No recent literature is mentioned by Tobias et al 2002 (HBW 7), H&M4 ("For treatment as a subspecies of B. lugubris see Haffer (1974)" [= Avian speciation in tropical South America]), AOU-SACC or Hume & Walters 2012 ('Klages's Jacamar', after the collector).
Thanks for the references. Meyer de Schauensee treat it as synonym of B. lugubris
The subspecies phaeonota was also formerly (e.g., Todd 1943, Peters 1948) considered a separate species from Brachygalba lugubris, but was treated as conspecific by Meyer de Schauensee (1966) and subsequent classifications.
Mateus Ferreira, Alexandre M. Fernandes, Alexandre Aleixo, Alexandre Antonelli, Urban Olsson, John M. Bates, Joel Cracraft, Camila C. Ribas. Evidence for mtDNA capture in the jacamar Galbula leucogastra / chalcothorax species-complex and insights on the evolution of white-sand ecosystems in the Amazon basin. Molecular Phylogenetics and Evolution, In Press, Available online 17 July 2018.
Jacamar species occur throughout Amazonia, with most species occupying forested habitats. One species-complex, Galbula leucogastra / chalcothorax, is associated to white sand ecosystems (WSE). Previous studies of WSE bird species recovered shallow genetic structure in mtDNA coupled with signs of gene flow among WSE patches. Here, we characterize diversification of the G. leucogastra/chalcothorax species-complex with dense sampling across its distribution using mitochondrial and genomic (Ultraconserved Elements, UCEs) DNA sequences. We performed concatenated likelihood and Bayesian analysis, as well as a species-tree analysis using ∗BEAST, to establish the phylogenetic relationships among populations. The mtDNA results recovered at least six geographically-structured lineages, with G. chalcothorax embedded within lineages of G. leucogastra. In contrast, both concatenated and species-tree analyses of UCE data recovered G. chalcothorax as sister to all G. leucogastra lineages. We hypothesize that the mitochondrial genome of one of the G. leucogastra lineage (Madeira) was captured into G. chalcothorax in the past. We discuss how WSE evolution and the coevolution of mtDNA and nuclear genes might have played a role in this apparently rare event.