20th International Congress of Arachnology

161

DENVER MUSEUM OF NATURE & SCIENCE

REPORTS

No. 3, July 2, 2016

Switzerland;

Natural History Museum Bern, Depart-

ment of Invertebrates, CH-3005 Bern, Switzerland;

Institute of Anatomy, Department of Topographic

and Clinical Anatomy, University of Bern, CH-3012

Bern, Switzerland

miguel.richard@iee.unibe.ch

The genus

Ischnothyreus

Simon, 1893 from Java and

Sumatra is revised with the description of seven new

species from Java (

I. baltenspergerae

sp. nov.,

I. bauri

sp.

nov.,

I. gigeri

sp. nov.,

I. ligulatus

sp. nov.,

I. nentwigo-

rum

sp. nov.,

I. sigridae

sp. nov.,

I. ujungkulon

sp. nov.)

and eight from Sumatra (

I. ascifer

sp. nov.,

I. concavus

sp. nov.,

I. habeggeri

sp. nov.,

I. haymozi

sp. nov.,

lucidus

sp. nov.,

I. marggii

sp. nov.,

I. microphthalmus

sp. nov.,

I. obscurus

sp. nov.). Furthermore the male of

serpentinum

Saaristo, 2001 is described for the first time.

Special morphological features of

Ischnothyreus

males

and females are described and discussed, such as peculiar

trochanter projections, partially fused pedipalp segments,

processes on the cheliceral fang base in males and exter-

nal and internal genitalic structures in females. All species

are diagnosed, described and illustrated. This work is part

of the planetary biodiversity inventory (PBI) project of

goblin spiders

( http://research.amnh.org/oonopidae/ )

Keywords: genitalia, morphology, PBI, taxonomy

Student - oral presentation

Glacial refugia and riverine barriers:

biogeography of

Acuclavella

(Opiliones,

Ischyropsalidoidea) in Northern Idaho

*Casey H. Richart, Marshal Hedin

San Diego State University 5500 Campanile Drive

San Diego, CA 92182, USA

pileated@gmail.com

The utility of Opiliones to infer world-wide biogeographic

patterns has long been realized, but the potential for these

often poor dispersers to inform evolutionary processes at

more shallow time scales is still underappreciated. Here we

analyze a phylogenomic data set of over 5201 variable loci

(5156 unlinked SNPs) generated via ddRAD sequencing to

report on the biogeography of the Thorn Harvestmen

Acu-

clavella

(Dyspnoi, Ischyropsalidoidea) from the Western

Hemlock Zone of the Pacific Northwest, United States. The

Western Hemlock Zone has a complex recent evolution-

ary past, with Cascade orogeny, Pleistocene refugia, and

riverine barriers all interacting to shape its biogeographic

history. Here we test several hypotheses on the effects of

Pleistocene refugia and riverine barriers on diversification

events between the

Acuclavella

species of northern Idaho.

Namely, we predict that (1) diversification events within

Acuclavella

are associated with refugia and rivers, (2)

inferred ancestral population sizes of Acuclavella species

will show bottlenecks corresponding temporally with the

Last Glacial Maximum, and (3) genetic diversity will be

higher in refugia, with a phylogenetic “leading edge”

model showing expansion out of refugia. This research

provides important and novel insights into the role of

Pleistocene glacial cycles and rivers in shaping the biodi-

versity of the Western Hemlock Zone of northern Idaho.

More broadly, this research highlights the significant

contributions that studying poorly dispersing denizens of

forest litter can have for biogeographic inquiries.

Keywords: biogeography, Pleistocene refugia, riverine

barriers, ddRAD, Opiliones, evolution

Poster presentation

First offering: spider identification field

course, Southwestern Research Station of the

American Museum of Natural at Portal AZ

contributes to species records for the area

David B. Richman

, Susan Riechert

, Barbara Roth

Ann Kronk

New Mexico State University, Dept. of Entomology, Plant

Pathology and Weed Science, Las Cruces, NM 88003,

USA - Current Address: P. O. Box 1653, Edmonds, WA

98020, USA;

Ecology and Evolutionary Biology, 520

Hesler Biology Bldg., University of Tennessee, Knoxville,

TN 37996, USA;

Southwestern Research Station, P.O. Box

16553, Portal, AZ 85632, USA;

Natural and Behavioral

Sciences, Pellissippi State Community College, 10915

Hardin Valley Rd, Knoxville, TN 37932, USA

rdavid@nmsu.edu

A field course in spider collection and identification

was offered at the Southwestern Research Station in the

International Congress of Arachnology