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Accepted by P. Schwendinger: 25 Jul. 2006; published: 28 Sept. 2006 191
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Copyright © 2006 Magnolia Press
Zootaxa 1325: 191–198 (2006)
www.mapress.com/zootaxa/
Martensolasma jocheni, a new genus and species of harvestman
from Mexico (Opiliones: Nemastomatidae: Ortholasmatinae)
WILLIAM A. SHEAR
Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943 USA.
E-mail: wshear@hsc.edu
Abstract
Martensolasma jocheni n. g., n. sp. is described from the Mexican State of Aguascalientes. The
new genus is distinct from Dendrolasma Banks and Ortholasma Banks in lacking the extensive
modifications of the eye tubercle.
Key words: Aguascalientes, Ortholasma, Crosbycus, Nemastomatinae, Ceratotlasmatidae
Introduction
The Nemastomatidae harvestman subfamily Ortholasmatinae was erected in 1983 by
Shear & Gruber for nine North American and one Japanese species formerly of uncertain
taxonomic position; they previously had been considered members of Trogulidae (Banks
1894, Roewer 1923, Goodnight and Goodnight 1942), Ischyropsalididae (Goodnight &
Goodnight 1945) or Dicranolasmatidae (Silhavy 1967, Suzuki 1974). Martens (1969)
correctly placed them in Nemastomatidae. The members of the subfamily were
characterized (Shear & Gruber 1983) as bearing a hood overhanging and concealing the
chelicerae and palpi, formed from an extension of the eye tubercle and one or two lateral
processes from the margin of the dorsal shield on each side; cuticular sculpture consisting
of a series of cells covering the dorsum and formed from keels and keel pegs derived from
extended and fused anvil-shaped teeth, and the long, acute glans of the penis in males.
Since their monographic study, little new information has been published, save for the
description of a fourth species of Dendrolasma, from Thailand (Schwendinger & Gruber
1992). Also, Shear and Gruber later (1987) found that their species Ortholasma setulipes
was a synonym of O. coronadense Cockerell 1916.
Previously known species of Dendrolasma came from Japan and from northwestern
SHEAR
192 © 2006 Magnolia Press
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ZOOTAXA North America. The genus Ortholasma is known only from North America, with six
species ranging from central Mexico to northern Vancouver Island, British Columbia,
Canada (maps in Shear & Gruber 1983). A number of new species of Ortholasma from
Mexico and California await description, as well as one which extends the subfamily’s
range into Honduras.
The new genus and species described below represents a departure from the characters
previously regarded as significant in this group and requires that the subfamily be
rediagnosed.
Taxonomy
Family Nemastomatidae Simon 1872
Subfamily Ortholasmatinae Shear & Gruber 1983
Emended diagnosis: Nemastomatidae with flattened dorsum, free opisthosomal tergites
shifted ventrally, with or without hood formed from forward-projecting eye tubercle and
lateral processes of dorsal shield, scutum parvum ranging to scutum magnum, dorsal
sculpture of keel cells formed by exaggerated and fused two to five-branched tubercles.
Chelicerae of males with basofrontal tooth on second article, epigamic gland of first article
present or absent. Palpi short, numbers of glandular setae reduced in adults, palpi of males
sometimes with epigamic glandular apparatus in tibiae, pataellae or femora, and
sometimes with distal patellar teeth. Legs short, tarsomeres relatively few. Penis simple,
glans not well-differentiated from shaft, with long stylus tapering directly into acute tip,
setation monomorphic or dimorphic.
Martensolasma n. g.
Type species: Martensolasma jocheni n. sp.
Diagnosis: Distinct from Ortholasma and Dendrolasma in lacking a hood projecting
over the chelicerae, and in exhibiting complete scutum magnum. Leg femora with few or
no pseudoarticulations. Penial setation monomorphic, consisting of few very small, acute
setae. Male chelicerae with tooth-like projections on proximal and median articles. Male
pedipalpi with epigamic glands in patellae and tibiae.
Etymology: The name of the genus is neuter and represents a combination of the
name Martens with ‘-lasma,” a combining suffix used in this subfamily.
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ORTHOLASMATINAE
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ZOOTAXA
Martensolasma jocheni n. sp.
Figs 1–14
Types: Male holotype and male paratype from Ciudad Aguascalientes, Aguascalientes,
Mexico, collected under stones in a garden by James C. Cokendolpher, 5 January 1977,
deposited in Museum of Comparative Zoology, Harvard University, Cambridge MA,
USA.
Etymology: The species epithet honors Jochen Martens on the occasion of his
retirement, in recognition of his many contributions to our knowledge of the systematics
and evolution of the Opiliones, and with pleasant memories of excursions in the Great
Smoky Mountains of North Carolina and in the Italian Dolomites.
Male holotype: About 2 mm long. Dorsum (Fig. 1) glossy black, unmarked; venter
black with some dark brown areas at sternal margins. Leg articles black, but most articles
yellow to chestnut brown proximally, giving effect of light banding. Scutum magnum
present (dorsal shield of prosoma, thoracic tergites and opisthosomal scute fused into
single dorsal shield). Eye tubercle without hood, circumocular keels small, eyes visible
dorsally (Fig. 2). Single lateral process on each side of dorsal shield connected to anterior
marginal keel. Cells defined by keels (some cells not completely enclosed) as follows:
Two large cells lateral to eye tubercle, single smaller cell (open posteriorly) directly
posterior to eye tubercle. More posterior cells aligned roughly in six transverse rows. First
two rows with incomplete cells; first row with slightly indicated boundaries of two small
lateral cells, larger median cell, second row without clear division of cells. Third row with
five roughly subequal cells, boundaries sometimes incomplete. Fourth row with single
large median cell about five times as wide as long, partially divided by two keels, two
lateral cells each about one-third width of median cell. Fifth row with median cell divided
by keels into three smaller cells, these subequal to two lateral cells. Sixth row of five
approximately subequal cells. Keel pegs with projecting spines becoming more prominent
posteriorly, eventually forming row of strong, subacute processes on posterior margin of
scute (Fig. 3); keel arms strongly recurved, fused to dorsum and arms of adjacent pegs,
producing series of loops most obviously seen in dorsal view along lateral margins of
scute (Fig. 4). Keel pegs typically with two or three such keel arms. Genital operculum
apically narrowed, tongue-like. Sterna with rows of tubercles, but lacking keels and keel
pegs.
Chelicera (Fig. 6) with basal article distinctly humped, bearing acute, curved mesal
tooth; distal article as usual for subfamily, bearing mesoproximal curved, acute tooth, area
of slightly denser setation mesoproximal to tooth indicating presence of cheliceral
epigamic gland (not possible to determine in absence of comparison with females, see also
Discussion below).
Pedipalpus (Fig. 7) small, short, with reduced vestiture of glandular hairs. Femur
slender, basally with three tubercles bearing blunt ordinary setae, less than 15 glandular
setae scattered over ventral surface; patella slightly shorter than femur, thickened ventrally
SHEAR
194 © 2006 Magnolia Press
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ZOOTAXA in its ventrodistal half, thickened region with dense vestiture of acute nonglandular setae,
probably indicating presence of palpal epigamic gland (females not available for
comparison); tibia about four fifths length of patella, basally swollen, with setae that
indicate possible epigamic gland, vestiture of glandular setae more dense; tarsus about half
length of tibia, distally rounded, claw absent, much denser vestiture of glandular setae than
tibia, glandular setae mixed with ordinary setae toward distal end.
FIGURES 1–5. Scanning electron micrographs of Martensolasma jocheni n. g. n. sp., paratype
male. 1 Habitus of whole animal. 2 Eye tubercle and anterior part of dorsal shield. 3 Keel and posts
from posterior scute margin. 4 Lateral marginal keel of anterior part of scute. 5 Ornamentation of
third metatarsus (1–4 dorsal view, 5 lateral view).
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ORTHOLASMATINAE
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FIGURES 6–14. Martensolasma jocheni n. g. n. sp., paratype male. 6 Left chelicera, mesal view. 7
Right palpus, lateral view. 8–11 Legs in lateral view (8 leg 1, 9 leg 2, 10 leg 3, 11 leg 4; scale line
above Fig. 11). 12 Leg 1, lateral view, showing detail of ornamentation. 13 Penis, dorsal view. 14
Distal portion of penis with glans, dorsal view.
Legs (Figs 8–11) in order of length: 2, 4, 3, 1. Coxae with distal marginal keel pegs
and keels, coxae 1 and 4 with marginal keels on anterior and posterior surfaces,
respectively. Trochanters with ventral tubercles bearing blunt setae. Femora distally
expanded, third and fourth femora with single pseudoarticulation about one-sixth their
length from articulation with trochanters. Patellae tending to subglobular, no more than
twice as long as wide. Tibiae short, one and one half to twice as long as patellae. Metatarsi
longest leg segments, nearly cylindrical, without pseudoarticulations, about twice length
of tibiae except on second legs, where almost four times length of tibiae. Tarsal articles of
first and third legs four, second legs with five; third article of fourth leg tarsi with single
pseudoarticulation, giving appearance of five articles. Leg vestiture (Figs 5, 12) complex;
femora basally smooth in pale colored region, more distally with closely appressed, acute,
flattened tubercles evenly scattered over surface, small blunt setae on low, rounded cones.
SHEAR
196 © 2006 Magnolia Press
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ZOOTAXA On patellae and tibiae, tubercles reduced, suppressed, setae present. Metatarsi lacking
tubercles, densely covered with fine, short, hair-like trichomes and scattered, longer, thin,
nearly filamentous setae, curved or curled distally. Tarsal articles with same dense, short
setae, on fourth legs also with few curled, longer setae basally.
Penis (Figs 13–14) long, narrow, shaft slightly widened distally, glans without any
obvious dorsal membranous area, narrowing somewhat abruptly to stylus; stylus slightly
sigmoid at tip, not strongly curved or hook-shaped, opening terminal. Base of stylus with
six small setae, otherwise glans without setation.
Physical dimensions of the described specimen may be ascertained from the figures,
using the appropriate scale lines.
Discussion
The discovery of the new species in a garden opens the possibility that it is not native to
Aguascalientes. The only imported species of Nemastomatidae in the New World is
Nemastoma bimaculatum, which has evidently become established on Mont Royal,
Montreal, Quebec (LeSage 1977). No other instances are on record of alien
Nemastomatidae establishing themselves. Martensolasma jocheni superficially resembles
a Nemastomatinae, because unlike other known species of Ortholasmatinae, it lacks the
conspicuously modified eye tubercle. However, the penis of the species conforms to the
type found in other Ortholasmatinae (rare in Nemastomatinae), the unusual ornamentation
of the subfamily (dorsum divided into cells by keels and keel posts) is present, and the
males have acute, tooth-like processes on the proximal and median articles of the
chelicera. Further, the prominent, projecting cheliceral gland process found in most
Nemastomatinae males is lacking. The evidence is convincing that M. jocheni is an
Ortholasmatinae, and likely to be native to Aguascalientes. Giribet et al. (2002) included
“Ortholasma sp.” in a cladistic analysis of opilionid relationships, using both molecular
and morphological data, and confirmed that Ortholasmatinae are most closely related to
Nemastomatinae.
Martensolasma jocheni has a number of features besides the relatively unmodified eye
tubercle that set it well apart from the other Ortholasmatinae, and it appears the most
divergent element in the subfamily. The keels of the dorsum differ from those found in, for
example, Ortholasma species in that the arms of the keel pegs are very thick and stout (see
illustrations of Ortholasma in Shear & Gruber 1983) and are strongly recurved, forming a
series of loops that are most obvious in dorsal view along the lateral margins of the body.
The small number of cells and their more regular arrangement is also unlike the situation
in many other species of the subfamily, where most larger cells are divided up into
irregular smaller ones by additional keels.
As for the legs, the presence of a single femoral pseudoarticulation on legs three and
four separates this species from Ortholasma species, which lack pseudoarticulations, as
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ORTHOLASMATINAE
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well as from Dendrolasma,species, where they are numerous. The complete absence of
pseudoarticulations in the leg metatarsi is unlike the situtation in other Ortholasmatinae,
where there are several in the second metatarsi and frequently in the metatarsi of other
legs. The ornamentation of the metatarsi with semiprocumbent, long, curled hairs is
superficially similar to leg vestiture in the Ceratolasmatidae Crosbycus dasycnemus
(Crosby). However, the curled “hairs” in C. dasycnemus are actually the unsocketed
trichomes, while those of M. jocheni are socketed setae (see Fig. 12 in Shear 1986), and
the genera belong in two distinct superfamilies (Shear 1986). A re-examination of the
undescribed species of Ortholasma from Mexico show that some of them also have the
curled hairs; similar hairs standing above the other vestiture in other species are not curled.
There is a possibility that somehow the curling of these hairs is an effect of preservation,
but the preservational history of the specimens is not known.
While Shear & Gruber (1983) inferred the presence of sexually dimorphic glands on
the pedipalpi of male Ortholasmatinae from their swollen outlines, their presence in M.
jocheni is made obvious by the groups of small setae, and in one of the two males, by caps
of secretion that still adhered to these places even after long preservation. The evidence for
a male cheliceral gland in this species is less clear, as there are no obvious modifications of
the basal article, as seen, for example, in Ortholasma levipes Shear & Gruber and O.
rugosum Banks, where a dense patch of small setae on the basal article marks the position
of the gland. The absence of the gland in other Ortholasmatinae was considered
apomorphic by Shear & Gruber in their cladistic analysis of the family, since all
Nemastomatinae have the gland.
Acknowledgements
I thank James Cokendolpher for sending me the specimens that have become the types of
Martensolasma jocheni, and apologize to him that it has taken nearly 25 years to describe
them! Thanks to Jason Bond for the use of the Scanning Electron Microscope facility at
Eastern Carolina University, and to Matt Walker for assistance in operating the
microscope. Peter Jäger has my thanks for inviting me to participate in this Festschrift for
my friend, Jochen Martens. Comments on the manuscript by Jürgen Gruber, Peter
Schwendinger and Peter Jäger were extremely helpful. Asa Kreevich provided sage
guidance and advice.
This research was carried out under the auspices a grant to author by the Professional
Development Committee of Hampden-Sydney College.
References
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SHEAR
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ZOOTAXA Cockerell, T. (1916) A new phalangid from the Coronados Islands. Entomological News, 27, 158.
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Goodnight, C.J. & Goodnight, M. (1942) Phalangida from Mexico. American Museum Novitates,
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Goodnight, C.J. & Goodnight, M. (1945) A representative of the Ischyropsalidae from Mexico.
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Roewer, C.-F. (1923) Die Weberknechte der Erde. Gustav Fischer, Jena, 1116 pp.
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