Horned and spiky: Tegotettix derijei sp. n. (Orthoptera: Tetrigidae) is a peculiar new pygmy grasshopper species from Mindanao Author Patano, Romeo R. 0000-0001-5020-6048 Center for Biodiversity Research and Extension in Mindanao, Central Mindanao University, Musuan, Maramag, Bukidnon 8710, Philippines. & Department of Biology, College of Arts and Sciences, Central Mindanao University, 8710, Musuan Bukidnon, Philippines. romeonojrpatano @ gmail. com; https: // orcid. org / 0000 - 0001 - 5020 - 6048 romeonojrpatano@gmail.com Author Mohagan, Alma B. 0000-0002-8303-5131 Center for Biodiversity Research and Extension in Mindanao, Central Mindanao University, Musuan, Maramag, Bukidnon 8710, Philippines. & Department of Biology, College of Arts and Sciences, Central Mindanao University, 8710, Musuan Bukidnon, Philippines. romeonojrpatano @ gmail. com; https: // orcid. org / 0000 - 0001 - 5020 - 6048 romeonojrpatano@gmail.com Author Tumbrinck, Josef 0000-0001-8865-5551 Auf der Hees, Wassenberg, D- 41849 Germany. Author Amoroso, Victor B. 0000-0002-8955-7934 Center for Biodiversity Research and Extension in Mindanao, Central Mindanao University, Musuan, Maramag, Bukidnon 8710, Philippines. & Department of Biology, College of Arts and Sciences, Central Mindanao University, 8710, Musuan Bukidnon, Philippines. romeonojrpatano @ gmail. com; https: // orcid. org / 0000 - 0001 - 5020 - 6048 romeonojrpatano@gmail.com Author Skejo, Josip 0000-0002-2554-4499 University of Zagreb, Faculty of Science, Department of Biology, Evolution Lab, Rooseveltov trg 6, HR. 10000 Zagreb. * corresponding author: skejo. josip @ gmail. com; https: // orcid. org / 0000 - 0002 - 2554 - 4499 skejo.josip@gmail.com text Zootaxa 2021 2021-02-19 4933 2 198 210 journal article 275742 10.11646/zootaxa.4933.2.2 c793b397-abf5-4129-96d2-c335fe222b4e 1175-5326 10081186 3999E2EF-32AF-4F6D-9BED-4A0DCE8B69D4 Tegotettix armatus species group Diagnosis . Fastigial horns high and spiky. Lateral ocelli placed at the same level as the lower margins of the compound eyes. In frontal view, frontal costa long and distinct, almost as long as half of the compound eye height. Facial carinae after the bifurcation divergent and with a concavity in the upper third. Prozona developed. Shoulders (humeral part of the pronotum) robust. Pronotum with projections on the median carina, on the discus, and on the lateral carinae. Femora armed with teeth. Chitinous surfaces very rough and tuberculated. This group of species represents the core species group of the genus Tegotettix . Composition and distribution . This species group includes Tegotettix armatus Hancock, 1913 (Borneo) , T. bufocrocodil ( Storozhenko et Dawwrueng, 2015 ) ( Thailand , Vietnam , Cambodia ), T. celebensis Günther, 1937 ( Indonesia : Sulawesi ), and T. siebersi Günther, 1938 (Borneo) ( Figure 4 ).