few years ago ofan exciting new genus from family was removed when Martens and Su- Idaho and Washington related to Ceratolas- zuki (1966) showed that Nipponopsalis was ma, I resolved to try to make some sense of in fact allied in some way to the trogulids. relationships in the Ischyropsalidoidea. Later, Gruber (1978) and Shear and Gruber (1983) placed Ruaxphilos petrunkevitchou Goodnight and Goodnight (1945) in the syn- ACKNOWLEDGMENTS onymy of Ortholasma bolivari, an ortholas- I thank, first of all, Frank Merickel of the matine nemastomatid. University ofIdaho for his generosity in pro- Dresco (1970) suggested a monotypic fam- viding specimens ofAcuclavella and notes on ily for Sabacon, and this proposal was ac- their habits. He was referred to me by my cepted by Martens (1983), who characteris- colleague in American opilionid taxonomy, tically provided much better evidence for the James C. Cokendolpher (Texas Tech Uni- idea in his revision of European Sabacon. versity). I had first been made aware of the However, Martens did not include Taracus. existence ofthis new genus by Rod Crawford Gruber (1970) showed that the North ofthe Burke Memorial Museum, Seattle, who American species described by several au- sent a single female specimen from Lewis thors in Nemastoma were not even members County, Washington. The scanning electron of Nemastomatidae but related to Ischyrop- micrographs illustrating this paper were tak- salis; he gave them the new (unfortunate) en at the Virginia-Maryland College of Vet- name Hesperonemastoma. In several publi- erinary Medicine, through the kindness of cations, Gruber (1970) and Martens (1976, Brent Opell. Additional specimens of ischy- 1978) presented evidence for including Cros- bycus in the ischyropsalidid assemblage; ropsalidoids were provided by Cokendol- Martens persistently suggested a monotypic pher, by Jochen Martens (Johannes-Guten- new family for it, but has never actually used berg-Universitat, Mainz), and by Nobuo the name "Crosbycidae." Tsurusaki, Hokkaido University, Japan. Jiur- In two important papers, Martens (1976) gen Gruber (Natural History Museum, Vi- and Martens et al. (1981) used, among other enna [VM]) very kindly turned over to me characters, details of the penes and oviposi- his voluminous notes on Crosbycus dasy- tors to produce a widely accepted cladogram cnemus, and commented extensively on an ofthe order Opiliones. It was not unexpected earlier draft of this paper, as did Martens, that their analysis led to a dismemberment Cokendolpher, and Norman Platnick of the of the old "tribe" Dyspnoi, in which Ischy- American Museum of Natural History. Ma- ropsalididae had been allied with Nemasto- terial for study came from my own collection matidae, Dicranolasmatidae, Nipponopsali- and that ofthe American Museum ofNatural didae, and Trogulidae. Martens raised the History (AMNH; Norman Platnick), the Field taxon to superfamily level and placed it close Museum of Natural History (FMNH; Henry to the superfamilies Phalangioidea and Cad- Dybas and John Kethley), the Burke Me- doidea. morial Museum of the University of Wash- However, as Gruber (1978) had pointed ington (BMM; Rod Crawford), the Museum out, the single family Ischyropsalididae is one ofComparative Zoology at Harvard Univer- of the most heterogeneous taxa in Opiliones. sity (MCZ; H. W. Levi), and the personal He decried the solution of monotypic fami- collection of James C. Cokendolpher (JCC). lies for each genus, which, considering the This research was aided by grants from the Sabaconidae of Dresco, and Martens' sug- Faculty Research Fund of Hampden-Sydney 1986 SHEAR: ISCHYROPSALIDOIDEA 3 College, and by equipment purchased under and inserting by means of a long tendon on a grant (J-3 1) from the Jeffress Trust. the base of the glans. The penis, as in many other ischyropsalidoids, phalangioids, and nemastomatoids, bends at the base of the FAMILIES OF glans and the base of the stylus when this ISCHYROPSALIDOIDEA muscle contracts. According to Martens this The superfamily Ischyropsalidoidea has arrangement of the penial muscle and "wei- tere Merkmale, die hier nicht diskutiert wer- been defined by Martens (1976) and by Mar- den" justify a monotypic family for Sabacon. tens et al. (1981) on the basis of characters ofthe genitalia and palpi. The ovipositor has The additional characters are not given. As secondarily lost its segmentation (retaining Martens pointed out, at least one genus in vestiges ofsegmentation in the musculature), each of the families Phalangiidae and Nem- astomatidae have a very similar arrange- and the palpal claw is vestigial or absent. In ment, and just as importantly, there are at this study, I add to these characters the pres- least two other apomorphies (dense distri- ence of unique sensory cones on the meta- bution of plumose setae on the tibia and tar- peltidial midline. The superfamily corre- sponds roughly in extent to the old "family," sus of the palp, with the tarsus curved back on the of a slot in the the history of which was reviewed to 1976 tibia; presence deep by Gruber (1978). According to the analysis carapace between the chelicerae) shared by and Taracus, and Taracus does not of Martens, the sister group of Ischyropsali- Sabacon doidea is Caddoidea + Phalangioidea. Unit- have the penis muscle as in Sabacon. I there- of the in Sabacon ing these three taxa are two synapomorphies: fore regard the form penis as the one muscle in the penis and plumose setae an autapomorphy only for genus. shows that Sa- (figs. 2-9) on the palpi. This latter character, My cladistic analysis (fig. 1) and taken are the previously thought to occur primarily, if not bacon Taracus, together, exclusively, in the Ischyropsalidoidea, has sister group of all the other Ischyropsalidoi- basis I have decided to been verified for a number of species of Pha- dea. On this recognize a which includes these langioidea (Tsurusaki, personal commun.; family Sabaconidae, two genera. Cokendolpher, personal commun.; unpub- lished data) and Caddoidea (see fig. 5). How- Similarly, Ischyropsalis (with its isolated in central and western is ever, such setae may be synapomorphic for position Europe) shown to be the sister ofthe Opiliones as a whole, since scanning electron group remaining genera. I choose to incorporate this situation microscopy ofthe major palpal setae of some Laniatores has revealed minute tubular ducts in the classification by limiting the family to the like those illustrated here. A more compre- Ischyropsalididae only genus Ischy- and a family Ceratolas- hensive survey of seta types in Opiliones is ropsalis, recognizing needed. matidae which includes four genera. The type some How many families of Ischyropsalidoidea genus was selected because there is still should there be? Dresco (1970) suggested

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