Abstract
The Plectreuridae is a relatively small, ecribellate, haplogyne spider family consisting of only two extant genera. Kibramoa Chamberlin has seven described species restricted to the USA and Mexico (Gertsch 1958) and Plectreurys Simon is known from 22 species, with similar distributions (Gertsch 1958, Jiménez 2006), but also including Cuba and Costa Rica (Alayón 1993, 2003). In addition, a single fossil species Palaeoplectreurys baltica Wunderlich, known only from the holotype, has been described from the Eocene Baltic amber of Europe (Wunderlich 2004). Additional fossils are known from the Jurassic of China and these are currently being described by Selden (pers. comm. 2009), who also questions the placement of Palaeoplectreurys Wunderlich in this family. Thus, the extant forms may represent relicts of a family more widespread in the past. Little is known about the biology of this family, although they are unusual among ecribellate haplogynes in possessing eight, rather than six eyes. They are nocturnal, hunting spiders, which live in a silken tube that they seldom leave, rather like the closely related Segestriidae (Gertsch 1958). However, males leave their tube upon maturity to go in search of females, at which point they become more susceptible to entrapment in tree resin seeps (Penney 2002). The tibia of leg 1 in males of Plectreurys has a distinctive stout retrolateral process towards the distal end, which bears a strong spine. These coupling spurs, which are absent in Kibramoa and Palaeoplectreurys are presumed to be used for restraining or positioning the female during mating.
References
Alayón, G.G. (1993) Redescripción de Plectreurys globosus Franganillo (Araneae: Plectreuridae). Poeyana, 429, 1–7.
Alayón, G.G. (2003) Nueva especie de Plectreurys Simon (Araneae: Plectreuridae) de Cuba. Revista Iberica de Aracnologia, 7, 85–88.
Betz, V. and Green, D.I. (2007) Digitale Kombinations-fotografie von Kleinmineralien und Micromounts. Lapis, 32, 22–32.
Dierick, M., Cnudde, V., Masschaele, B., Vlassenbroeck, J., Van Hoorebeke, L. and Jacobs, P. (2007) Micro-CT of fossils preserved in amber. Nuclear Instruments and Methods in Physics Research A, doi,10.1016/j.nima.2007.05.030
Gertsch, W.J. (1958) The spider family Plectreuridae. American Museum Novitates, 1920, 1–53.
Green, D.I. (2005) Digital combination photography: A technique for producing improved images of microscopic minerals. Australian Journal of Mineralogy, 11, 13–24.
Grimaldi, D.A. and Engel, M.S. (2005) Evolution of the insects. Cambridge University Press, New York, 772 p.
Hormiga, G., Alvarez-Padilla, F. and Benjamin, S.P. (2007) First records of extant Hispaniolan spiders of the families Mysmenidae, Symphytognathidae, and Ochyroceratidae (Araneae), including a new species of Ochyrocera. American Museum Novitates, 3577, 1–21.
Iturralde-Vinent, M.A. (2001) Geology of the amber-bearing deposits of the Greater Antilles. Caribbean Journal of Science, 37, 141–167.
Iturralde-Vinent, M.A. and MacPhee, R.D.E. (1996) Age and palaeogeographical origin of Dominican amber. Science, 273, 1850–1852.
Jiménez, M.-L. (2006) Description of the male of Plectreurys arida (Araneae: Plectreuridae). Journal of Arachnology, 34, 495–497.
Martínez-Delclòs, X., Briggs, D.E.G. and Peñalver, E. (2004) Taphonomy of insects in carbonates and amber. Palaeogeography, Palaeoclimatology, Palaeoecology, 203, 19–64.
Penney, D. (2002) Paleoecology of Dominican amber preservation—spider (Araneae) inclusions demonstrate a bias for active, trunk-dwelling faunas. Paleobiology, 28, 389–398.
Penney, D. (2008) Dominican Amber Spiders: a comparative palaeontological-neontological approach to identification, faunistics, ecology and biogeography. Siri Scientific Press, Manchester, 176 p.
Penney, D., Dierick, M., Cnudde, V., Masschaele, B., Vlasssenbroeck, J., Van Hoorebeke, L. and Jacobs, P. (2007) First fossil Micropholcommatidae (Araneae), imaged in Eocene Paris amber using X-Ray Computed Tomography. Zootaxa 1623, 47–53.
Pérez-Gelabert, D.E. (2008) Arthropods of Hispaniola (Dominican Republic and Haiti): a checklist and bibliography. Zootaxa, 1831, 1–530.
Platnick, N.I. (2009) The world spider catalog, version 9.5. American Museum of Natural History, online at http://research.amnh.org/entomology/spiders/catalog/index.html
Platnick, N.I. and Penney, D. (2004) A revision of the widespread spider genus Zimiris (Araneae, Prodidomidae). American Museum Novitates, 3450, 1–12.
Rheims, C.A. and Brescovit, A.D. (2004) Revision and cladistic analysis of the spider family Hersiliidae (Arachnida, Araneae) with emphasis on neotropical and nearctic species. Insect Systematics and Evolution, 35, 189–239.
Wunderlich, J. (ed.) (2004) Fossil spiders in amber and copal. Beiträge zur Araneologie, 3a, 1–850.