The family Rivetinidae includes nine confirmed genera, which are predominantly distributed in the Mediterranean Basin and across large parts of Western and Central Asia. Of these, three rivetinid genera—Microthespis Werner, 1908, Bolivaria Stål, 1877, and Rivetina Berland & Chopard, 1922—occur on the Persian Plateau. The latter two genera share several morphological similarities and occur sympatrically in parts of their distribution ranges (Kolnegari 2022). The genus Bolivaria comprises only a few confirmed species (at least three), distributed from southeastern Europe (e.g., the island of Crete, Greece) to large parts of Western and Central Asia, reaching as far east as Mongolia (Ehrmann 2002). In contrast, the genus Rivetina comprises more than 30 described species, distributed from southern Europe (e.g., the Iberian Peninsula) and northwestern Africa to Central Asia, including Pakistan and Tajikistan (Ehrmann 2002, Caesar et al. 2015, Sánchez-Vialas et al. 2015).

The Middle East and Central Asia can be regarded as major centers of diversity for Rivetina (Kaltenbach 1982, La Greca and Lombardo 1982, Kolnegari 2022). The distribution of these ground-dwelling mantids is often restricted to xerothermic environments. Most species exhibit distinct morphological and behavioral adaptations to these habitats, including uniform brown or pale coloration (never green), rapid ground running, the ability to shelter beneath stones, and oviposition in soil, notably facilitated by a pair of spines on the seventh abdominal sternite (Wieland 2013, Schwarz and Roy 2019, Kolnegari 2022).

According to previous literature, eight Rivetina species and subspecies have been identified in Iran (Beier 1968, Ehrmann 2002, Kolnegari 2023), including Rivetina caucasica caucasica (Saussure, 1871), Rivetina dolichoptera (Schulthess-Rechberg, 1894), Rivetina excellens Beier, 1956, Rivetina inermis inermis (Uvarov, 1922), Rivetina inermis iranica La Greca & Lombardo, 1982, Rivetina rhombicollis La Greca & Lombardo, 1982, Rivetina syriaca syriaca (Saussure, 1869), and Rivetina baetica baetica (Rambur, 1839). However, the presence of the latter species in Iran is considered doubtful due to the substantial geographic separation between the confirmed distribution range of the species and Iran (Kolnegari 2023).

Our recent field survey in Lorestan Province, Western Iran, led to the discovery of several Rivetinid mantids (Fig. 1). The collected specimens were reared under laboratory conditions until reaching adulthood (Fig. 2). Based on available sources, such as published papers, verified images of types (and non-types) (Svenson 2017), and examination of their morphology, the specimens are assigned to Rivetina Berland & Chopard, 1922, while exhibiting some characteristics that distinguish them from their Middle Eastern congenerics. Therefore, we herein describe a new species based on detailed external morphology and male genital structures, accompanied by high-resolution photographs.

Descriptive conventions.—This section provides a concise diagnosis and morphological description of the species. To describe morphological characteristics, we followed Brannoch et al. (2017), except for the following: head length includes the labrum, foretibia length includes the apical claw, and total length was measured from the vertex of the head to the tip of the abdomen. Genitalia preparation and terminology follow Schwarz and Roy (2019). All measurements were obtained using a SaIran stereomicroscope and are presented in millimeters.

Imaging.—Habitus photographs were taken using a Nikon D850 DSLR camera equipped with a Nikon 105 mm macro lens and an SB-700 Speedlight flash. Images were processed in Adobe Photoshop CS6 Extended to improve clarity by adjusting contrast, brightness, and sharpness, and to add scale bars. Minor corrections were made using the stamp tool to remove background artifacts and distracting debris.

Depositories.—NMNHGR—National Museum of Natural History and Genetic Resources, Tehran. ETHZ—Eidgenössische Technische Hochschule Zürich. PCEH—Private Collection of Elias Handal. PCMK—Private Collection of Mahmood Kolnegari.

Material examined.—(in addition to the material of the new species) YEMEN • ♂ holotype of Rivetina dolichoptera; Hiswah near Aden; August 1891; Prince Ruspoli and Prof. Dr. Keller leg.; La Greca det.; ETHZ. IRAN • 1♂; non-type specimen of Rivetina excellens; Delvar; 4 July 2022; A. Nourozi leg.; M. Kolnegari det.; NMNHGR • 4♂; non-type specimens of Rivetina inermis iranica; Arak; 11 June 2019; M. Kolnegari det.; NMNHGR • 1♂, 1♀; non-type specimens of Rivetina rhombicollis; Jiroft; 19 August 2022; M. Kolnegari det.; NMNHGR • 1♂, 1♀; non-type specimens of Rivetina syriaca; Bushehr; 8 July 2022; H. Parvizi leg; M. Kolnegari det. ­NMNHGR. PALESTINE • 2♀; non-type specimens of Rivetina syriaca; West Bank; 11 June 2019; E. Handal leg.; PCEH.

General characteristics of the genusRivetina.—Medium- to large-sized mantids with stout bodies, superficially resembling species of the genus Bolivaria. Body coloration ranges from yellowish and gray-ochre to brown-ochre and dark grey. The head is approximately as long as wide. The lower frons is transverse. The vertex lacks any median process, is distinctly arched, and bears no secondary ocular tubercles. Compound eyes are globular, unarmed, and more strongly protruding than in Bolivaria. The pronotum is elongated and longer than the forecoxa, with a well-developed, oval supracoxal dilatation. Its lateral margins may be toothed or smooth, and the disc is usually distinctly granulated. The metazone is at most weakly keeled and is typically about twice as long as the prozone. In males, the flight organs are often fully developed but usually shorter than the abdomen. The forewings are subopaque and bear an enlarged dark anal field, whereas the hindwings have a white, dark-edged preapical spot in the discoidal field; their anal field is more or less smoky brown. The forecoxae are often armed along the dorsal crest with several large teeth. The fore femora have divergent apical lobes, small erect setae along the posterior margin, four discoidal and four posteroventral spines, with the areas between the latter denticulated; the claw groove is located proximally. The walking legs lack lobes and bear a slender genicular spur as well as two rows of small spines on the tibiae. The hind legs are long; their metatarsi are usually finely spined ventrally and are slightly longer than the remaining tarsomeres combined. The supra-anal plate is more or less triangular and keeled, usually longer than wide, and often extends beyond the cerci. The cerci are cylindrical. Male genitalia are characterized by a strongly sclerotized phallic complex. The right phallomere is ventrally provided with three pilose areas and a markedly elongate ventral ridge. Structures of the left complex are clearly individualized. The ventral phallomere lacks a right basal lobe, and the primary distal process (pda) is positioned on its left side. The lateral secondary distal process (sdpl) is distinct, whereas the median secondary distal process (sdpm) is reduced to a small, rounded lobe basally. The phalloid apophysis is divided into two branches: an anterior, widely separated, bird-head-like lobe bearing tubercles or setae, and a posterior branch forming a strong spine. The membranous lobe is moderately to densely pilose. The dorsal lamina of the left phallomere does not form a rounded lobe. Females resemble males but are generally more robust. The ocelli are small and not elevated, the antennae are shorter, and the pronotum is more strongly denticulated than in males. Females are brachypterous, with wings at most slightly longer than the pronotum. The forewings are opaque, and the hindwings are smoky brown with an eyespot in the distal part of the discoidal field. The subgenital plate bears two ventral spines (La Greca and Lombardo 1982, Ehrmann 2002, Wieland 2013, Schwarz et al. 2018, Schwarz and Roy 2019).

Several species of Rivetina have previously been reported from Iran and neighboring countries, particularly Iraq, including both species recorded in Iran and taxa shared between Iran and Iraq. These species are treated and compared in the dichotomous key provided below. Among the non-Iranian species occurring in Iraq but not included in the key, Rivetina syriaca mesopotamica La Greca & Lombardo, 1982 and Rivetina laticollis La Greca & Lombardo, 1982 have also been recorded. Rivetina syriaca mesopotamica can be readily separated from Rivetina archibaldisp. nov. by denticulated pronotum and length of the supra-anal plate, which in the latter is markedly reduced and does not extend beyond the cerci. Rivetina laticollis can likewise be readily distinguished from Rivetina archibaldisp. nov. by the shape of the pronotum, which is comparatively broader and subrhomboidal, resulting from a lower pronotum length/width ratio.

Comparative pronotal ratios.—Among the compared species, Rivetina caucasica caucasica and Rivetina dolichoptera show the highest pronotum length/width ratios (3.66 and 3.93, respectively), indicating a relatively slenderer pronotum. In contrast, Rivetina rhombicollis exhibits the lowest value (2.51), reflecting a distinctly broader pronotum. The metazone/prozone ratio is highest in Rivetina caucasica caucasica (2.44), whereas Rivetina inermis iranica shows the lowest ratio (1.78). Rivetina archibaldisp. nov. is characterized by an intermediate metazone/prozone ratio (2.03) but possesses the smallest metazone minimum width (1.78) among all examined species (Table 1).

The discovery of this new Rivetina species underscores the importance of fieldwork and the continued exploration of mantises in regions situated beyond the central parts of Iran. These peripheral areas, lying close to the borders of several Arab nations, have largely remained neglected in terms of taxonomic research. Expanding surveys into these understudied zones is revealing not only new taxa but also the biogeographical complexity and evolutionary potential of Iran’s peripheral ecosystems.

The finding of Rivetina archibaldisp. nov. within the forest floor habitats of the Zagros further highlights the exceptional ecological value of these ancient forests. Despite their significance, the Zagros ecosystems are increasingly threatened by traditional livestock grazing, recurrent wildfires, prolonged droughts, and unsustainable wood extraction. These mountain forests represent a cradle of biodiversity, supporting a remarkable array of both vertebrates and invertebrates (Heidari Safari Kouchi 2021). What can ultimately safeguard the Zagros Mountain forests and their diverse fauna and flora is community-based conservation, an approach grounded in local stewardship and participatory governance (Heidari Safari Kouchi 2021).

While our study primarily focused on the description and diagnosis of Rivetina archibaldisp. nov. within the context of the Iranian fauna, we acknowledge that the genus Rivetina as a whole would benefit from a comprehensive taxonomic revision. Such a revision, incorporating molecular and detailed morphological data across its entire range, would likely clarify species boundaries and phylogenetic relationships. However, our study demonstrates that the new species can be reliably distinguished from all known Iranian and Iraqi congeners based on clear external morphological characters and, where similarities are close, definitive male genitalia structures. The provided dichotomous key consolidates these diagnostic features for the Iranian species complex.