Staff Profile

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Petra Sierwald

Associate Curator

Negaunee Integrative Research Center

Main Research Interest:

Evolutionary Biology; biodiversity, phylogeny, biogeography and systematics of Arthropoda, especially Arachnida and Myriapoda; morphological evolution, museum collections analyses

Research: Collections-based biodiversity research in Arachnida and Myriapoda, contributing to species discovery and higher level phylogenies, and to the analysis of complex and new morphological characters suites for phylogenetic research as well as to the development of taxonomic tools. Research strategies address the vastly different knowledge-base in Arachnida on one hand and Myriapoda on the other, with nearly all research in integrative and collaborative arrangements (e.g., millipede phylogenomics research grant). Curation and Education:

Specimen and tissue collection building, improvement of collection accessibility (e.g., NSF TCN grant) and stewardship of data, specifically building the first global and fully referenced millipede species database. Research and biodiversity-centered training at various levels (e.g., REU site grants), advising US-based and international graduate students, and outside grant-funded postdoctoral training are important components of my professional portfolio.

Recent Blog Posts

Additional Information


Degrees held: Ph.D. (Dr. rer. nat.) in Zoology, University of Hamburg; 1985.

M.Sc. (Staatsexamen) in Biology, Geography and Biology-Education; University of Hamburg; 1982.

Grants & awards

NSF: EF-Digitization: 14-02667. Collaborative Research: Digitization TCN: InvertEBase, Awarded amount: $2.2mill, Field Museum portion: $870,000. Sierwald Lead PI, with co-PI R. Bieler.

NSF: DEB: 12-56150. Collaborative Proposal: Millipede phylogenomic, Sierwald Co-PI [FMNH portion $201,780], Lead: former postdoc Dr. J. Bond

NSF: DBI 11-56594, REU site grant at the Field Museum: Access to Global Biodiversity Studies for Undergraduates. Lead PI , with co-PI K.Angielczyk (Geology), [$286,405]

2009: NSF: DBI 08-49958, REU site grant at the Field Museum: Networked Access to Systematic Resources for Undergraduates in Chicagoland. PI, with co-PI P. Makovicky (Geology) [$ 258,464]. 2009: NSF: Future Directions in Biodiversity and Systematics, NSF DEB-09-35231, to P. Herendeen (Chicago Botanic Garden), L.McDade and P. Sierwald [$99,817]. 2006: NSF: DEB-PBI 06-13772: Spider Family Oonopidae (as Co-PI, with Drs. N.I. Platnick, AMNH) and C. E. Griswold (CAS). [$2,460,000, FMNH subaward $62,000]. 2005: NSF, DEB – PEET DEB 05-29715: The Diplopoda: systematics research, training and tools. Lead PI [$745,000]. 2005: NSF: DEB 05-43766Workshop on Understanding Species Diversity on Earth [$55,410]. 2002: NSF DEB-02-28690, as Co-PI (FMNH subaward $59,672), with PI W. Wheeler (AMNH), G. Hormiga (GWU), J. Coddington (SI, and L.Prendini (AMNH); Assembling the Spider Tree of Life: [$2,993,624].  1998 – 2005: NSF-PEET DEB 97-12438: The Diplopoda: Research, Taxonomic Training and Computerization Lead PI [$ 919,384].  June 2002: NSF DEB 02-27440, with Co-PI R. Bieler. Organization of NSF workshop at FMNH: NEON V- Cripton.. See at: June 1994 – May 1998: NSF; as Co-PI (with Dr. Peter Crane as PI); DEB 93-7449. Project Training for Undergraduates in Collections-based Analysis of Biological Diversity. [ $164,369]. 195-198: Several pre-and postdoctoral grants from the German Science Foundation DFG. NATO, Smithsonian Institution, and the The German National Scholarship Foundation, Bonn.



Online Publication:

Sierwald, P. 2012: Education LifeDesk Taxon Pages Instructor Manual, at:

Sierwald, P. 2011: Education LifeDesk Taxon Pages Student Manual, at:

Sierwald, P. 2009. What are arachnids and myriapods? in: Grzimek’s Animal Life, Gale Cengage learning, on-line publication at:

Sierwald, P. 2009. What is an arthropod? in: Grzimek’s Animal Life, Gale Cengage learning, on-line publication at:


* denotes undergraduate students

In Review:

Silva, E LC & P Sierwald. In review. Review of the genus Rothus (Araneae: Lycosoidea: Pisauridae). African Invertebrates

In press: Silva, E LC, A Gibbons* & P Sierwald. In press. Description of the male of Dolomedes raptoroides Zhang, Zhu & Song, 2004 (Araneae: Lycosoidea: Pisauridae). Zootaxa


Powers, K. E., Prather, L. A., Cook, J. A., Woolley, J., Bart, H. L., Jr., Monfils, A. K., & Sierwald, P. (2014). Revolutionizing the use of natural history collections in education. The Science Education Review13(2), 24–33.

Marek, P, T Tanabe, P Sierwald. 2014. A species catalog of the millipede family Xystodesmidae (Arthropoda: Diplopoda: Polydesmida). Virginia Museum of Natural History Special Publication 17: i-xxi, 1-116.

Wesener, T, P Sierwald & JW Waegele. 2014. Sternites and spiracles - The unclear homology of ventral sclerites in the basal millipede order Glomeridesmida (Myriapoda, Diplopoda). Arthropod Structure & Development, 43(1): 87-95

Silva, E LC & P Sierwald. 2013. On three monotypic nursery web spider genera from Madagascar with first description of the male of Tallonia picta Simon, 1889 and redescription of the type-species of Paracladycnis Blandin, 1979 and Thalassiopsis Roewer, 1955 (Araneae: Lycosoidea: Pisauridae). Zootaxa, 3750(3): 277-288.

Barbosa, J P, P Sierwald, AD Brescovit. 2013. On the largest chelodesmid millipedes: taxonomic review and cladistics analysis of the genus Odontopeltis Pocock, 1894 (Diplopoda: Polydesmida: Chelodesmidae). Zoological Journal of the Linnean Society, 169(4): 737-764.

Nguyen, A.D. & P. Sierwald. 2013. A worldwide catalog of the family Paradoxosomatidae Daday, 1889 (Diplopoda: Polydesmida). CheckList, 9(6): 1132-1353.

Sandlin, N., M.L. Draney & P. Sierwald. 2013. Ceraticelus vesperus Chamberlin & Ivie, 1939 is a synonym of C. fissiceps (O.Pickard Cambridge, 1874 (Aranae, Linyphiidae). Arachnology, 16(3): 98-105.

Jorgensen, MC, P Sierwald, R J Mason-Gamer. 2013. A review of subspecies recognition in polydesmidan millipedes (Diplopoda, Polydesmida), with a revision of the subspecies of Euryuridae (Polydesmida, Xystodesmoidea). Zoologica Scripta, 42(3):317-326.

Brewer, MS, P Sierwald & JE Bond. 2012. Millipede taxonomy after 250 years: classification and taxonomic practices in a mega-diverse yet understudied arthropod group. PLosOne

Wongthamwanich, N., S Panha,  P Sierwald, T Wesener & K Thirakhupt. 2012. A new species of the giant pill-millipede genus Sphaerobelum Verhoff, 1924 from northern Thailand with an extensive description of molecular characters (Diplopoda: Sphaerotheriida: Zephroniidae). Zootaxa, 3220:29-43

Platnick, N.I., Abrahim, N., Álvarez-Padilla, F., Andriamalala, D., Baehr, B.C., Baert, L., Bonaldo, A.B., Brescovit, A.D., Chousou-Polydouri, N., Duprérrée, N., Eichenberger, B., Fannes, W., Gaublomme, E., Gillespie,R.G., Grismado,C.J., Griswold, C.E., Harvey, M.S., Henrard, A., Hormiga, G., Izquierdo, M.A., Jocqué, R., Kranz-Baltensperger, Y.,  Kropf, C., Ott, R., Ramírez, M.J., Raven, R.J., Rheims, C.A., Ruiz, G.S.,  Santos, A.J., Saucedo, A., Sierwald, P, Szüts, T., Ubick, D., & Wang, X.-P. 2012. Tarsal Organ Morphology and the Phylogeny of Goblin Spiders (Araneae, Oonopidae), With Notes on Basal Genera. American Museum Novitates, 3736: online

Brewer, M.S., P Sierwald & JE Bond. 2011. A generic homonym concerning chordeumatid millipedes (Arthropoda: Diplopoda) and ophellid worms (Annelida: Polychaeta). Zootaxa, 2744: 65-68.

Pitz, KM & P Sierwald. 2010. Phylogeny of the millipede order Spirobolida (Arthropoda: Diplopoda: Helminthomorpha). Cladistics,  26(5): 497-525

Wesener, T, MJ Raupach & P Sierwald. 2010. The origins of the giant pill-Millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae). Molecular Phylogenetics and Evolution, 57: 1184–1193.

Nguyen, AD &  P Sierwald. 2010. A new dragon millipedes (Polydesmida: Paradoxosomatidae, Paradoxosomatinae: Orthomorphini) from the Philippines. The Raffles Bulletin of Zoology, 58(2): 173–177

Wesener, T, I Bespalova* & P Sierwald. 2010. Madagascar's living giants: discovery of five new species of endemic giant pill-millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae: Zoosphaerium). African Invertebrates 51 (1): 133–161.

Jorgensen, M & P Sierwald 2010. Millipedes of the Caribbean: a review of the pyrgodesmid genus Docodesmus Cook with notes on potentially related genera (Polydesmida, Pyrgodesmidae). International Journal of Myriapodology, 3(1): 20-50.

Sierwald, P. 2009.  Contributions to Myriapod Taxonomy: The milliped and centiped genera and species described by Dr. Richard Lawrence Hoffman, pp113-147; in S. M. Roble and J. C. Mitchell (eds.). A Lifetime of Contributions to Myriapodology and the Natural History of Virginia: A Festschrift in Honor of Richard L. Hoffman’s 80th Birthday. Virginia Museum of Natural History Special Publication No. 16, Martinsville, VA

Wesener,T., Enghoff, H. & Sierwald, P. 2009. Review of the Spirobolida on Madagascar, with descriptions of twelve new genera, including three genera of 'fire millipedes' (Diplopoda). ZooKeys, 19: 1–128.

Wesener, T, H Enghoff, RL  Hoffman, J-W Wägele & P Sierwald.  2009. Revision of the endemic giant fire millipedes of Madagascar, genus Aphistogoniulus (Diplopoda, Spirobolida, Pachybolidae). International Journal of Myriapodology, 2(1): 15–52.

Bueno-Villegas, J, P Sierwald, A Espinosa de los Monteros. 2008. Phylogeny of the millipede genus Sphaeriodesmus Peters,1864 (Polydesmida, Sphaeriodesmidae) based on morphological characters. Organisms, Diversity and Evolution, 8(2): 99-120.

Stoev, P, P Sierwald & A Billey. 2008. An annotated catalog of the millipede order Callipodida (Arthropoda: Diplopoda). Zootaxa, 1706:1-50.

Segoli, M, R Arieli, P Sierwald, AR Harari & Y Lubin. 2007. Sexual cannibalism in the Brown Widow Spider (Latrodectus geometricus). Ethology, 114(3):279-286

Ramírez, MJ, JA Coddington,  WP Maddison, PE Midford, L Prendini, J Miller, CE Griswold, G Hormiga, P Sierwald, N Scharff, SP Benjamin & WC Wheeler. 2007.  Linking of digital images to phylogenetic data matrices using a morphological ontology.  Systematic Biology, 56(2): 283-294.

Sierwald, P & JE Bond. 2007. Current status of the myriapod class Diplopoda (millipedes): Taxonomic diversity and phylogeny. Annual Review of Entomology, 52: 401-420.

Rowe, M & P Sierwald. 2006. Morphological and systematic study of the tribe Australiosomatini (Diplopoda: Polydesmida: Paradoxosomatidea: Paradoxosomatidae) with the description of new species and a revision of the genus Australiosoma. Invertebrate Systematics, 20: 227-256.

Baxtrom, C, T Mongkolpradit, J Kasimos, LM Braune, R Weiss, P. Sierwald &  KH Ramsey. 2006. Common household spiders are not likely vectors of community-acquired Methicillin-resistant Staphylococcus aureus infections. Journal of Medical Entomology, 43(5): 962-965.

Snyder, BA, ML Draney, & P Sierwald. 2006. Development of an optimal sampling protocol for millipedes (Diplopoda). Journal of Insect Conservation 10(3): 277-288.

Sierwald, P, JE Bond & GT Gurda. 2005. The millipede type specimens in the collections of the Field Museum of Natural History (Arthropoda: Diplopoda). Zootaxa, 1005: 1-64.

Sierwald, P, ML Draney, T Prentice, F Pascoe, N Sandlin, EM Lehman, V Medland & J Louderman. 2005. The Spider Species of the Great Lakes States.  Proceedings of the Indiana Academy of Sciences, 114: 53- 148.

Wesener, T & P Sierwald. 2005. The giant pill-millipedes of Madagascar:  Revision of the genus Sphaeromimus, with a review of morphological terminology (Diplopoda, Sphaerotheriida, Sphaerotheriidae). Proceedings of the California Academy of Sciences, 56(29): 557-559.

Wesener, T & P Sierwald. 2005. New giant pill-millipede species from the littoral forest of Madagascar (Diplopoda, Sphaerotheriida, Zoosphaerium). Zootaxa, 1097: 1-60 (16 Dec. 2005)

Clark, VV, CJ Raxworthy, V Rakotomalata, P Sierwald & BL Fisher. 2005. Convergent evolution of chemical defense in poison frogs and arthropod prey between Madagascar and the Neotropics. Proceedings of the National Academy of Sciences, 102(33): 11617-11622.

Sierwald, P & AJ Reft. 2004. The millipede collections of the world. Fieldiana, Zoology, New Series No 103, 1532: 1-100

Bueno-Villegas, J., P. Sierwald & J. E. Bond. 2004. Diplopoda. In: Bousquets, J. L., J. J. Morrone, O.Y. Ordóñes & I.V. Fernández (eds), Biodiversidad, taxonomia y biogeografia de artrópodos de México, IV: 569-599.

Bond, J.E., D. A. Beamer, M.C. Hedin  & P. Sierwald. 2003. Gradual evolution of male genitalia in a sibling species complex of millipedes. Invertebrate Systematics, 17: 711-717.

Bond, J.E., P. Sierwald. 2003. Molecular taxonomy of the Anadenobolus excisus (Diplopoda: Spirobolida: Rhinocricidae) species-group on the Caribbean island of Jamaica. Invertebrate Systematics, 17: 515-528.

Marek, P.E., J.E. Bond, and P. Sierwald. 2003. Rhinocricidae Systematics II: A species catalog of the Rhinocricidae (Diplopoda: Spirobolida) with synonymies. Zootaxa, 308: 1-108.

Sierwald P., W.A. Shear, R.M. Shelley & J.E. Bond. 2003. Millipede phylogeny revisited in the light of the enigmatic order Siphoniulida. Journal of Zoological Systematics and Evolutionary Research, 41(2): 87-99.

Bond, J.E. & P. Sierwald. 2002. Eurhinocricus rosenbergi, a new species of rhinocricid from the Caribbean island of Jamaica  (Spirobolida: Rhinocricidae). The Proceedings of the Biological Society of  Washington, 115(3): 670-675.

Bond, J.E. & P. Sierwald. 2002. Cryptic speciation in the Anadenobolus excisus millipede species complex on the island of Jamaica. Evolution, 56(6): 1123-1135.

Sierwald, P. & S. I. Golovatch. 2001. Review of the genus Poratia (Diplopoda, Polydesmida, Pyrgodesmidae). Arthropoda Selecta, 9(3): 181-192.

Shelley, R, P Sierwald, SB Kiser & SI Golovatch. 2000. Nomenclator generum et familiarum Diplopodorum II. A list of the Genus and Family-group names in the Class Diplopoda from 1958 through 1999. Pensoft Publisher, Bulgaria, 167pp.

Airame, S & P. Sierwald. 2000. Hunting and feeding behavior of one Heteropoda species in lowland rainforest on Borneo (Araneae: Sparassidae). Journal of Arachnology, 28(2): 251-253.

Sierwald, P. 2000. Description of the male of Sosippus placidus, with notes on the subfamily Sosippinae (Araneae, Lycosidae). Journal of Arachnology, 28(2): 133-141.

Sierwald, P. & T. Fenzl. 1999. Argyrodes in webs of the Floridian red widow spider (Araneae: Theridiidae). Florida Entomologist, 82(2): 359-361.

Sierwald, P. 1997. Phylogenetic analysis of pisaurine nursery web spiders, with revisions of Tetragonophthalma  and Perenethis) (Araneae: Lycosoidea: Pisauridae). Journal of Arachnology, 25: 361-407, 101 figs.

Goodman, S. M., P.P. Parrillo, S. James & P.  Sierwald. 1996. Elevational variation in soil macrofauna invertebrates on the eastern slopes of the Réserve Naturelle Intégrale d'Andringintra, Madagascar. Fieldiana, (NS) 85: 144-152.

Sierwald, P. 1993. Revision of the spider genus Paradossenus, with notes on the family Trechaleidae and the subfamily Rhoicininae (Araneae: Lycosoidea). Review Arachnologique, 10(3): 53-74.

Sierwald, P. 1990. Morphology and homologous features in the male palpal organs in spiders, with special reference to Pisauridae (Arachnida: Araneae). Nemouria, 35; 1-70, 51 figs.

Sierwald, P. 1989. Notes on the behavior of Thalassius spinosissimus.  Psyche, 95(2): 243 - 252, 5 figs.

Sierwald, P. 1989. Morphology and ontogeny of female copulatory organs in American Pisauridae, with special reference to homologous features.  Smithsonian Contributions to Zoology, 462: 1-24, 62 figs.

Sierwald, P. 1988. Spiders of Bermuda. Nemouria, 31: 24pp, 5 figs.

Sierwald, P. 1988. with J.A. Coddington.  Functional aspects of the male palpal organ in Dolomedes tenebrosus, with notes on the mating behavior (Araneae, Pisauridae).  Journal of Arachnology, 16: 262 - 265, 2 figs.

Sierwald, P. 1987. Revision der Gattung Thalassius (Arachnida: Araneae: Pisauridae).  Verhandlungen des naturwissenschaftlichen Vereins zu Hamburg, (NF) 29: 51 - 142, 148 figs.

Sierwald, P. 1984. Madagassische Arten der Gattung Thalassius Simon, 1885. (Arachnida: Araneae: Pisauridae). Verhandlungen des naturwissenschaftlichen Vereins zu Hamburg, (NF) 27: 405-416, 6 figs.

Sierwald, P. 1983. Morphological criteria and the discrimination of species of the genus Thalassius Simon, 1885 (Arachnida: Araneae: Pisauridae). Verhandlungen des naturwissenschaftlichen Vereins zu Hamburg, (NF) 26: 201-209, 6 figs.


Other publications

Sierwald, P. & R. Bieler (eds). 2005. NSF-DFG-Conference Program and Abstracts.

Sierwald P., R. Bieler, J. Hanken, & R. Magill. 2002. NEON-V: CRIPTON Workshop: Collections, Research, Inventories, and People for Taxonomic Opportunities in NEON. Final Report. On-line available at:

Bueno-Villegas, J., P. Sierwald, & A. Espinosa. 2002. Filogenia y biogeographía del género Sphaeriodesmus Peters, 1864  (Diplopoda: Polydesmida: Sphaeriodesmidae). I. Ubicación del género en la familia y caracteres morfológicos que lo definen. (Poster)

Sierwald, P. 1988. Australian Spiders. Book review. American Arachnology, 38: 3.

Sierwald, P. 1990. Note on a technique for cleaning female copulatory organs in spiders. American Arachnology, 41: 2.

Sierwald, P. 1998. (ed.) (with Norman Platnick & Marius van der Merwe). Abstracts, XIV International Congress of Arachnology. 45 pp.

Sierwald, P. and C. Maier. 1992. Amazing Spiders. Educator’s Guide. Delaware Museum of Natural History, Greenville, Delaware, 86 pp.

Sierwald, P. 1994. Educator’s Guide. Smithsonian Traveling Exhibit Service.


On-line Publications:

Sierwald, P. 2007: Milli-PEET, URL:

Sierwald, P. (ed.). 2007. On-line publication of the Nomenclator I and II (comprehensive generic and family-group name listing with type species and complete bibliography). URL