Saturday, November 26, 2016

[Ornithology • 2016] Resolving Taxonomic Uncertainty and Historical Biogeographic Patterns in Muscicapa Flycatchers and their allies





Highlights
• We use mitochondrial and nuclear genes to resolve relationships in Muscicapa and allies.
• We use our phylogenetic results to reconstruct biogeographic history in the group.
• We find several genera to be non-monophyletic.
• The group originated in Africa, and subsequently colonized Eurasia.
• The Congolian region of Africa is ancestral for one of the two major clades in the group.

Abstract
Muscicapa flycatchers and their allies (Bradornis, Dioptornis, Empidornis, Fraseria, Myioparus, Namibornis, and Sigelus) are widely distributed in Africa, Europe and Asia. This broad distribution and the wide variety of habitats occupied by the group, ranging from arid to tropical forests, presents an interesting opportunity to explore the evolution of biogeographic patterns and habitat associations. Sequence data (up to 3310 base pairs from two mitochondrial and two nuclear genes) were generated for 36 of 42 species which comprise the assemblage. Complementary data from an additional species was retrieved from GenBank, as was an additional gene which was available for 21 of our included taxa. Using model-based phylogenetic methods and molecular clock dating, we constructed a time-calibrated molecular phylogenetic hypothesis for the lineage. Ancestral area reconstructions were performed on the phylogeny using LaGrange and BioGeoBEARS. Our results indicate that BradornisFraseria, and Muscicapa are each non-monophyletic, with the latter being shown to comprise five separate clades each more closely related to other genera. Two new genera (Chapinornis Chapinia and Ripleyornis Ripleyia) are erected to account for these results. Muscicapa and allies originated c. 7.4 Ma, most likely in Africa given that their sister lineage is almost entirely from there, and rapidly achieved a Eurasian distribution by c. 7.1 Ma. A second divergence at c. 6.1 Ma resulted in two clades. The first is a largely Eurasian clade that subsequently recolonized Africa, perhaps as the result of the loss of migration. The second is an African clade, and ancestral reconstructions suggest a Congolian (e.g. tropical forest) origin for this clade, with several subsequent diversifications into more arid habitats. This is a unique result, as most tropical forest lineages are confined to that habitat. As with other studies of African bird lineages, Afrotropical forest dynamics appear to have played a significant role in driving diversification in Muscicapa and allies, and our results include just the second recorded case of southern to northern African colonization patterns.

Keywords: Africa; Eurasia; Historical biogeography; Muscicapa; Muscicapidae; Systematics


Molecular phylogeny and taxonomic implications

Using molecular data from 20 taxa, Sangster et al. (2010) defined Muscicapini as comprising the genera Muscicapa, Melaenornis and, Fraseria; they did not include Myioparus in their analysis but it is clearly also a member of Muscicapini ( Fig. 1). Other genera ascribed to Muscicapini historically were excluded by their results, which also indicated issues with the monophyly of each of the remaining three genera (Muscicapa, Melaenornis, and Fraseria; Sangster et al., 2010).

Our study represents the most extensively sampled molecular phylogenetic analysis of Muscicapini species to date. Overall, we included 37 of 42 Muscicapini species (see Section 2). Of the five taxa we are missing in our analyses, two are insular forms from Southeast Asia (Muscicapa randi – Philippines and Muscicapa segregata – Lesser Sundas), and both have been considered as conspecific with Muscicapa dauurica ( Taylor, 2006). The remaining three species have patchy or restricted ranges in Afrotropical rainforests (Muscicapa lendu, Muscicapa epulata, Melaenornis annamarulae). Our attempts to extract DNA from museum specimens of Muscicapa lendu and Muscicapa epulata were unsuccessful.

Although comprising just four species in recent taxonomy (e.g., Taylor, 2006), the genus Melaenornis has previously been considered to include species now ascribed to Empidornis, Sigelus, Dioptrornis, Bradornis, and Fraseria ( Mayr and Cottrell, 1986). Our results indicate, (1) that a larger Melaenornis (to include the aforementioned four genera) would be non-monophyletic (see also Sangster et al., 2010), (2) that Melaenornis (edolioides is the type) could be restricted to as little as three and perhaps four species (depending on the eventual systematic placement of annamarulae), and (3) that Melaenornis could be expanded to include Dioptrornis, Empidornis, Sigelus and Namibornis ( Fig. 1 and Fig. 2). Due to the morphological distinctiveness of the latter four genera (three of which are monotypic) relative to Melaenornis, which are all black or dark gray in color, we agree with the more strict usage of Melaenornis (e.g., Taylor, 2006).


Our results also indicate that Bradornis is non-monophyletic, with species falling into two distinct clades ( Fig. 1 and Fig. 2). The Bradornis type is mariquensis ( Mayr and Cottrell, 1986), and thus that genus should be applied to mariquensis, pumilus and microrhyncus. There is an available synonym, Haganopsornis, which was applied to infuscatus (Roberts, 1922 fide Mayr and Cottrell, 1986) and we suggest resurrecting that genus to include infuscatus and pallidus ( Fig. 1 and Fig. 2). The genus Fraseria is also non-monophyletic, with ocreata being more closely related to the genus Myioparus; our results conflict as to the phylogenetic position of cinerascens ( Fig. 1 and Fig. 2). Regardless, Fraseria would apply to ocreata ( Mayr and Cottrell, 1986). We find no synonym to apply to cinerascens, which then requires the designation of a new genus for that species which we propose as:


Chapinia, new genus Voelker & Bowie
Type species. – Chapinia cinerascens.

Diagnosis – A genus of muscicapid flycatcher differing from all other genera of the family Muscicapidae by the following combination of characters: large size, diagnostic white supra-loral spot, dark upperparts, and mottled gray underparts with dark but poorly demarcated crescents on the breast.

Etymology – This name honors Dr. James P. Chapin, for his extensive documentation of, and research on, the birds of the Belgian Congo.


Finally, the genus Muscicapa appears to have been a taxonomic dumping ground for any small to medium sized Muscicapini flycatcher, as our results show it to be comprised of five distinct lineages (Fig. 1). The type for the genus is striata, thus Muscicapa would apply to the large clade of 11 species (Fig. 1). There are several synonyms available for other clades. The genus Apatema could be applied to olivascens, and Cichlomyia or Butalis (it is unclear to us which has priority) could apply to the closely related caerulescens, and thus to tessmani as well (Fig. 1). For comitata, the genus Pedilorhynchus is available, and Artomyias is available for infuscata and thus also for the closely related ussheri (Fig. 1). Although sister to infuscata + ussheri, boehmi is highly distinct from them morphologically (Sinclair and Ryan, 2010). We therefore suggest applying the name Bradyornis to boehmi, following the original description of this species (Reichenow, 1884, fide Mayr and Cottrell, 1986). We find no available synonym for ruficauda, which is the first species to diverge within Muscicapini (Fig. 1). This requires the designation of a new genus for that species which we propose as:


Ripleyia, new genus Voelker & Bowie
Type species. – Ripleyia ruficauda.

Diagnosis – A genus of muscicapid flycatcher differing from all other genera of the family Muscicapidae by the following combination of characters: rufous uppertail-coverts and tail, faint supercilium, and entirely orange lower mandible.

Etymology – This name honors Dr. S. Dillon Ripley, former Secretary of the Smithsonian Institution, for his extensive work on the birds of India and southern Asia.


Gary Voelker, Jerry W. Huntley, Joshua V. Peñalba and Rauri C.K. Bowie. 2016. Resolving Taxonomic Uncertainty and Historical Biogeographic Patterns in Muscicapa Flycatchers and their allies. Molecular Phylogenetics and Evolution. 94, Part B; 618–625. DOI: 10.1016/j.ympev.2015.09.026


   

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Abstract
  

Earlier this year, two of us (GV & RB) introduced the genus-group names Chapinia and Ripleyia (in Voelker et al. 2016) for two species of African flycatchers allied to Muscicapa. We recently became aware that both of these genus-group names are preoccupied within Animalia (Chapinia by Chapinia Ewing, 1927 [Insecta: Phthiraptera] and Ripleyia by Ripleyia Cossman, 1920 [Mollusca]), rendering them junior homonyms. Following Article 60 of the International Code of Zoological Nomenclature (ICZN 1999) we herein provide replacement names for the two generic names introduced in Voelker et al. (2016).

Keywords: ChapiniaRipleyia, Passeriformes, Muscicapidae, Aves



Chapinornisnew replacement name
Type species: Fraseria cinerascens Hartlaub, 1857

Etymology: A combination of the surname Chapin and the Greek ὄρνις (Ornis), a bird, and a common suffix for bird genera. This name honors James P. Chapin, for his extensive documentation of, and research on, the birds of the Belgian Congo. Gender masculine.

Remarks: Replacement name for Chapinia Voelker & Bowie in Voelker, Huntley, Peñalba & Bowie, 2016.

Ripleyornisnew replacement name
Type species: Muscicapa ruficauda Swainson, 1838

Etymology: A combination of the surname Ripley and the Greek ὄρνις (Ornis), a bird, and a common suffix for bird genera. This name honors S. Dillon Ripley, former Secretary of the Smithsonian Institution, for his extensive work on the birds of India and southern Asia. Gender masculine.

Remarks: Replacement name for Ripleyia Voelker & Bowie in Voelker, Huntley, Peñalba & Bowie, 2016.


 Gary Voelker, Rauri C K Bowie and Kevin W. Conway. 2016. Replacement names for Chapinia and Ripleyia (Aves: Passeriformes: Muscicapidae).
Zootaxa. 4107(4); 599. DOI:  10.11646/zootaxa.4107.4.9

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