Synonymization of the genus nomen Dendroplex Swainson, 1827 and description of a new genus of woodcreeper (Aves: Passeriformes: Dendrocolaptidae) with remarks on Articles 67.5 and 70.3 of the Code.

The polytypic Straight-billed Woodcreeper Dendroplex picus (J. F. Gmelin, 1788) is one of the most complex species-groups of Dendrocolaptidae (Aves: Passeriformes), from both the nomenclatural and morphological standpoints. Firstly, its alpha taxonomy is debatable. Virtually all recent works (e.g. Aleixo 2002; Marantz et al. 2003; del Hoyo Collar 2016) have recognized just two species in the group-Dendroplex picus and Zimmer's Woodcreeper Dendroplex kienerii (Des Murs, 1856)-although some of the other described taxa possess singular morphological characters and well-defined ranges somewhat isolated from their geographically closest relatives (e.g. Plain-throated Woodcreeper Dendroplex picirostris Lafresnaye, 1847). Secondly, the correct genus to which to allocate taxa presently included in this group (vide Aleixo 2002) has been controversial. There is a considerable confusion as to which nominal species should be regarded as the type of Dendroplex Swainson, 1827b. Three species are involved in the dispute (Cory Hellmayr 1925; Peters 1951; Aleixo et al. 2002; Marantz et al. 2003; Aleixo et al. 2007): Oriolus picus J. F. Gmelin, 1788; Dendrocolaptes guttatus M. H. C. Lichtenstein, 1818; and Dendrocolaptes ocellatus Spix, 1824. Here, we re-examine the nomenclatural issue and show that application of the nomen Dendroplex to the clade comprising the species-group D. picus (Aleixo et al. 2007) is based on a misunderstanding of the application of Article 70.3 of the Code (Anon. 1999) and that Dendrocolaptes ocellatus Spix, 1824, is its real type species. Consequently, the genus Dendroplex Swainson, 1827b, must be considered a junior synonym of Xiphorhynchus Swainson, 1827a. Because no generic nomen is currently available for them, we propose a new genus nomen to encompass the species originally described as Oriolus picus J. F. Gmelin, 1788, Dendroplex picirostris Lafresnaye, 1847, and Dendrornis kienerii Des Murs, 1856.

Taxonomic revision of Saffron-billed Sparrow Arremon flavirostris Swainson, 1838 (Aves: Passerellidae) with comments on its holotype and type locality.

The Saffron-billed Sparrow (Arremon flavirostris) complex occurs in the undergrowth of deciduous woodlands and forests from the Andes of Bolivia and northern Argentina to Paraguay and southern, mid-western and interior eastern Brazil. Currently four subspecies are recognized: A. f. flavirostris, A. f. polionotus, A. f. devillii and A. f. dorbignii. We review the taxonomy of this complex by analyzing coloration and morphometrics of a series of 234 skins, and by comparing 101 sound recordings. Our results suggest that under both the Phylogenetic and Biological Species Concept, three species should be recognized in this complex: A. flavirostris, A. polionotus and A. dorbignii. On the other hand, A. devillii should be considered a junior synonym of A. polionotus since these two have no constant differences in morphology and vocalization. These species are diagnosable by their coloration characters, but not by morphometrics. Vocalizations are useful in diagnosing A. flavirostris from A. dorbignii, but do not diagnose A. polionotus from the others. We show that part of the previous taxonomic confusion can be attributed to variation in back color of adult and immature A. polionotus. Finally, we comment on the recently located holotype of A. flavirostris, which was believed to be lost, and its type locality.