We review the taxonomy of the Neotropical species of the genus Pachycondyla. A new species (Pachycondyla beneditoi sp. n.) is described. Ponera pilosa new syn. is synonymized with P. crassinoda, based on a type male. Pachycondyla fuscoatra is redescribed and its distinctness from P. impressa is discussed. Pachycondyla harpax is still a taxonomic problem, with much morphological variation over a wide distribution. Pachycondyla impressa does not occur in Brazil; all previous records are P. fuscoatra or P. beneditoi. The gyne of P. lenkoi is described. Pachycondyla constricticeps new syn. is synonymized with P. striata. A neotype for P. fuscoatra is designated and lectotypes for P. harpax, P. impressa and P. striata are designated. An identification key for the Neotropical species is presented.

The monotypic ant genus Igaponera gen. nov. is proposed to include its type species I. curiosa (Mackay & Mackay, 2010). Igaponera gen. nov. is described and phylogenetically compared with other ponerine genera based on external morphology. The type species is known from a single gyne originally described in the genus Pachycondyla Smith, 1858. Igaponera curiosa is easily diagnosed by: costate sculpture on head, mesosoma, and petiole; short, robust, triangular mandibles with blunt apex; relatively large eyes set at mid-length on sides of head; lack of stridulitrum; and presence of distinct but relatively small arolia. Putative apomorphies of the new genus are: cuticular flange concealing metapleural gland opening; vertically standing hypostomal tooth with recessed base; stout mandibular shape with blunt apex; absence of stout spine-like setae on meso- and metatibial apices. Our phylogenetic results based on morphology suggest that Neoponera Emery, 1901 and Pachycondyla are the closest lineages to Igaponera, which shows intermediate characteristics as compared to those genera. The genus is apparently arboreal, known only from a seasonally flooded Igapó forest near Manaus, Brazil. Despite the collection site being frequented by researchers, no other specimens of this genus have been collected in over 40 years prior to this study.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.

We describe, Gnamptogenys rugimala n.sp, a very distinct new species of the ectatommine genus Gnamptogenys from specimens collected in forests of southeastern Brazil. We provide some data about G. rugimala n. sp occurrence and ecology as well as a species identification key for the mordax subgroup.