Skip to main content Skip to main navigation menu Skip to site footer
Type: Article
Published: 2022-06-21
Page range: 151-186
Abstract views: 639
PDF downloaded: 30

On the Tityus forcipula species group: redescription of Tityus forcipula (Scorpiones, Buthidae), description of a new Andean species, and notes on the taxonomy of the group

Instituto de Biociências – Universidade de São Paulo, Departamento de Zoologia. Rua do Matão, travessa 14, 321, 005508-900, São Paulo, SP, Brazil
Instituto de Biociências – Universidade de São Paulo, Departamento de Zoologia. Rua do Matão, travessa 14, 321, 005508-900, São Paulo, SP, Brazil
Departamento de Biología, Universidad del Valle, Ciudad Universitaria Meléndez, Calle 13 # 100-00, 760032, Cali, Colombia.
Scorpiones taxonomy poisonous species Neotropical region scorpion new species


The Tityus forcipula species group has had an intricate taxonomic history, changing its diagnostic characters and composition on several occasions. One of the alleged reasons for this taxonomic uncertainty is the use of superficial characters (i.e. raw similarity instead of putative synapomorphies) for species group delimitation. Here, we conducted a thorough phenotypic survey across the Tityus forcipula species group, as currently delimited, including characters that had been suggested elsewhere as putative synapomorphies for delimiting lineages within Tityus. In doing so we also redescribe Tityus forcipula and describe a new species belonging to the Tityus forcipula species group: Tityus moralensis sp. nov. based on specimens from the Andean region of Valle del Cauca department, Colombia. The Tityus forcipula species group is here delimited to Andean species from Colombia and Ecuador that share strongly sclerotized and brown colored pectines, basal middle lamellae of female pectines dilated and suboval or ovoid shaped, basal plate of female pectines without glandular region and telotarsi with two ventrosubmedian rows (type II) of stout macrosetae (i.e., Tityus crassicauda, Tityus cuellari, Tityus forcipula, Tityus fuhrmanni and Tityus moralensis sp. nov). The new Tityus species is placed into a phylogenetic context with other buthid species using DNA sequences (COI and 28S). Finally, we provide a map with updated distributional records of the Tityus forcipula species group.



  1. Arbeláez-Cortés, E. (2013) Knowledge of Colombian biodiversity: published and indexed. Biodiversity and Conservation, 22 (12), 2875–2906.
    Armas, L.F. de (2020) Scorpions of Puerto Rico and its satellite islands (Scorpiones: Buthidae, Diplocentridae): an аnnotated list, key for genera, and bibliography. Euscorpius, 311, 1–10.
    Armas, L.F. de, Víquez, C. & Montoya, M. (2002) Complementos a la descripción de Tityus dedoslargos (Scorpiones: Buthidae). Revista de Biología Tropical, 50, 161–167.
    Astrin, J.J., Höfer, H., Spelda, J., Holstein, J., Bayer, S., Hendrich, L., Bayer, S., Hendrich, L., Huber, B.A., Kielhorn, K.H., Krammer, H.J., Lemke, M., Monje, J.C., Morinière, J., Rulik, B., Petersen, M., Janssen, H. & Muster, C. (2016) Towards a DNA Barcode Reference Database for spiders and harvestmen of Germany. PloS ONE, 11, e0162624.
    Azevedo, G.H., Bougie, T., Carboni, M., Hedin, M. & Ramírez, M.J. (2022). Combining genomic, phenotypic and Sanger sequencing data to elucidate the phylogeny of the two-clawed spiders (Dionycha). Molecular Phylogenetics and Evolution, 166, 107327.
    Borges, A., Bermingham, E., Herrera, N., Alfonzo, M.J. & Sanjur, O.I. (2010) Molecular systematics of the neotropical scorpion genus Tityus (Buthidae): The historical biogeography and venom antigenic diversity of toxic Venezuelan species. Toxicon, 55, 436–454.
    Borges, A., Lomonte, B., Angulo, Y., Acosta de Patino, H., Pascale, J.M., Otero, R., Miranda, R.J., de Sousa, L., Grahan, M.R., Gómez, A., Pardal, P.P.O., Ishikawa, E., Bonilla, F., Castillo, A., de Ávila, R.A.M., Gómez, J.P. & Caro-López, J.A. (2020) Venom diversity in the neotropical scorpion genus Tityus: implications for antivenom design emerging from molecular and immunochemical analyses across endemic areas of scorpionism. Acta Tropica, 204, 105346.
    Botero-Trujillo, R. & Fagua, G. (2007) Additions to the knowledge of the geographical distribution of some Colombian scorpions (Buthidae: Ananteris, Rhopalurus, Tityus). Revista Ibérica de Aracnología, 14, 129–134.
    Brito, G. & Borges, A. (2015) A checklist of the scorpions of Ecuador (Arachnida: Scorpiones), with notes on the distribution and medical significance of some species. Journal of Venomous Animals and Toxins Including Tropical Diseases, 21, 1–17.
    Dupré, G. (2021) Checklist of scorpions’ taxa 1758-2020. Arachnides, 100, 2–111.
    Esposito, L.A., Yamaguti, H.Y., Souza, C.A., Pinto-da-Rocha, R. & Prendini, L. (2017) Systematic revision of the neotropical club-tailed scorpions, Physoctonus, Rhopalurus, and Troglorhopalurus, revalidation of Heteroctenus, and descriptions of two new genera and three New Species (Buthidae: Rhopalurusinae). Bulletin of the American Museum of Natural History, 415, 1–136.
    Esposito, L.A., Yamaguti, H.Y., Pinto-da-Rocha, R. & Prendini, L. (2018) Plucking with the plectrum: Phylogeny of the New World buthid scorpion subfamily Centruroidinae Kraus, 1955 (Scorpiones: Buthidae) reveals evolution of three pecten-sternite stridulation organs. Arthropod Systematics and Phylogeny, 76, 87–122.
    Ewing, B. & Green, P. (1998) Base-calling of automated sequencer traces using phred. II. Error probabilities. Genome research, 8 (3), 186–194.
    Ewing, B., Hillier, L., Wendl, M.C. & Green, P. (1998) Base-calling of automated sequencer traces usingPhred. I. Accuracy assessment. Genome research, 8 (3), 175–185.
    Fet, V. & Lowe, G. (2000) Family Buthidae C. L. Koch, 1837. In: Catalog of the Scorpions of the World. The New York Entomological Society, New York, New York, pp. 54–286.
    Flórez, D.E. (2001) Escorpiones de la familia Buthidae (Chelicerata: Scorpiones) de Colombia. Biota Colombiana, 2, 25–30.
    Flórez, D.E. (2011) Escorpiones en el Chocó Biogeográfico. In: Colombia Diversidad Biótica IV. El Chocó biogeográfico/Costa pacifica. Universidad Nacional de Colombia, Bogotá D.C., Colombia, Bogotá, pp. 763–767.
    Flórez, D.E. (2015) Orden Scorpiones. In: Los artrópodos de la reserva natural río Ñambí. Serie de guías de campo del Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Instituto de Ciencias Naturales, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, pp. 81–88.
    Francke, O.F. (1977) Scorpions of the genus Diplocentrus from Oaxaca, Mexico (Scorpionida, Diplocentridae). Journal of Arachnology, 4, 145–200.
    Francke, O.F. (2019) Conspectus Genericus Scorpionorum 1758–1985 (Arachnida: Scorpiones) updated through 2018. Zootaxa, 4657 (1), 1–56.
    Gervais, P.M. (1843) Les principaux résultats d’un travail sur la famille des Scorpions. Société Philomatique de Paris 5, 129–131.
    Goloboff, P.A. & Catalano, S.A. (2016) TNT version 1.5, including a full implementation of phylogenetic morphometrics. Cladistics, 32 (3), 221–238.
    Gómez, J.P., Velásquez, P., Díaz, A., Saldarriaga, M. & Otero, R. (2002) Aspectos biológicos y ecológicos del escorpión Tityus fuhrmanni (Kraepelin, 1914), en poblaciones del cerro El Volador y barrios aledaños de la ciudad de Medellín. Actualidades Biológicas, 24, 103–111.
    González-Sponga, M.A. (2011) Escorpiones, características, distribución geográfica y comentarios generales. In: Emergencia por animales ponzoñosos en las Américas. Instituto Bioclon, SA de CV, México, D.F., pp. 65–114.
    Gordon, D., Abajian, C. & Green, P. (1998) Consed: A graphical tool for sequence finishing. Genome research, 8 (3), 195–202.
    Gordon, D., Desmarais, C. & Green, P. (2001) Automated finishing with autofinish. Genome research, 11 (4), 614–625.
    Guindon, S., Dufayard, J-F., Lefort, V., Anisimova, M., Hordijk, W. & Gascuel, O. (2010) New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Systematic Biology, 59 (3), 307–321.
    Hedin, M.C. & Maddison, W.P. (2001) A combined molecular approach to phylogeny of the jumping spider subfamily Dendryphantinae (Araneae: Salticidae). Molecular Phylogenetics and Evolution, 18, 386–403.
    Hoang, D.T., Chernomor, O., von Haeseler, A., Minh, B.Q. & Vinh, L.S. (2018) UFBoot2: improving the ultrafast bootstrap approximation. Molecular Biology and Evolution, 35 (2), 518–522.
    Hortal, J., de Bello, F., Diniz-Filho, J.A.F., Lewinsohn, T.M., Lobo, J.M. & Ladle, R.J. (2015) Seven shortfalls that beset large-scale knowledge of biodiversity. Annual Review of Ecology, Evolution, and Systematics, 46, 523–549.
    Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K., von Haeseler, A. & Jermiin, L.S. (2017) ModelFinder: fast model selection for accurate phylogenetic estimates. Nature Methods, 14 (6), 587–589.
    Katoh, K. & Standley, D.M. (2013) MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution, 30 (4), 772–80.
    Koch, C.L. (1836) s.n. In: Die Arachniden. 3 (1–5). C. H. Zehsche Buchhandlung, Nürnberg, pp. 17–104.
    Koch, C.L. (1837) Scorpionen. In: Übersicht des Arachnidensystems. C.H. Zeh‘sche Buchhandlung, Nürnberg, pp. 36–40.
    Koch, N.M. & Thompson, J.R. (2021) A total-evidence dated phylogeny of echinoidea combining phylogenomic and paleontological data. Systematic Biology, 70 (3), 421–439.
    Kovařík, F., Teruel, R., Cozijn, M.A.C. & Seiter, M. (2013) Tityus carolinae sp. n. from Suriname and Guyana (Scorpiones: Buthidae). Euscorpius, 178, 1–9.
    Kraepelin, K. (1911) Neue Beiträge zur Systematik der Glieder- spinnen. Mitteilungen aus dem Naturhistorischen Museum 2. Beiheft zum Jahrbuch der Hamburgischen wissen- schaftlichen Anstalten, 28, 59–107.
    Kraepelin, K. (1914) Beitrag zur Kenntnis der Skorpione und Pedipalpen Columbiens. Memoires de la Société des Sciences naturelles, Neuchatel, 5, 15–28.
    Larsson, A. (2014) AliView: a fast and lightweight alignment viewer and editor for large datasets. Bioinformatics, 30 (22), 3276–3278.
    Loria, S.F. & Prendini, L. (2014) Homology of the lateral eyes of scorpiones: A six-ocellus model. PLoS ONE, 9, 1–30.
    Lourenço, W.R. (1984) Etude systématique de quelques espèces appartenant au complexe Tityus forcipula (Gervais, 1844) (Scorpiones, Buthidae). Bulletin du Muséum national d’histoire naturelle. Section A, Zoologie, biologie et écologie animales, 6, 729–739.
    Lourenço, W.R. (1988) La faune des Scorpions de l’Equateur. I. Les Buthidae. Systématique et biogéographie. Revue Suisse de Zoologie, 95, 681–697.
    Lourenço, W.R. (1994) Scorpions (Chelicerata) de Colombie. VI. Quatre nouvelles espèces de Buthidae des régions amazonienne, sud-pacifique et de la Cordillère Orientale. Revista de la Academia Colombiana de Ciencias 19, 387–392.
    Lourenço, W.R. (1997) Synopsis de la faune de scorpions de Colombie, avec des considérations sur le systématique et la biogéographie des espèces. Revue Suisse de Zoologie, 104, 61–94.
    Lourenço, W.R. (1998) A new species of Tityus C. L. Koch, 1836 (Scorpiones, Buthidae) in Colombia, with a checklist and key to the Colombian species of the genus. Zoosystema, 20, 487–497.
    Lourenço, W.R. (1999) A new species of Tityus Koch, 1836 (Chelicerata, Scorpiones, Buthidae) from Department Cesar in Colombia. Revue Arachnologique, 13, 1–6.
    Lourenço, W.R. (2000) Synopsis of the colombian species of Tityus Koch (Chelicerata, Scorpiones, Buthidae), with descriptions of three new species. Journal of Natural History, 34, 449–461.
    Lourenço, W.R. (2002a) Scorpions of Brazil. Les editions de l’If Paris, Paris, 304 pp.
    Lourenço, W.R. (2002b) Nouvelles additions à la faune de scorpions néotropicaux (Arachnida). Revue suisse de Zoologie, 109, 127–141.
    Lourenço, W.R. (2005) A new species of Tityus Koch, 1836 (Scorpiones, Buthidae) from Ecuador. Entomologische Mitteilungen aus dem Zoologischen Museum Hamburg, 14, 221–227.
    Lourenço, W.R. (2006) Une nouvelle proposition de découpage sous-générique du genre “Tityus” C. L. Koch, 1836 (Scorpiones, Buthidae). Boletín Sociedad Entomológica Aragonesa, 39, 55–67.
    Lourenço, W.R. (2007) A new species of Tityus C. L. Koch, 1836 from Ecuador: the first element of the ‘Tityus androcottoides’ subgroup for this country. Entomologische Mitteilungen aus dem Zoologischen Museum Hamburg, 176, 375–385.
    Lourenço, W.R. (2011) The distribution of noxious species of scorpions in Brazilian Amazonia: the genus Tityus C. L. Koch, 1836, subgenus Atreus Gervais, 1843 (Scorpiones, Buthidae). Journal of Venomous Animals and Toxins Including Tropical Diseases, 15, 287–301.
    Lourenço, W.R. (2016) A propos de quelques amendements sur quelques espèces du genre Tityus C. L. Koch, 1836 (Scorpiones: Buthidae) de la région amazonienne. Arachnida - Rivista Aracnologica Italiana, 2, 1–17.
    Lourenço, W.R. & Flórez, D.E. (1990) Scorpions (Chelicerata) from Colombia III. The scorpio-fauna of pacific region (Choco), with some biogeographic considerations. Amazoniana, 11, 119–133.
    Lourenço, W.R. & Leguin, E.-A. (2008) The true identity of Scorpio (Atreus) obscurus Gervais, 1843 (Scorpiones, Buthidae). Euscorpius, 2008, 1–9.
    Lourenço, W.R. & Maury, E.A. (1985) Contribution à la connaissance systématique des scorpions appartenant au «complexe» Tityus bolivianus Kraepelin, 1895 (Scorpiones, Buthidae). Revue Arachnologique, 6, 107–126.
    Lourenço, W.R. & Otero, R. (1998) Tityus antioquensis sp. n., a new species of scorpion from the Department Antioquia, Cordillera Central of Colombia (Scorpiones, Buthidae), with a checklist and key for the Colombian species of the genus. Entomologische Mitteilungen aus dem Zoologischen Museum Hamburg, 12, 298–307.
    Lourenço, W.R. & Ythier, E. (2013) The remarkable scorpion diversity in the Ecuadorian Andes and description of a new species of Tityus C. L. Koch, 1836 (Scorpiones, Buthidae). ZooKeys, 307, 1–13.
    Lourenço, W.R. & Ythier, E. (2017) Description of Tityus (Atreus) cisandinus sp. n. from Ecuadorian Amazonia, with comments on some related species (Scorpiones: Buthidae). Arachnida - Rivista Aracnologica Italiana, 15, 18–34.
    Lourenço, W.R., Leguin, E.-A. & Cloudsley-Thompson, J.L. (2009) The status of Tityus (Atreus) rufofuscus Pocock, 1897 (Scorpiones, Buthidae), an enigmatic scorpion described from Brazil. Boletín Sociedad Entomológica Aragonesa, 45, 423–427.
    Lourenço, W.R., Rossi, A. & Wilmé, L. (2019) Further clarifications on species of Tityus C. L. Koch, 1836, subgenus Atreus Gervais, 1843 (Scorpiones: Buthidae), from Amazonia, with the description of a new species. Arachnida - Rivista Aracnologica Italiana, 21, 1–24.
    Mello-Leitão, C. de (1931) Divisão e distribuição do gênero Tityus Koch. Annaes da Academia brasileira de Ciencias, 3, 119–150.
    Mello-Leitão, C. de (1939) Revisão do gênero Tityus. Physis, 17, 57–76.
    Mello-Leitão, C. de (1945) Escorpiões sul-americanos. Arquivos do Museu Nacional, 40, 7–468.
    Miranda, R.J., Bermúdez, S., Flórez, D.E. & Armas, L.F. de (2020) A new species of Tityus from Panama and Costa Rica previously identified as Tityus pachyurus Pocock, 1897 (Scorpiones: Buthidae). Revista Ibérica de Aracnología, 37, 197–204.
    Mirshamsi, O., Sari, A., Elahi, E. & Hosseinie, S. (2010). Phylogenetic relationships of Mesobuthus eupeus (CL Koch, 1839) inferred from COI sequences (Scorpiones: Buthidae). Journal of Natural History, 44 (47–48), 2851–2872.
    Mirza, Z.A. (2020) Two new species of buthid scorpion of the genus Janalychas Kovařík, 2019 (Arachnida: Scorpiones: Buthidae) from the Western Ghats, India. Arachnology, 18 (4), 316–324.
    Moreno-González, J.A., González, O.R. & Flórez, D.E. (2019). Taxonomic revision of the Colombian Tityus (Archaeotityus) (Scorpiones, Buthidae) species: a morphological and morphometric approach, with a description of a new species. Zootaxa, 4660 (1), 1–94.
    Moreno-González, J.A. & Hazzi, N.A. (2012) Intraguild predation case: Tityus forcipula Gervais, 1843 (Scorpiones, Buthidae) feeding on Chactas vanbenedeni Gervais, 1843 (Scorpiones, Chactidae) in Colombia. Revista Ibérica de Aracnología, 20, 117–120.
    Moreno-González, J.A., Pinto-da-Rocha, R. & Gallão, J. (2021) Bringing order to a complex system: novel phenotypic characters and genotypic evidence contribute to the taxonomy of Tityus and support the description of a new cave dwelling species (Scorpiones: Buthidae) from Brazil. Zookeys, 1075, 33–75.
    Neumann, J.S., Desalle, R., Narechania, A., Schierwater, B. & Tessler, M. (2021). Morphological characters can strongly influence early animal relationships inferred from phylogenomic data sets. Systematic biology, 70 (2), 360–375.
    Nguyen, L.-T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32 (1), 268–74.
    Ojanguren-Affilastro, A.A., Adilardi, R.S., Mattoni, C.I., Ramírez, M.J. & Ceccarelli, F.S. (2017) Dated phylogenetic studies of the southernmost American buthids (Scorpiones; Buthidae). Molecular Phylogenetics and Evolution, 110, 39–49.
    Paradis, E. & Schliep, K. (2019) ape 5.0: an environment for modern phylogenetics and evolutionary analyses in R. Bioinformatics, 35 (3), 526–528.
    Pocock, R.I. (1897) LIII. Descriptions of some new species of scorpions of the genus Tityus, with notes upon some forms allied to T. americanus. Journal of Natural History, 19, 510–521.
    Prendini, L. (2000) Phylogeny and Classification of the Superfamily Scorpionoidea Latreille 1802 (Chelicerata, Scorpiones): An Exemplar Approach. Cladistics, 78, 1–78.
    Prendini, L. (2003) Discovery of the male of Parabuthus muelleri, and implications for the phylogeny of Parabuthus (Scorpiones: Buthidae). American Museum Novitates, 3408, 1–24.
    Rein, J.O (2022) The Scorpion Files. Trondheim: Norwegian University of Science and Technology. Available from: (accessed 7 June 2022)
    Salazar, A., Sanchez, A., Villegas, J.C., Salazar, J.F., Ruiz Carrascal, D., Sitch, S., Restrepo, J.D., Poveda, G., Feeley, K.J., Mercado, L.M. & Arias, P.A. (2018) The ecology of peace: preparing Colombia for new political and planetary climates. Frontiers in Ecology and the Environment, 16 (9), 525–531.
    Saldarriaga, M.M. & Otero, R. (2000) Los escorpiones: aspectos ecológicos, biológicos y toxinológicos. MedUNAB, 3, 17–23.
    Sánchez-Pacheco, S.J., Torres-Carvajal, O., Aguirre-Peñafiel, V., Sales Nunes P.M., Verrastro, L., Rivas, G.A., Rodrigues, M.T., Grant, T. & Murphy, R.W. (2018) Phylogeny of Riama (Squamata: Gymnophthalmidae), impact of phenotypic evidence on molecular datasets, and the origin of the Sierra Nevada de Santa Marta endemic fauna. Cladistics, 34 (3), 260–291.
    Santiago-Blay, J.A. (1985) Redescription of Tityus dasyurus dasyurus Pocock, 1897 (Scorpiones, Buthidae). Revue Arachnologique, 6, 49–56.
    Schulmeister, S. (2003) Simultaneous analysis of basal Hymenoptera (Insecta): introducing robustchoice sensitivity analysis. Biological Journal of the Linnean Society, 79, 245–275.
    Schwendinger, P.J. & Giribet, G. (2005) The systematics of the south-east Asian genus Fangensis Rambla (Opiliones: Cyphophthalmi: Stylocellidae). Invertebrate Systematics, 19, 297–323.
    Seiter, M., Friedl, N. & Cozijn, M.A.C. (2020) Life history aspects of the buthid scorpion Tityus forcipula (Gervais, 1843) with remarks on its thermal limits. Journal of Arachnology, 48, 161–168.
    Sissom, W.D., Polis, G.A. & Watt, D.D. (1990) Field and laboratory methods. In: The Biology of Scorpions. Stanford University Press, Redwood City, California, pp. 445–461.
    Soleglad, M.E. & Fet, V. (2003) The scorpion sternum: structure and phylogeny (Scorpiones: Orthosterni). Euscorpius, 5, 1–34.
    Souza, C.A.R.D.E., Candido, D.M., Lucas, S.M. & Brescovit, A.D. (2009) On the Tityus stigmurus complex (Scorpiones, Buthidae). Zootaxa, 1987 (1), 1–38.
    Stahnke, H.L. (1970) Scorpion nomenclature and mensuration. Entomological News, 81, 297–316.
    Suranse, V., Sawant, N.S., Paripatyadar, S.V., Krutha, K., Paingankar, M.S., Padhye, A.D., Bastawade, D.B. & Dahanukar, N. (2017) First molecular phylogeny of scorpions of the family Buthidae from India. Mitochondrial DNA Part A, 28 (4), 606–611.
    Thorell, T. 1891. Nova species Brasiliana ordinis Scorpionum. Entomol tidskrift, 12 (2), 65–70.
    Teruel, R. & García, L.F. (2008) Rare or poorly known scorpions from Colombia. I. Redescription of Tityus macrochirus Pocock, 1897 (Scorpiones: Buthidae). Euscorpius, 63, 1–11.
    Vachon, M. (1963) De l’utilité, en systématique, d’une nomenclature des dents des chélicères chez les Scorpions. Bulletin du Muséum national d’Histoire naturelle, Paris, 161–166.
    Vachon, M. (1974) Etude des caractères utilisés pour classer les familles et les genres de Scorpions (Arachnides). 1. La trichobothriotaxie en arachnologie. Sigles trichobothriaux et types de trichobothriotaxie chez les Scorpions. Bulletin du Muséum national d’Histoire naturelle, Paris, 140, 857–958.
    Vachon, M. (1975) Sur l’utilisation de la trichobothriotaxie du bras des pédipalpes des Scorpions (Arachnides) dans le classe- ment des genres de la famille des Buthidae Simon. Comptes Rendus des séances de l’Académie des Sciences, Paris, Série D, 281, 1597–159.
    Whiting, M.F., Carpenter, J.C., Wheeler, Q.D. & Wheeler, W.C. (1997) The Strepsiptera problem: phylogeny of the holometabolous insect orders inferred from 18S and 28S ribosomal DNA sequences and morphology. Systematic Biology, 46, 1–68.
    Ythier, E. (2018) On the contribution of Wilson R. Lourenço to the knowledge of the scorpion fauna of Ecuador. Arachnida - Rivista Aracnologica Italiana, 17, 18–23.
    Wheeler, W.C. (2012) Systematics: A Course of Lectures. 1st Edition. Wiley-Blackwell, Oxford, 448 pp.
    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., Álvarez-Padilla, F., Arnedo, M.A., Benavides Silva, L.R., Benjamin, S.P., Bond, J.E., Grismado, C.J., Hasan, 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., Szûts, T., Ubick, D., Vink, C.J., Wood, H.M. & Zhang J. (2017) The spider tree of life: phylogeny of Araneae based on target‐gene analyses from an extensive taxon sampling. Cladistics, 33 (6), 574–616.