RHINOCRYPTIDAE, WETMORE, 1926

Maurício, Giovanni Nachtigall, Areta, Juan Ignacio, Bornschein, Marcos Ricardo & Reis, Roberto E., 2012, Morphology-based phylogenetic analysis and classification of the family Rhinocryptidae (Aves: Passeriformes), Zoological Journal of the Linnean Society 166 (2), pp. 377-432 : 417-418

MONOPHYLY OF RHINOCRYPTIDAE

The present morphology-based analysis constitutes a robust test of monophyly of the family as it includes representatives of all families of the infraorder Furnariides and all genera of Rhinocryptidae – including a heterogeneous sampling of the highly speciose genus Scytalopus . The only other study aimed at testing the monophyly of the family was the recent sequence-based analysis presented by Ericson et al. (2010), which included representatives of most families of Furnariides (except Scleruridae) and all rhinocryptid genera, but a much less heterogeneous sampling of Scytalopus . The two studies are therefore complementary. The Rhinocryptidae as recovered in our morphological phylogeny is perfectly congruent with all molecular phylogenies with adequate taxonomic coverage ( Moyle et al., 2009; Ericson et al., 2010) in excluding the genus Melanopareia from the family and supporting the allocation of the problematic genera Psilorhamphus and Teledromas within Rhinocryptidae . The resulting monophyletic Rhinocryptidae has strong Bremer support (i.e. 6), includes 12 genera ( Liosceles , Psilorhamphus , Eleoscytalopus , Merulaxis , Acropternis , Rhinocrypta , Teledromas , Pteroptochos , Scelorchilus , Eugralla , Myornis , and Scytalopus ), and is defined by the following eight synapomorphies, the first four of which are features not previously mentioned for the family: nonpneumatized ectethmoid (char. 19.1), absence of foramen in the medial face of the brachial tuberosity of the coracoid (char. 43.0), ulna as long as or shorter than humerus (char. 48.1), distance between the posterior projections of the ilium nearly equal to the width of the caudalmost sacral vertebrae (char. 50.2), absence of a foramen in the medial process of the mandible (char. 38.1), caudal margin of the sternum with two pairs of notches (char. 42.2), lacrimal partially fused to the ectethmoid (char. 26.1), and parietal and frontal bones largely non-pneumatized (char. 31.1). Additionally, the last four characters have never been formally suggested as synapomorphic for the family, although the last two have been regarded as ‘characteristics that unite members of the tapaculo family’ (termed ‘lachrymal bones fused into the ectethmoid’ and ‘incomplete skull ossification’, respectively) by Krabbe & Schulenberg (2003: 752). The four-notched sternum was optimized as a synapomorphy of the Rhinocryptidae in the only previous morphology-based cladistic study that included members of the family ( Pteroptochos and Rhinocrypta ) ( Claramunt & Rinderknecht, 2005), judging from the consensus tree and the data matrix presented.

Below, a detailed account regarding the systematic placement of each of the ‘problematic’ genera is provided.

Melanopareia: Comprehensive taxon and character sampling is particularly important to elucidate the position of Melanopareia because morphology-based studies ( Ames, 1971; Feduccia & Olson, 1982) found it natural to place Melanopareia within Rhinocryptidae , as first suggested by W. W. Miller on the basis of this genus’ possession of a four-notched sternum ( Wetmore, 1926). However, these morphological studies did not include cladistic analyses of characters and based their decisions solely upon particular features whose systematic value is subjective if not analysed within a strict cladistic context. Feduccia & Olson (1982) noted that Melanopareia lacked some features typical of rhinocryptids such as the absence of a foramen in the medial process of the mandible but concluded that ‘... our examination showed its osteology to be in accordance with its placement in the Rhinocryptidae’ (p. 6). However, apart from some general similarities, one can find only two objective characters in the literature that would support Melanopareia as part of the Rhinocryptidae , namely the possession of a lacrimal partially fused to the ectethmoid and the four-notched sternum ( Feduccia & Olson, 1982; Krabbe & Schulenberg, 2003; Ericson et al., 2010). On the basis of material available for the present study, however, the lacrimal was not partially fused to the ectethmoid in Melanopareia , and instead its lacrimal was found to be completely fused to the ectethmoid with no signs of suture, as in the great majority of the members of Furnariides . On the other hand, a number of character-states – including the four-notched sternum – were found here to occur in the Rhinocryptidae and in the Melanopareiidae ( Fig. 43 ), but these shared conditions were solidly optimized in the parsimony analysis as convergences between distantly related groups: Melanopareia was part of a polytomy with the families Conopophagidae , Grallariidae , Thamnophilidae , and a large, structured clade that included Formicariidae , Scleruridae, Furnariidae , Dendrocolaptidae , and Rhinocryptidae . Another morphological feature that supports the exclusion of Melanopareia from the Rhinocryptidae is its retention of the primitive morphology of the stapes (flat footplate) instead of the typical suboscine condition present in all rhinocryptids (inflated footplate), including Psilorhamphus and Teledromas ( Feduccia, 1974; Ericson et al., 2010). In any event, the present morphology-based phylogeny corroborates the erection of the family-level taxon Melanopareiidae for the genus Melanopareia as first proposed by Irestedt et al. (2002) and later formalized by Ericson et al. (2010).

Psilorhamphus: Although it has been suggested that Psilorhamphus might lie outside Rhinocryptidae ( Ridgely & Tudor, 1994) and that it bears little external resemblance to typical members of the family ( Krabbe & Schulenberg, 2003; Ericson et al., 2010), Psilorhamphus proved to be a typical member of the group in terms of osteology, with 12 synapomorphies supporting it as a rhinocryptid (eight in the family node and four in the subsequent node) and no character state linking it to other family of Furnariides (see Fig. 43 ). Therefore, the allocation of the genus to the Rhinocryptidae as first implemented by Plótnick (1958) was a correct systematic decision, with two of the characters that supported this author’s decision –M. sternotrachealis originating in the vertebral segment of the second rib and presence of two pairs of notches in the sternum – having been cladistically optimized here as support for such a placement (the first character for the Formicariidae + Furnariidae + Scleruridae + Dendrocolaptidae + Rhinocryptidae clade and the latter for the rhinocryptid clade). Recent molecular phylogenies also corroborated this placement ( Maurício et al., 2008; Ericson et al., 2010).

Teledromas: Based on similarity of vocalizations ( Ridgely & Tudor, 1994; N. Krabbe, unpubl. data), general shape, details of the nasal operculum, tarsal scutellation, flank pterylography, and straight shape of humerus between Teledromas and Melanopareia, Irestedt et al. (2002) suggested that they were members of the same clade. Given that Melanopareia proved to be a distinct lineage of uncertain affinities, they placed both genera in the new family Melanopareiidae even though no sequence data of Teledromas were available. Subsequent molecular phylogenies that included Teledromas samples showed this genus to be well embedded within Rhinocryptidae ( Moyle et al., 2009; Ericson et al., 2010), a placement corroborated in the present analysis. In fact, anatomically Teledromas is very similar to Rhinocrypta , both having several shared derived character states (see above). The alleged similarity of Teledromas to Melanopareia ( Irestedt et al., 2002) , at least in terms of general aspect and shape of the humerus, found no support here. Moreover, although vocalizations were considered as the main evidence for a close link between Teledromas and Melanopareia ( Irestedt et al., 2002; Ericson et al., 2010) detailed structural analyses of the vocal repertoire of Teledromas support its inclusion within the Rhinocryptidae (J. I. Areta, unpubl. data).

Figures

Figure 43. Strict consensus of 7428 equally most parsimonious trees derived from the cladistic analysis of the character state matrix in Appendix 2. On each branch, solid circles indicate exclusive synapomorphies and open circles homoplastic traits; numbers above circles represent characters as numbered in the character analysis section, with correspondig character-states appearing below circles. All characters are non-additive (except char. 74, whose states are ordered based on ontogenetic evidence) and unweighted. Bremer support indices are shown in parentheses above character numbers. Vertical bars on the right indicate family boundaries: A, Tyrannidae; B, Conopophagidae; C, Melanopareiidae; D, Grallariidae; E, Thamnophilidae; F, Formicariidae; G, Scleruridae; H, Furnariidae; I, Dendrocolaptidae; J, Rhinocryptidae.