Phylogeny of snout butterflies (Lepidoptera: Nymphalidae: Libyt- heinae): combining evidence from the morphology of extant, fossil, and recently extinct taxa

Snout butterflies (Nymphalidae: Libytheinae) are morphologically one of the most unusual groups of Lepidoptera. Relationships among libytheines remain uncertain, especially in the placement of the recently extinct Libythea cinyras and two fossils, L. florissanti, and L. vagabunda. The aim of this study is to present the first phylogenetic hypothesis of Libytheinae utilizing all available morphological data from extant and extinct species. Forty-three parsimony-informative characters were coded, and the alltaxa analysis resulted in six most parsimonious trees (length 92 steps, CI = 0.66, RI = 0.82). The subfamily was resolved as monophyletic and was split into Old World and New World clades. Inclusion of extinct species with considerable missing data had little effect on relationships of extant taxa, although Bremer support values and jackknife frequencies generally decreased if extinct species were included. In order to preserve the monophyly of extant genera, two fossils are assigned to Libytheana for the first time (L. florissanti comb. n. and L. vagabunda comb. n.). This study demonstrates the value of morphological data in phylogenetic analysis, and highlights the contribution that can be made by scoring extinct taxa and including them directly into the analysis. The Willi Hennig Society 2009. Unusual morphological features and well preserved fossils of snout butterflies (Nymphalidae: Libytheinae) have long fascinated morphologists, taxonomists, and paleontologists studying the Lepidoptera. Libytheines have an extraordinarily long labial palpus or snout projecting from the front of the head (Fig. 1), and a fully developed female foreleg that is reduced in all other Nymphalidae. The 12 extant species (Fig. 2) include some broadly distributed migratory continental species and others that are restricted to isolated islands (Shields, 1985a; Kawahara, in press). Unlike most Nymphalidae, the larva of snout butterflies lacks horns or spines, and superficially resembles the larva of Pieridae (Fracker, 1915; Shirozu and Hara, 1960; Shields, 1989). Such characteristics led many traditional studies to treat libytheines as a separate butterfly family (e.g. Hering, 1921; Holland, 1931; Peile, 1937; Shirozu, 1960). Following the advent of modern cladistic methodology (Hennig, 1950, 1965, 1966), libytheines were included in Nymphalidae as a subfamily, because they share uniquely with Nymphalidae the presence of longitudinal ridges on the antenna (Kristensen, 1976; Ackery et al., 1998). Morphological and molecular phylogenetic analyses support the inclusion of Libytheinae within Nymphalidae (e.g. de Jong et al., 1996; Weller et al., 1996; Brower, 2000; Wahlberg et al., 2003, 2005a), and more precisely, libytheines are considered to be sister to the remaining Nymphalidae because they lack apomorphic features such as the simple female foreleg (Ehrlich, 1958; Ackery, 1984; Scott, 1985; Scott and Wright, 1990; Harvey, 1991; Martin and Pashley, 1992; de Jong et al., 1996; Freitas, 1999; Freitas and Brown, 2004). However, relationships within the subfamily have not been examined in a modern cladistic *Corresponding author: E-mail address: [email protected] The Willi Hennig Society 2009 Cladistics 10.1111/j.1096-0031.2009.00251.x Cladistics 25 (2009) 263–278 context as phylogenetic studies that included snout butterflies have focused on higher nymphalid relationships with typically only one or two extant libytheine exemplars. Historically, there have been attempts to resolve relationships of libytheine species. Pagenstecher (1901) assigned all then known extant taxa to three subgenera, Dichora Scudder, Hypatus Hübner, and Libythea Fabricius, and relationships following Pagenstecher are shown in Fig. 3a. Hering (1921) examined distributional Fig. 1. Lateral view of the libytheine head (anterior = left). The snout or labial palpus extends forward from the front of the head. (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) Fig. 2. Adult representatives of Libytheinae. Right dorsal surface shown. Scale 1 cm. (a) Libythea celtis, Russia; (b) L. lepita, Japan; (c) L. myrrha, India; (d) L. collenettei, French Polynesia; (e) L. narina, Philippines; (f) L. geoffroy, Papua New Guinea; (g) L. labdaca, Cameroon; (h) L. laius, Mozambique; (i) Libytheana carinenta, Brazil; (j) L. fulvescens, Dominica; (k) L. motya, Cuba; (l) L. terena, Dominican Republic. All are males except L. motya.