An integrative study of a new species of <i>Melloina</i> Brignoli: an additional support for Melloinidae new family (Araneae: Mygalomorphae)

Melloina is a genus that has long occupied an unstable taxonomic position, fluctuating between the families Paratropididae and Theraphosidae. The most recent proposal, in 2020, placed it within Theraphosidae. Alternatively, the phylogenetic relationships among Paratropididae and Theraphosidae have been controversial and subject to revision over time. Early studies suggested Paratropididae as the sister group of Theraphosidae, but recent molecular analyses have revealed that Barychelidae is more closely related to Theraphosidae than Paratropididae (Paratropis). In this study, we describe a new species, Melloina condesa sp. n., based on a morphological and multilocus approach. Phylogenetic results, using a total evidence framework, recovered Melloina as an independent lineage more closely related to Theraphosidae and Barychelidae. Based on these findings and on the comparison of diagnostic characters among the taxa under discussion, we propose a new family, Melloinidae, to include all species of Melloina.