A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates

  A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates Abstract Chelicerata is a megadiverse (over 120,000 species) arthropod clade that includes familiar taxa of profound ecological and economic importance, such as scorpions, spiders and mites 1 . Extant chelicerates share a unique anatomical character, the chelicerae—feeding first appendages terminated by a simple pincer-like chela 2 . The fossil record of these primarily predatory animals spans almost 500 million years 3 , suggesting a likely yet undocumented origin during the Cambrian Explosion. Artiopods 4 , 5 , 6 , megacheirans 4 , 7 , 8 , 9 , habeliids 10 , 11 , 12 , 13  and mollisoniids 14 , 15  have been considered Cambrian stem- or crown-group chelicerates, but they all lack unequivocal chelicerae, leaving the emergence of chelicerae-bearing arthropods unclear. Here we describe  Megachelicerax cousteaui  gen. et sp. nov., a large soft-bodied arthropod from the middle Cambrian of Ut...

A New Species of Trapdoor Spider (Araneae: Idiopidae: Heligmomerus) from the Southern Tip of India

 


A New Species of Trapdoor Spider (Araneae: Idiopidae: Heligmomerus) from the Southern Tip of India

Abstract

A new species of the genus Heligmomerus is described based on 10 female specimens collected from
the foothills of Pothaimalai, on the outskirts of the Kalakad-Mundanthurai Tiger Reserve, Tirunelveli
District, Tamil Nadu, India. The new species is distinguished from all other Indian and Sri Lankan
congeners in combination with several non-overlapping morphological characters. Detailed natural
history of the new species, intraspecific variation in spermathecal morphology, and meristic and
mensural data from the type series are given. Additionally, comments on the transfer of Idiops
garoensis (Tikader, 1977) to the genus Heligmomerus by Sen et al. (2012) are provided.

Waghe, Vivek. (2025). A NEW SPECIES OF TRAPDOOR SPIDER (ARANEAE: IDIOPIDAE: Heligmomerus) FROM THE SOUTHERN TIP OF INDIA. 10.47605/tapro.v14i1.350.