20th International Congress of Arachnology

DENVER MUSEUM OF NATURE & SCIENCE

REPORTS

No. 3, July 2, 2016

in the Fichtel Mountains (Upper Franconia, NE Bavaria,

Germany). The mountains are of Variscan origin (380-280

my old) and the rocks are mainly Granite. The sloping

blockfields contain mainly large rocks (>1m). Knowing of

single species specialized on such habitats from the region

(

Clubiona alpicola, Sitticus saxicola, Acantholycosa

norvegica, Choleva lederiana

), we expected to find more

specialists and at more sites. A pre-study confirmed this

estimation. A variety of sites was selected, with the focus

on the natural sloping blockfields (felsenmeer). But we

also included artificial sites (from mining) as well as rocky

sites and adjacent forested or grassland sites. The altitude

range was from 560m to 1050m, with most sites between

800 to 1040m. Besides the spiders, some beetle-groups,

harvestmen, pseudoscorpions, and snow flies (

Chionea

)

are determined to species level. Several spider species spe-

cialized on talus habitats were found, also several species

which live only at higher elevations. Mostly the typical talus

spiders live also in other habitats in the Alps over 2000m.

One species (

Bathyphantes eumenis buchari

) is not

known from the Alps and has its origin in stony (riparian)

habitats in Siberia and the Arctic. Together with some other

species, it is judged to be a glacial relict (peri- or postgla-

cial). These species are all endangered by current climate

change. A classification of the recorded spider species and

coenoses was made according to various parameters: total

distribution, threatened status in Germany, frequency in

Germany, stenotopy, naturalness of its preferred habitats.

These data confirm the specialness of the talus habitats,

even compared with adjacent rocky and other sites.

Keywords: spiders, Germany, mountains, blockfield,

specialists

Oral presentation

Historical refugia have shaped biogeogra-

phy of dispersal-limited mite harvestmen

(Opiliones, Cyphophthalmi) from the

Australian wet tropics

Sarah L. Boyer

, Tricia M. Markle

, Caitlin M. Baker

Amy M. Luxbacher

, Ken H. Kozak

Biology Department, Macalester College, 1600 Grand

Avenue, Saint Paul, Minnesota 55105, USA;

Department

of Fisheries, Wildlife, and Conservation Biology, University

of Minnesota, Saint Paul, Minnesota 55108, USA;

Depart-

ment of Organismic and Evolutionary Biology, Harvard

University, 26 Oxford St., Cambridge, MA 02138, USA

boyer@macalester.edu

How did Pleistocene glacial cycling affect the diversity of

rainforest life? Over the past several decades, biologists

have tested the hypothesis that forest contraction and

fragmentation drove speciation in rainforest animals,

concluding that in most cases species-level divergences

predate the Pleistocene. More recently, focus has turned

to the role of Pleistocene refugia in preserving lineages,

effectively acting as “museums” of biodiversity. We tested

this model in a lineage of tiny dispersal-limited mite

harvestmen (Opiliones, Cyphophthalmi) distributed

throughout in the rainforests of the Australian wet tropics.

We generated a model of habitat suitability for the genus

Austropurcellia and projected it onto paleoclimate data

layers dating back to the Last Glacial Maximum (LGM).

We compared the power of present-day and past distribu-

tion of suitable climatic conditions to predict present-day

distribution of diversity across subregions of the Wet

Tropics. We found that the distribution of suitable climatic

conditions during the LGM is the best predictor of both

number of species and phylogenetic diversity in our study

system, outperforming current distribution of suitable cli-

matic conditions. This finding is consistent with a model

in which historical refugia have played a significant role

in establishing present-day biogeographic patterns.

Keywords: biogeography, Opiliones, phylogeny, species

richness

Oral presentation

On the track of the wolf: systematics of

North American species described in the

genus

Lycosa

Allen Brady, Lauren Fogg

Department of Biology, Hope College, Holland, MI 49423

brady@hope.edu

A brief synopsis of continuing research focused upon the

systematic relationships of North American species of

International Congress of Arachnology