Based on specimens collected in southern Cambodia and western Thailand, Cryptocephalomorpha thom sp. nov., a new species of the genus Cryptocephalomorpha Ritsema, 1875 (Coleoptera, Carabidae, Pseudomorphini), is described. This study provides the first confirmed Cambodian record of the tribe and documents the occurrence of the new species in Cambodia and Thailand. A key to the Oriental genera of Pseudomorphini and an updated key to the Oriental species of the genus are provided, together with a description and illustrations of the new species.

Key Words: Cambodia, Carabidae, Cryptocephalomorpha, new species, Pseudomorphini, Thailand

Etymology: The new species is named after the Khmer word thom, meaning “large” or “big” (Khmer: ធំ). The epithet is treated as a noun in apposition and refers to the comparatively large size of the species within the genus.

The collar-door wishbone spiders of the genus Kwonkan Main, 1983 are an Australian-endemic lineage of mygalomorph spiders that often construct elaborate burrow entrances, including collars and turrets, and remain poorly documented across their range, despite museum collections indicating high local endemism and substantial undescribed diversity. Much of the existing taxonomy, including nine of the 14 currently described species, was based on limited material and lacked modern morphological or molecular approaches to species delimitation, hindering efforts to document the remaining diversity and address conservation concerns. Here, we redescribe all nine legacy species and review Kwonkan diversity within the south-western Western Australian (SWWA) agricultural region, a highly fragmented and mostly cleared landscape harbouring extensive undescribed diversity and the threatened species K. eboracum Main, 1983. In the process, we clarify species identities, present the first molecular data for several species including K. eboracum, and describe two new species (K. elatus sp. nov. and K. yorkrakine sp. nov.) that were previously attributed to legacy species. In our review of the SWWA agricultural region fauna we identify 29 putative undescribed species and a pattern of extensive sympatry, fine-scale species turnover, and extremely restricted ranges. These findings highlight the need for continued revisionary work and potential conservation listing of additional described species such as K. wonganensis (Main, 1977).

Keywords: short-range endemism, conservation systematics, mygalomorph spiders, south-western Australian biodiversity hotspot, Wheatbelt

 Jeremy D. Wilson, Arianna Urso, Michael G. Rix, Erich S. Volschenk, Valentina Cruz Bedón and Mark S. Harvey. 2026. Wishbone Spiders of the Genus Kwonkan Main, 1983 (Araneae: Mygalomorphae: Anamidae) in south-western Australia: Redescription of legacy species, Two New Species, and an assessment of agricultural zone diversity. Arthropod Systematics & Phylogeny. 84: 510-547.  DOI: doi.org/10.3897/asp.84.e189518 [08-07-2026]

 

Tarjadia ruthae is a quadrupedal terrestrial pseudosuchian from the Middle-early Upper Triassic of the Chañares Formation, La Rioja Province, Argentina. Originally, this species was identified as an indeterminate archosaur and later as a doswelliid archosauriform based on very fragmentary specimens characterized by the ornamentation of the skull roof and osteoderms. Additional specimens (including skulls and postcrania) recovered in the last decade show that Tarjadia is an erpetosuchid, an enigmatic pseudosuchian group composed of six species registered in Middle-Upper Triassic continental units of Tanzania, Germany, Scotland, North America, Brazil, and Argentina. Tarjadia ruthae from Argentina and Parringtonia gracilis from Tanzania are the best preserved and more abundant species. Although the monophyly of Erpetosuchidae is well supported, alternative high-level positions within Archosauria have been suggested, such as sister taxon to Crocodylomorpha, Aetosauria, or Ornithosuchidae. In order to improve the knowledge about the erpetosuchids, we performed a detailed description and paleoneurological reconstruction of the skull of Tarjadia ruthae, based on two articulated partial skulls (CRILAR-Pv 478 and CRILAR-Pv 495) and other fragmentary specimens. We analyzed the stratigraphic and geographic occurrence of historical and new specimens of Tarjadia and provided a new emended diagnosis (the same for the genus as for the species, due to monotypy) along with a comparative description of the cranial endocast. The skull of Tarjadia is robust, with a thick and strongly ornamented skull roof, triangular in dorsal view, with concave lateral margins at mid-length that form an abrupt widened posterior region. The external nares are the smallest openings of the skull. The antorbital fossa is deeply excavated and has a small heart-shaped fenestra with both lobes pointing anteriorly. The supratemporal fenestrae are as large and rounded as the orbits, and the infratemporal fenestrae are L-shaped with an extensive excavation along the jugal, quadratojugal and quadrate. The hemimandibles are low, slightly concave on the dentigerous region and strongly convex on the posterior region, conferring them a S-shaped profile in dorsal view. The external mandibular fenestra is small and elliptic, being twice longer than high. The maxillary dentition is restricted to the anterior to mid region of the rostrum. Since the braincase of both specimens is partially damaged, the dorsal surface of the brain could not be entirely reconstructed. As a result, the endocast is anteroposteriorly elongated and seemingly flat, and the cephalic flexure seems to be lower than expected for a suchian. The labyrinth is twice wider than high, the semicircular canals are remarkably straight, and the anterior canal is longer than the posterior one.

Archosauriformes Gauthier et al., 1988.

Archosauria Cope, 1869 sensu Gauthier & Padian, 1985.

Pseudosuchia von Zittel, 1887–1890 sensu Gauthier & Padian, 1985.

Erpetosuchidae Watson, 1917 sensu Nesbitt & Butler, 2013.

Tarjadia ruthae Arcucci & Marsicano, 1998