Phylogenetic interrelationships of the barbets (Aves: Capitonidae) and toucans (Aves: Ramphastidae) based on morphology with comparisons to DNA-DNA hybridization

Abstract

A phylogenetic analysis of the interrelationships of the barbets (Capitonidae) and the toucans (Aves: Ramphastidae, Superfamily Ramphastoidea) is presented. Thirty‐two morphological characters from the literature and independent osteological observations were analysed. Character polarity was determined by outgroup comparison to the Picidae, Indicatoridae, Galbulidae, Bucconidae and Coraciiformes. Four alternative phylogenetic hypotheses were compared: (1) the overall most parsimonious morphological phylogeny, (2) the most parsimonious morphological phylogeny in which the capitonids and ramphastids were hypothesized as monophyletic sister groups, and (3) and (4) the most parsimonious hypotheses for the evolution of the morphological characters within two proposed DNA‐DNA hybridization phylogenies of the ramphastoids. The analysis focused on the higher level relationships of ramphastids and capitonids and interrelationships among capitonid genera. Two cladistic analyses were performed using 26 phylogenetically informative characters, and the PAUP and CONTREE computer alogorithms. The most parsimonious morphological phylogeny required fewer character changes and had a lower consistency index than any of the alternative hypotheses but congruence between the most parsimonious phylogeny and the second, revised DNA‐DNA hybridization hypothesis was very high. Based on these results the monophyly of the Capitonidae is rejected. The ramphastids and the Neotropical capitonids form a well corroborated clade within the pantropical ramphastoid radiation. Neither the African, Asian nor New World capitonids is monophyletic. The genus Trachyphonus is the sister group to all other capitonids and ramphastids. The sister group to the ramphastids is the genus Semnornis. The interrelationships of the Old World capitonids excluding Trachyphonus are not completely resolved by these morphological data but one of the alternative phylogenetic resolutions is presented as a preliminary hypothesis. The clades in this resolved phylogeny are diagnosed and the palaeontology and biogeography of the ramphastoids arc‐reviewed in light of this new evidence. A phylogenetic classification is proposed in which the Capitonidae is rejected and the capitonids and ramphastids are placed in seven subfamilies of the Ramphastidae.

Diversification of Ramphastinae (Aves, Ramphastidae) prior to the Cretaceous/Tertiary boundary as shown by molecular clock of mtDNA sequences

“…Barker and Lanyon (2000) analyzed 888 cytochrome b base-pairs from at least two species of each genus through a plethora of weighting schemes for maximum parsimony (MP) and proposed a phylogenetic hypothesis involving all Ramphastidae genera. Their results indicated Capitoninae (New and Old World barbets) as well as New World barbets to be paraphyletic, as suggested before (Prum, 1988;Sibley and Ahlquist, 1990), besides a very robust topology among the toucans and aracaris (Ramphastinae). Among these, the clade leading to Ramphastos was the first to split off, followed by Aulacorhynchus as a sister to ((Andigena, Selenidera), (Baillonius, Pteroglossus)).…”

The Impact of Parsimony Weighting Schemes on Inferred Relationships among Toucans and Neotropical Barbets (Aves: Piciformes)

“…This hypothesis has also been corroborated by genetic analyses (Sibley and Ahlquist, 1990;Harshman, 1994;Lanyon and Hall, 1994). Second, based upon his analysis of the only data set with complete genus-level sampling within the Capitonidae to date, Prum (1988) suggested not only that barbets as a whole are paraphyletic but that Neotropical barbets are themselves paraphyletic, with Semnornis more closely related to the toucans than to other Neotropical barbets (Fig. 1).…”

“…The sampling of Lanyon and Hall (1994) was expanded to include two members of each genus of toucans and Neotropical barbets (excepting Aulacorhynchus, for which only one species was sampled), as well as several additional genera of Paleotropical barbets (see Table 1). Based upon the results of morphological (Simpson and Cracraft, 1981;Swierczewski and Raikow, 1981;Prum, 1988) and molecular (Lanyon and Zink, 1987;Sibley and Ahlquist, 1990;Harshman, 1994) studies, sequences of the Picidae (Moore and DeFilippis, 1997) were included in analyses as an outgroup to the Ramphastidae (Table 1).…”

“…First, monophyly of the barbets as traditionally defined (family Capitonidae, sensu Peters, 1948) has been called into question. Specifically, it was suggested on morphological grounds that the very distinctive toucans (family Ramphastidae, sensu Peters, 1948) are in fact a highly derived lineage of barbets, most closely related to the Neotropical barbets (Capito, Eubucco, and Semnornis; Burton, 1984;Prum, 1988), thus rendering the traditional Capitonidae paraphyletic. This hypothesis has also been corroborated by genetic analyses (Sibley and Ahlquist, 1990;Harshman, 1994;Lanyon and Hall, 1994).…”

“…Under the maximum-likelihood criterion, the test of Kishino and Hasegawa (1989) was used. The alternative topologies tested were the best trees under a given criterion, employing the following constraints: (1) barbet (nonramphastine) monophyly, (2) Neotropical barbet monophyly, (3) Paleotropical barbet monophyly, (4) Prum's (1988) estimate of relationships ( Fig. 1), (5) Trachyphonus constrained as basal within Ramphastidae, and (6) Semnornis constrained as sister group to the ramphastines.…”