Myrmecicultoridae, a New Family of Myrmecophilic Spiders from the Chihuahuan Desert (Araneae: Entelegynae)

Abstract

The new genus and species Myrmecicultor chihuahuensis Ramirez, Grismado, and Ubick is described and proposed as the type of the new family, Myrmecicultoridae Ramirez, Grismado, and Ubick. The species is ecribellate, with entelegyne genitalia, two tarsal claws, without claw tufts, and the males have a retrolateral palpal tibial apophysis. Some morphological characters suggest a pos¬ sible relationship with Zodariidae or Prodidomidae, but the phylogenetic analysis of six markers from the mitochondrial (12S rDNA, 16S rDNA, cytochrome oxidase subunit I) and nuclear (histone H3, 18S rDNA, 28S rDNA) genomes indicate that M. chihuahuensis is a separate lineage emerging near the base of the Dionycha and the Oval Calamistrum clade. The same result is obtained when the molecular data are combined with a dataset of morphological characters. Specimens of M. chi¬ huahuensis were found associated with three species of harvester ants, Pogonomyrmex rugosus, Novomessor albisetosis, and Novomessor cockerelli, and were collected in pitfall traps when the ants are most active. The known distribution spans the Big Bend region of Texas (Presidio, Brewster, and Hudspeth counties), to Coahuila (Cuatro Cienegas) and Aguascalientes (Tepezala), Mexico.

Converging on the orb: denser taxon sampling elucidates spider phylogeny and new analytical methods support repeated evolution of the orb web

“…Over the course of several hundred million years, spiders have evolved into myriad shapes and sizes, filling niches in virtually all terrestrial (and some aquatic) habitats, except in Antarctica. Currently, over 48 000 species are described among 128 families (World Spider Catalog, 2020), with sixfamilies described in the last two years (Hedin et al, 2019; Ramírez et al, 2019; Opatova et al, 2020). One of the most iconic traits of spiders is the production of silk, along with its many uses.…”

A completely resolved phylogenetic tree of British spiders

“…The deep phylogenetic relationships of spider families have recently been addressed by a series of molecular genetic studies (Agnarsson et al 2013; Bond et al 2014; Dimitrov et al 2017; Fernandez et al 2014, 2018; Garrison et al 2016; Opatova et al 2020; Ramírez 2014; Ramírez et al 2019, 2021; Shao & Li 2018; Wheeler et al 2017). These show considerable agreement with previous morphological analyses (e.g., the trees shown in Coddington 2005 or Jocqué & Dippenaar-Schoeman 2006), and where they disagree (e.g., regarding the non-monophyly of orb-web weavers or the placement of Mimetidae among Araneoidea), the strong statistical support for the alternative hypotheses and the agreement of independent molecular analyses indicate that the latter recover the true evolutionary relationships.…”

“…Molecular studies, as well as classical morphological work and integrative “whole-evidence” analyses, are covering large parts of spider diversity with increasing density. The last years have seen the publication of several comprehensive phylogenetic studies of the entire order, based on continuously increasing species coverage and ever-larger amounts of (mostly molecular) data (e.g., Agnarsson et al 2013; Bond et al 2014; Dimitrov et al 2017; Fernandez et al 2014, 2018; Garrison et al 2016; Hedin et al 2019; Kulkarni et al 2020; Opatova et al 2020; Ramírez 2014; Ramírez et al 2019, 2021; Shao & Li 2018; Wheeler et al 2017). Subsets of the order, from superfamilies to individual groups of genera, have also been the target of various analyses (e.g., Crews et al 2020; Godwin et al 2018; Hedin et al 2018; Kallal et al 2020; and numerous publications cited below for individual families).…”

The Lepidoptera of Cuatrociénegas Protected Area 1. A new species in the genus Callistege Hübner, [1823] (Erebidae, Erebinae, Euclidiini) from the Chihuahuan Desert, Coahuila, Mexico

“…The MSBA arthropod inventory study discovered 22 new species of terrestrial arthropods at Cuatrociénegas, including; three grasshoppers ( Orthoptera ), three katydids ( Orthoptera ), three crickets ( Orthoptera ), one cockroach ( Blattodea : Corydiidae ; Arenivaga gumperza , Hopkins 2014 ), six other beetles ( Coleoptera ), two moths ( Lepidoptera ) and one spider ( Araneae ) ( Lightfoot et al 2017 ). Additionally, two of the new species at Cuatrociénegas also represent one new genus of katydid, and one new family of spider, which was recently described ( Araneae : Myrmecicultoridae : Entelygynae: Myrmecicultor chihuahuensis ; Ramirez et al 2019 ). Two of the other six new species of beetles found in the UNM inventory survey include three darkling beetles ( Tenebrionidae ), two that were recently described ( Smith et al 2011 , Wirth and Smith 2017 ), two species of scarab beetles described by Smith and Paulson (2017), and three new species of elaterid click beetles that were recently described ( Johnson and Lightfoot 2018 ).…”