Lamprolia Finsch 1874

Lamprolia and Chaetorhynchus

Lower montane New Guinean Chaetorhynchus (Papuan Silktail) has conventionally been placed in the Old World family Dicruridae (drongos) and, with a square-tipped tail of 12, not 14 rectrices, considered “ancestral” in that family (Mayr 1941; Vaurie 1949, 1962; Rand & Gilliard 1967; Wolters 1979; Sibley & Monroe 1990; Dickinson 2003; Rocamora & Yeatman-Berthelot 2009). The enigmatic Fijian Lamprolia (Fiji Silktail) has usually been placed with Australasian monarchs (Monarchidae) in recent classifications (Pratt et al. 1987; Sibley & Monroe 1990; Dickinson 2003; Coates et al. 2006), following Olson (1980) and DNA-DNA hybridization data in Sibley & Ahlquist (1985). Beecher (1953) and Harrison & Parker (1965) referred Lamprolia to the Australo-Papuan malurid wrens (Maluridae) instead, whereas Cottrell (1967) and Heather (1977) even proposed affinities with the birds-ofparadise (Paradisaeidae). In response, Wolters (1977) placed it in its own family; and Mayr (1986) treated it as incertae sedis. In the two multilocus DNA sequence studies that have so far screened both, Chaetorhynchus and Lamprolia were recovered as sister genera with strong support (Irestedt et al. 2008; Jønsson et al. 2011). Moreover, both these studies and two more (Norman et al. 2009b; Nyǡri et al. 2009) found this lineage to be sister to the Indo- Australasian fantails (Rhipiduridae), also with strong support, distant from drongos, monarchs and birds-ofparadise.

Morphological information is limited and non-committal. No specimen material of Lamprolia was available to us other than as photographic images. Moreover, the nest and eggs of Chaetorhynchus appear to be undescribed. Even so, indicative traits of Chaetorhynchus are as much or more rhipidurid as dicrurid. Its unguinal ridge along a basally broadened mandible, dense long rictal bristling arising from below as well as above the commissure of the bill, broad palatine shelf, simple zygomatic processes, and 12 rectrices are all rhipidurid. The tarsi of Chaetorhynchus, nevertheless, are short and thick as in drongos, not long and slender as in all fantails; Lamprolia has similarly short, thick tarsi and 12 rectrices. Chaetorhynchus also differs from both drongos and fantails in its narrowed sternum; the form of the sternum in Lamprolia may thus be informative. Irestedt et al. (2008) record no shared derived morphological traits that would link Lamprolia to Chaetorhynchus or the fantails exclusive of the monarchs (cf. Olson 1980). Yet despite a dearth of indicative morphological information, the corroborated DNA phylogenies resolve the phylogenetic position of these genera with reasonable certainty: they are based on comprehensive taxon sampling of 23 to 72 corvoid genera, use markers from two mitochondrial regions and four nuclear genes, and have robust support. DNA distances from Rhipidura are deep, Jønsson et al. (2011) dating the divergence at around the middle Oligocene. This may justify family ranking in the future, but we prefer a conservative approach at this stage and treat the Chaetorhynchus - Lamprolia group as a subfamily, Lamproliinae, in the Rhipiduridae (fantails) to indicate its phylogenetic affinities. Although Wolters (1977) used the name, he provided no description, leaving it a nomen nudum (Article 13.1 of the Code). The other subfamily, Rhipidurinae Sundevall, 1872, comprises the single genus Rhipidura.