Arachnologische Gesellschaft

Taxonomy and Phylogeny of Spiders

More than 47.000 species are listed in the World Spider Catalog (2018). These are classified into 116 families. Every day new species are described and estimates reach 120.000 spider species on Earth.

Systematics of spiders (major clades) is relatively stable, but monophyly of several classic groups as well as the position of families  (and genera) in the Tree of Life are still changing according to new data and analyses and discussed steadily.

Phylogeny

Recent analyses of a transcriptome-based data set comprising 70 ingroup spider taxa led to a much better resolution of spider evolutionary relationships (Garrison et al. 2016).  Previous incongruences between the traditional spider classification scheme and (non-phylogenomic) molecular systematics appear to be caused by just too few data. Non-molecular datasets to date have been restricted to a relatively small set of morphological and/or behavioral characters whereas molecular analyses addressing deep spider relationships have largely employed relatively few, rapidly evolving loci (Garrison et al. 2016).

The new phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. On the other hand, they question the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified and traditional Haplogynae is in need of revision. Many families were still not included and several positions remain uncertain.

Some important new perceptions

Palaeocribellatae include only one recent family (Hypochilidae) and Neocribellatae all other Araneomorphae (with venom glands reaching into the prosoma).

The orb web originated earlier than previously supposed, but got lost at least three times independently.

Contrary to the contemporary paradigm that the evolution of the orb web and adhesive
sticky threads elevated rates of diversification among the araneoid spiders, the new analysis indicates that the highest rates of diversification likely occurred among the RTA spiders followed by mygalomorphs and then araneoids as a distant third, the latter driven–in part–by the secondarily non-orb weaving theridiids and linyphiids.

This interestingly implies that other foraging strategies like cursorial hunting and irregular sheets were a more ‘‘successful’’ strategy than the orb, probably related to the enormous diversification of insects (among them litter inhabiting ants and beetles) during the Cretaceous Terrestrial Revolution.

Literature (Selection)

Agnarsson, I., Coddington, J.A. & Kuntner, M. (2013) Progress in the study of spider diversity and evolution. In: Penney D (Hrsg.) Spider Research in the 21st Century. Siri Scientific Press, Manchester. pp. 58–111.

Alfaro, R.E., Griswold, C.E. & Miller, K.B. (2018) ­Comparative spigot ontogeny across the spider tree of life. PeerJ, 6, e4233.

Agnarsson, I., Coddington, J.A. & May-Collado, L.J. (2007) Elongated pedicillate setae: A putative sensory system and synapomorphy of spiders. Journal of Arachnology, 35, 411–426.

Blackledge, T.A., Scharff, N., Coddington, J.A., Szüts, T., Wenzel, J.W., Hayashi, C.Y. & Agnarsson, I. (2009) Reconstructing web evolution and spider diversification in the molecular era. - Proceedings of the National Academy of Sciences of the United States of America 106: 5229–5234.

Bond, J.E., Garrison, N.L., Hamilton, C.A., Godwin, R.L., Hedin, M. & Agnarsson, I. (2014) Phylogenomics Resolves a Spider Backbone Phylogeny and Rejects a Prevailing Paradigm for Orb Web Evolution. Current Biology, 24, 1765–1771.

Coddington, J.A. (2005) Phylogeny and classification of spiders. In: Ubick, P., Paquin, P., Cushing, P. & Roth, V. (Hrsg.) Spiders of North America: an identification manual. American Arachnological Society. pp. 18–24.

Coddington, J.A., Agnarsson, I., Cheng, R.-C., Čandek, K., Driskell, A., Frick, H., Gregoric, M., Kostanjsek, R., Kropf, C., Kweskin, M., Lokovsek, T., Pipan, M., Vidergar, N. & Kuntner, M. (2016) DNA barcode data accurately identify higher taxa. PeerJ PrePrints, 4, e1633v1631.

Garrison, N.L., Rodriguez, J., Agnarsson, I., Coddington, J.A., Griswold, C.E., Hamilton, C.A., Hedin, M., Kocot, K.M., Ledford, J.M. & Bond, J.E. (2016) Spider phylogenomics: untangling the Spider Tree of Life. - PeerJ 4: e1719 - doi: 10.7717/peerj.1719

Griswold, C.E., Coddington, J.A., Hormiga, G. & Scharff, N. (1998) Phylogeny of the orb-web building spiders (Araneae, Orbiculariae: Deinopoidea, Araneoidea). - Zoological Journal of the Linnean Society 123: 1–99.

Griswold, C.E. & Ramírez, M.J. (2017) Phylogeny of Spiders. In: Ubick, D., Paquim, P., Cushing, P.E. & Roth, B. (eds.): Spiders of North America: an identification manual, 2nd Edition. American Arachnological Society, Keen, New Hamshire, USA: 17-29.

Griswold, C.E., Ramírez, M.J., Coddington, J.A. & Platnick, N.I. (2005) Atlas of Phylogenetic Data for Entelegyne Spiders (Araneae: Araneomorphae: Entelegynae) with Comments on Their Phylogeny. - Proceedings of the California Academy of Sciences 56: 1–324.

Huang, D., Hormiga, G., Cai, C., Su, Y., Yin, Z., Xia, F. & Giribet, G. (2018) Origin of spiders and their spinning organs illuminated by mid-Cretaceous amber fossils. Nature Ecology & Evolution.

Jocqué, R. & Dippenaar-Schoeman, A. (2007) Spider families of the world. 2nd edition. 1–336.

Kuntner, M. & Coddington, J.A. (2009) Discovery of the largest orbweaving spider species: The evolution of gigantism in Nephila. - PLoS ONE 4: 2–6.

Penney, D. (2013) Spider Research in the 21st Century - trends & perspectives. Penney D (Hrsg.). Siri Scientific Press, Manchester. 1-320 pp.

Platnick, N.I., Coddington, J.A., Forster, R.R. & Griswold, C.E. (1991) Spinneret morphology and the phylogeny of haplogyne spiders (Araneae, Araneomorphae). - American Museum Novitates 3016: 1–73.

Ramírez, M.J. (2014) The morphology and phylogeny of dionychan spiders (Araneae, Araneomorphae). - Bulletin of the American Museum of Natural History 390: 1–374.

Shear, W.A., Palmer, J.M., Coddington, J.A. & Bonamo, P.M. (1989) A Devonian spinneret: early evidence of spiders and silk use. - Science series American Museum of Natural History 246: 479–481.

Wang, B., Dunlop, J.A., Selden, P.A., Garwood, R.J., Shear, W.A., Müller, P. & Lei, X. (2018) Cretaceous arachnid Chimerarachne yingi gen. et sp. nov. illuminates spider origins. Nature Ecology & Evolution.

Wheeler, W.C., Coddington, J.A., Crowley, L.M., Dimitrov, D., Goloboff, P.A., Griswold, C.E., Hormiga, G., Prendini, L., Ramírez, M.J., Sierwald, P., Almeida-Silva, L., Alvarez-Padilla, F., Arnedo, M.A., Benavides, L.R., Benjamin, S.P., Bond, J.E., Grismado, C.J., Hasanf, E., Hedin, M., Izquierdo, M.A., Labarque, F.M., Ledford, J., Lopardo, L., Maddison, W.P., Miller, J.A., Piacentini, L.N., Platnick, N.I., Polotow, D., Silva-Dávila, D., Scharff, N., Szűts, T., Ubick, D., Vink, C.J., Wood, H.M. & Zhang, J. (2016) The spider tree of life: Phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling. - Cladistics: 1–43. doi: 10.1111/cla.12182