On the phylogenetic relationships of trogons (Aves, Trogonidae)

Although trogons (Aves, Trogonidae) are well characterized by the possession of heterodactyl feet, their phylogenetic relationships to other extant birds still are only poorly understood. Molecular studies did not show conclusive results and there are amazingly few comparative studies of the anatomy of trogons. Virtually the only hypothesis on trogon relationships that was supported with derived morphological characters is a sister group relationship to alcediniform birds (bee-eaters, kingfishers, and allies), which share a derived morphology of the columella (ear-ossicle) with trogons. However, in this study a very similar columella is reported for the oilbird (Steatornithidae) and additional previously unrecognized derived osteological characters are presented, which are shared by trogons and oilbirds. A numerical cladistic analysis of 28 morphological characters also resulted in monophyly of Trogonidae and Steatornithidae, although the corresponding node was not retained in a bootstrap analysis.     

Tertiary plotopterids (Aves, Plotopteridae) and a novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae)

Plotopterids (Aves: Plotopteridae) are extinct wing-propelled diving birds which exhibit a strikingly similar wing morphology to penguins (Spheniscidae), but also share derived characters with 'pelecaniform' birds that are absent in penguins. The similarities between Plotopteridae and Spheniscidae have hitherto been attributed to convergence, and plotopterids were considered to be most closely related to the 'pelecaniform' Phalacrocoracidae (cormorants) and Anhingidae (anhingas). However, here I show that assignment of plotopterids to 'pelecaniform' birds does not necessarily preclude them from being the sister taxon of penguins. Cladistic analysis of 68 morphological characters resulted in sister group relationship between Plotopteridae and Spheniscidae, and the clade (Plotopteridae + Spheniscidae) was shown to be the sister taxon of the Suloidea, i.e. a clade including Sulidae (boobies and gannets), Phalacrocoracidae, and Anhingidae. Derived characters are discussed which support this novel hypothesis. Paedomorphosis probably accounts for the absence of derived characters in penguins that are shared by Plotopteridae and members of the Steganopodes. Plotopterids exemplify the importance of fossil birds for analyzing the phylogenetic relationships of modern taxa that exhibit a highly apomorphic morphology.     

Multiple gene sequences resolve phylogenetic relationships in the shorebird suborder Scolopaci (Aves: Charadriiformes)

Shorebirds (Charadriiformes) are a diverse assemblage of species renowned for their variation in behavior, morphology, and life-history traits, but comparative studies of trait variation remain limited by the lack of a well-supported phylogeny based on DNA sequences. In this study we build upon previous shorebird phylogenies to construct the first sequence-based species-level phylogeny for the Scolopaci, one of three shorebird suborders. We sampled 84 species in the Scolopaci, and collected data for five genes (one nuclear and four mitochondrial) via PCR and sequencing or from GenBank. The phylogeny was estimated using Bayesian inference on a partitioned dataset of 6365 aligned base pairs, and was well-supported except for the radiations within Tringa and Calidris. The shanks and phalaropes are sister to the snipes, woodcocks and dowitchers, which in turn are sister to the sandpipers. The godwits and curlews are successive sister-groups to these clades, and the morphologically disparate taxa (jacanas, painted snipes, seedsnipes, and the Plains-wanderer) are the basal sister-group in the Scolopaci. We show that Tringa, Gallinago, and Calidris are paraphyletic assemblages, and thus are in need of taxonomic revision. The clade of Calidridine sandpipers has very short internal branches indicative of a relatively recent rapid radiation, and will require a gene tree/species tree approach to resolve relationships among species.     

A phylogenetic supertree of the fowls (Galloanserae, Aves)

The fowls (Anseriformes and Galliformes) comprise one of the major lineages of birds and occupy almost all biogeographical regions of the world. The group contains the most economically important of all bird species, each with a long history of domestication, and is an ideal model for studying ecological and evolutionary patterns. Yet, despite the relatively large amount of systematic attention fowls have attracted because of their socio‐economic and biological importance, the species‐level relationships within this clade remain controversial. Here we used the supertree method matrix representation with parsimony to generate a robust estimate of species‐level relationships of fowls. The supertree represents one of the most comprehensive estimates for the group to date, including 376 species (83.2% of all species; all 162 Anseriformes and 214 Galliformes) and all but one genera. The supertree was well‐resolved (81.1%) and supported the monophyly of both Anseriformes and Galliformes. The supertree supported the partitioning of Anseriformes into the three traditional families Anhimidae, Anseranatidae, and Anatidae, although it provided relatively poor resolution within Anatidae. For Galliformes, the majority‐rule supertree was largely consistent with the hypothesis of sequential sister‐group relationships between Megapodiidae, Cracidae, and the remaining Galliformes. However, our species‐level supertree indicated that more than 30% of the polytypic genera examined were not monophyletic, suggesting that results from genus‐level comparative studies using the average of the constituent species’ traits should be interpreted with caution until analogous species‐level comparative studies are available. Poorly resolved areas of the supertree reflect gaps or outstanding conflict within the existing phylogenetic database, highlighting areas in need of more study in addition to those species not present on the tree at all due to insufficient information. Even so, our supertree will provide a valuable foundation for understanding the diverse biology of fowls in a robust phylogenetic framework.     

Molecular phylogenetic relationships of Xiphidiopicus percussus, Melanerpes, and Sphyrapicus (Aves: Picidae) based on cytochrome B sequence

The endemic woodpecker, Xiphidiopicus percussus, from Cuba has been postulated as the sister taxon to the Hispaniolan woodpecker (Melanerpes striatus) and its relationships to the genera Sphyrapicus and Melanerpes have been speculated. We used mitochondrial cytochrome b sequences from a collection of New World picids to investigate the phylogenetic relationships among these species using maximum parsimony and maximum likelihood approaches. Our data suggest that X. percussus is the sister taxon to the Melanerpes woodpeckers, which appear to group into a single distinct clade. Xiphidiopicus percussus is not the sister taxon to M. striatus as has been postulated [Olson, S., 1972. The generic distinction of the Hispaniolan Woodpecker, Chryserpes striatus (Aves: Picidae). Proc. Biol. Soc. Wash. 85, 499-508]. The genus Sphyrapicus appears to have diverged earlier than Xiphidiopicus. Divergence estimates from the cytochrome b sequences indicate that Xiphidiopicus probably diverged sometime in the late Miocene-early Pliocene, and the endemic contemporary species X. percussus on Cuba may be a relict from a group that originated in Central America or North America.     

A phylogenetic analysis of the Gruiformes (Aves) based on morphological characters,with an emphasis on the rails (Rallidae)

The order Gruiformes, for which even familial composition remains controversial, is perhaps the least well understood avian order from a phylogenetic perspective. The history of the systematics of the order is presented, and the ecological and biogeographic characteristics of its members are summarized. Using cladistic techniques, phylogenetic relationships among fossil and modern genera of the Gruiformes were estimated based on 381 primarily osteological characters; relationships among modern species of Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae) were assessed based on these characters augmented by 189 characters of the definitive integument. A strict consensus tree for 20,000 shortest trees compiled for the matrix of gruiform genera (length = 967, CI = 0.517) revealed a number of nodes common to the solution set, many of which were robust to bootstrapping and had substantial support (Bremer) indices. Robust nodes included those supporting: a sister relationship between the Pedionomidae and Turnicidae; monophyly of the Gruiformes exclusive of the Pedionomidae and Turnicidae; a sister relationship between the Cariamidae and Phorusrhacoidea; a sister relationship between a clade comprising Eurypyga and Messelornis and one comprising Rhynochetos and Aptornis; monophyly of the Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae); monophyly of a clade (Gruoidea) comprising (in order of increasingly close relationship) Psophia, Aramus, Balearica and other Gruidae, with monophyly of each member in this series confirmed; a sister relationship between the Heliornithidae and Rallidae; and monophyly of the Rallidae exclusive of Himantornis. Autapomorphic divergence was comparatively high for Pedionomus, Eurypyga, Psophia, Himantornis and Fulica; extreme autapomorphy, much of which is unique for the order, characterized the extinct, flightless Aptornis. In the species-level analysis of modern Grues, special efforts were made to limit the analytical impacts of homoplasy related to flightlessness in a number of rallid lineages. A strict consensus tree of 20,000 shortest trees compiled (length = 1232, CI = 0.463) confirmed the interfamilial relationships resolved in the ordinal analysis and established a number of other, variably supported groups within the Rallidae. Groupings within the Rallidae included: monophyly of Rallidae exclusive of Himantornis and a clade comprising Porphyrio (including Notornis) and Porphyrula; a poorly resolved, basal group of genera including Gymnocrex, Habroptila, Eulabeornis, Aramides, Canirallus and Mentocrex; an intermediate grade comprising Anurolimnas, Amaurolimnas, and Rougetius; monophyly of two major subdivisions of remaining rallids, one comprising Rallina (paraphyletic), Rallicula, and Sarothrura, and the other comprising the apparently paraphyletic ''long-billed'' rails (e.g. Pardirallus, Cyanolimnas, Rallus, Gallirallus and Cabalus and a variably resolved clade comprising ''crakes'' (e.g. Atlantisia, Laterallus and Porzana, waterhens (Amaurornis), moorhens (Gallinula and allied genera) and coots (Fulica). Relationships among ''crakes'' remain poorly resolved; Laterallus may be paraphyletic, and Porzana is evidently polyphyletic and poses substantial challenges for reconciliation with current taxonomy. Relationships among the species of waterhens, moorhens and coots, however, were comparatively well resolved, and exhaustive, fine-scale analyses of several genera (Grus, Porphyrio, Aramides, Rallus, Laterallus and Fulica) and species complexes (Porphyrio porphyrio -group,Gallirallus philippensis -group and Fulica americana -group) revealed additional topological likelihoods. Many nodes shared by a majority of the shortest trees under equal weighting were common to all shortest trees found following one or two iterations of successive weighting of characters. Provisional placements of selected subfossil rallids (e.g. Diaphorapteryx, Aphanapteryx and Capellirallus ) were based on separate heuristic searches using the strict consensus tree for modern rallids as a backbone constraint. These analyses were considered with respect to assessments of robustness, homoplasy related to flightlessness, challenges and importance of fossils in cladistic analysis, previously published studies and biogeography, and an annotated phylogenetic classification of the Gruiformes is proposed.     

Phylogenetic relationships of fantails (Aves: Rhipiduridae)

We explore the phylogenetic relationships of fantails (Aves: Rhipiduridae) using molecular characters derived from two nuclear introns and two mitochondrial genes. Our results indicate that Rhipidura hypoxantha is not a true fantail, but rather a member of the Stenostiridae clade that is morphologically and behaviourally convergent with fantails. Within the true Rhipiduridae, we identified six distinct clades; however, phylogenetic relationships among these groups were unresolved. The only well-supported sister relationship was between members of the grey and the rufous fantail complexes. Clades recovered through our model-based phylogenetic analyses generally correspond to previously proposed fantail complexes based on morphological characters. The phylogenetic position of R. atra and R. diluta remain unclear, as sister relationships varied between analyses for the prior whereas the latter was placed as sister to the New Guinea thicket fantails, R. leucothorax and R. threnothorax ; yet significant node support was not recovered for either taxa. Biogeographically, fantails appear to have radiated rapidly and the six clades are not geographically restricted, but instead span South-east Asia, New Guinea, Australia and Pacific Islands.     

A reconsideration of Gallicolumba (Aves: Columbidae) relationships using fresh source material reveals pseudogenes,chimeras, and a novel phylogenetic hypothesis

Phylogenetic analyses of nuclear and mitochondrial DNA sequences were used to test a recent phylogenetic hypothesis for the avian genus Gallicolumba that relied heavily on preserved museum study skins for DNA samples. Our comparisons show that several published gene sequences represent pseudogenes or chimeras of multiple taxa, and these sequences had an adverse influence on phylogeny estimation. A new phylogenetic hypothesis strongly supports the monophyly of Philippine bleeding-hearts, the monophyly of Gallicolumba sensu stricto, and places Leucosarcia as part of an Australasian radiation rather than sister to Alopecoenas. These findings clarify Gallicolumba biogeography and also highlight the need for greater caution in the use of suboptimal source material in molecular systematic studies.     

The phylogenetic relationships of the physaloid genera (Solanaceae) based on morphological data

A group of genera, e.g., Chamaesaracha, Leucophysalis, Physaliastrum, Margaranthus, and Withania, in the subfamily Solanoideae (Solanaceae) is centered around the genus Physalis and has been named the physaloid group. It comprises a number of small and often poorly known genera, sometimes seen as united with Physalis and/or each other. A hypothesis of the phylogenetic relationships within this group, based on parsimony analyses of morphological data, is here presented for the first time. The result is discussed in relation to prevailing generic circumsciptions and taxonomic consequences. It is also compared with hypotheses of relationships based on cpDNA data.     

A re-evaluation of basal phylogenetic relationships within trogons (Aves: Trogonidae) based on nuclear DNA sequences

The avian clade Trogonidae (trogons) consists of approximately 40 species distributed pantropically in the Neotropical, Afrotropical and Indomalayan zoogeographical regions. In this study, we evaluate the basal phylogenetic relationships within the trogons based on DNA sequences from three nuclear introns [myoglobin intron 2, β -fibrinogen intron 7 and glyceraldehydes-3-phosphodehydrogenase (G3PDH) intron 11]. In addition, previously published cytochrome b and 12S sequences were re-analysed and combined with the nuclear data set. The analysis of the three nuclear genes combined suggests a sister group relationship between the Afrotropical ( Apaloderma ) and Indomalayan ( Harpactes ) clades, whereas the Neotropical taxa ( Trogon , Pharomachrus , and Priotelus ) form an unresolved polytomy basal to these two groups. In addition, two of the three individual gene trees also support a sister group relationship between the Afrotropical and Indomalayan trogons. This is at odds with previously published studies based on mitochondrial sequence data and DNA–DNA hybridization. The third nuclear intron (G3PDH), however, suggests that the Afrotropical trogons are basal relative the other trogons. This was also suggested by the mitochondrial data set, as well as the analysis of the combined nuclear and mitochondrial data. Both of these conflicting hypotheses are supported by high posterior probabilities. An insertion in β -fibrinogen further supports a basal position of the Afrotropical clade. Analyses of the myoglobin intron with additional outgroups place the root differently and strongly support monophyly of each of the zoogeographical regions (including the Neotropics), and these three clades form a basal trichotomy. This suggests that that rooting is a serious problem in resolving basal phylogenetic relationships among the trogons.     

Phylogenetic relationships of woodcreepers (Aves: Dendrocolaptinae) – incongruence between molecular and morphological data

The woodcreepers is a highly specialized lineage within the New World suboscine radiation. Most systematic studies of higher level relationships of this group rely on morphological characters, and few studies utilizing molecular data exist. In this paper, we present a molecular phylogeny of the major lineages of woodcreepers (Aves: Dendrocolaptinae), based on nucleotide sequence data from a nuclear non-coding gene region (myoglobin intron II) and a protein-coding mitochondrial gene (cytochrome b ). A good topological agreement between the individual gene trees suggests that the resulting phylogeny reflects the true evolutionary history of woodcreepers well. However, the DNA-based phylogeny conflicts with the results of a parsimony analysis of morphological characters. The topological differences mainly concern the basal branches of the trees. The morphological data places the genus Drymornis in a basal position (mainly supported by characters in the hindlimb), while our data suggests it to be derived among woodcreepers. Unlike most other woodcreepers, Drymornis is ground-adapted, as are the ovenbirds. The observed morphological similarities between Drymornis and the ovenbird outgroup may thus be explained with convergence or with reversal to an ancestral state. This observation raises the question of the use of characters associated with locomotion and feeding in phylogenetic reconstruction based on parsimony.     

New Antarctic deep-sea weird leech (Hirudinida: Piscicolidae): morphological features and phylogenetic relationships

A new fish leech Ambulobdella shandikovi n. g., n. sp. (Hirudinida: Piscicolidae), a parasite of Whitson’s grenadier Macrourus whitsoni (Regan) (Macrouridae: Gadiformes) collected in the Ross Sea at depths from 1,221 to 1,433 m, is described and compared with related taxa based on morphological and molecular characters. Ambulobdella shandikovi n. sp. is characterised by prominent segmental tubercles on the venter and dorsal segmental tubercles, an uncommon appearance of its anterior sucker with ear-like edges and an inner membrane around the mouth-pore, well-developed musculature and a unique combination of features of the reproductive and digestive systems. The presence of uncommon tubercles can be attributed, in part, to temporary associations of A. shandikovi n. sp. with its fish hosts and a need for well-developed sensory and locomotory organs. A certain locomotory function of ventrolateral tubercles of A. shandikovi n. sp. is hypothesised and discussed. Further deep-sea surveys are obviously needed to shed light on the behaviour and mode of locomotion of this species.     

Systematic relationships of the palaeogene family Presbyornithidae (Aves: Anseriformes)

The early Tertiary (Paleocene and Eocene) family Presbyornithidae is one of the most completely known group of fossil birds. Essentially all parts of the skeleton are represented in the fossil record, allowing a thorough analysis of the phylogenetic position of the family. Forty-two families of nonpasserine birds representing the orders Ciconiiformes, Anseriformes, Galliformes, Gruiformes and Charadriiformes, were included in a cladistic analysis of 71 skeletal characters. The previously suggested anseriform affinity of the Presbyornithidae was confirmed. Furthermore, the family proved to be closer to the Anatidae than to the Anhimidae or Anseranatidae. The many postcranial similarities with certain charadriiform birds as the Burhinidae, obviously are plesiomorphies. By this observation, a better undestanding of character evolution in nonpasserine skeletal morphology is gained. The often suggested close relationship of anseriform and galliform birds is not confirmed by osteology. Instead, the Anseriformes and the Phoenicopteridae form a monophyletic clade that is the sister to the remaining ciconiiform birds. This result renders the Ciconiiformes sensu Wetmore (1960) polyphyletic.     

Phylogenetic relationships of the mockingbirds and thrashers (Aves: Mimidae)

The mockingbirds, thrashers and allied birds in the family Mimidae are broadly distributed across the Americas. Many aspects of their phylogenetic history are well established, but there has been no previous phylogenetic study that included all species in this radiation. Our reconstructions based on mitochondrial and nuclear DNA sequence markers show that an early bifurcation separated the Mimidae into two clades, the first of which includes North and Middle American taxa (Melanotis, Melanoptila, Dumetella) plus a small radiation that likely occurred largely within the West Indies (Ramphocinclus, Allenia, Margarops, Cinclocerthia). The second and larger radiation includes the Toxostoma thrasher clade, along with the monotypic Sage Thrasher (Oreoscoptes) and the phenotypically diverse and broadly distributed Mimus mockingbirds. This mockingbird group is biogeographically notable for including several lineages that colonized and diverged on isolated islands, including the Socorro Mockingbird (Mimus graysoni, formerly Mimodes) and the diverse and historically important Galapagos mockingbirds (formerly Nesomimus). Our reconstructions support a sister relationship between the Galapagos mockingbird lineage and the Bahama Mockingbird (M. gundlachi) of the West Indies, rather than the Long-tailed Mockingbird (M. longicaudatus) or other species presently found on the South American mainland. Relationships within the genus Toxostoma conflict with traditional arrangements but support a tree based on a preivous mtDNA study. For instance, the southern Mexican endemic Ocellated Thrasher (T. ocellatum) is not an isolated sister species of the Curve-billed thrasher (T. curvirostre).     

Taxonomic revision and phylogenetic analysis of the flightless Mancallinae (Aves, Pan-Alcidae)

Although flightless alcids from the Miocene and Pliocene of the eastern Pacific Ocean have been known for over 100 years, there is no detailed evaluation of diversity and systematic placement of these taxa. This is the first combined analysis of morphological and molecular data to include all extant alcids, the recently extinct Great Auk Pinguinus impennis, the mancalline auks, and a large outgroup sampling of 29 additional non-alcid charadriiforms. Based on the systematic placement of Mancallinae outside of crown clade Alcidae, the clade name Pan-Alcidae is proposed to include all known alcids. An extensive review of the Mancallinae fossil record resulted in taxonomic revision of the clade, and identification of three new species. In addition to positing the first hypothesis of inter-relationships between Mancallinae species, phylogenetic results support placement of Mancallinae as the sister taxon to all other Alcidae, indicating that flightlessness evolved at least twice in the alcid lineage. Convergent osteological characteristics of Mancallinae, the flightless Great Auk, and Spheniscidae are summarized, and implications of Mancallinae diversity, radiation, and extinction in the context of paleoclimatic changes are discussed.     

A phylogenetic supertree of oscine passerine birds (Aves: Passeri)

Oscine passerine birds make up almost half of all avian diversity. Relationships within the group, and its classification, have long been controversial. Over the last 10 years numerous molecular phylogenies have been published. We compiled source phylogenies from 99 published studies to construct an oscine supertree. We aimed to illustrate weak and strong parts of the phylogeny and set targets for future phylogenetic work and therefore preferred a heuristic approach where we judged the adequacy of taxon sampling and molecular method of each source tree instead of using matrices and automated tree-building programs. We present an estimate of the phylogenetic relationships of 1723 extant and one extinct species of oscine passerine birds (Aves: Passeri) — more than 37% of the total. We included 34/35 (97%) families, 38/39 (97%) subfamilies and 40/43 (93%) tribes. Overall resolution is 83% of a fully bifurcating tree. The basal lineages are all distributed in the Australo-Papuan region, but several more distal lineages dispersed out of this region and radiated in other parts of the world. However, taxa of the Australian region suffer from larger evolutionary gaps and the deep branches of the Sylvioidea and nine South American primaried oscines are still poorly resolved.     

Evidence for a phylogenetic position of button quails (Turnicidae: Aves) among the Gruiformes

The phylogenetic position of the Turnicidae (Aves) was unresolved. Historically, they were classified as members of the Struthioniformes, Galliformes, Charadriiformes, Columbiformes or the Gruiformes. In these classifications they had taxonomic rank of order 'Turniciformes' or family 'Turnicidae'. However, most of these studies followed phenetic methodology and used morphological similarity of taxa and plesiomorphic characters to classify Turnix . Recent phylogenetic studies on the basis of morphological character analyses or phenetic comparisons based on DNA-DNA hybridization experiments failed to clarify the phylogenetic realtionship of Turnix and suggested a position as 'incerte sedis', either among the Gruiformes or as the parvclass 'Turnicac'as a sistergroup to the 'Neoaves'.
We studied skeletal and myological material of Turnix to resolve its phylogenetic position. Further, we considered all characters that were previously discussed in literature to classify Turnix and tested them for their potential use in phylogenetic analysis. We added several yet unemployed morphological characters of phylogenetic significance to the analysis. The Struthioniformes, 'Galloanseres', and Columbiformes are each characterized by a clear set of autapomorpies. Only one autapomorphy in known for the Gruiformes but this character is of satisfying consistency and can be found in all families of the Gruiformes (Gruidae, Psophiidae, Aramidae. Rallidae) and Turnix. Turnix and the Rallidae share four complex morphological characters implying a close phylogenetic relationship. The data presented in this paper support the hypothesis that Turnix is a member of the Gruiformes with close relationships to the Rallidae. No evidence was found that would support a parvclass 'Turnicae'as sistergroup to the 'Neoaves'.     

Phylogeny of the Falconidae (Aves): a comparison of the efficacy of morphological, mitochondrial, and nuclear data

We sequenced 2800+ bp of the RAG-1 exon for representatives of all the currently recognized genera in the avian family Falconidae. A phylogenetic analysis of these data was compared to prior analyses of mitochondrial (cytochrome-b) and morphological (syringeal) data. The nuclear RAG-1 sequences produced results that were in agreement with the morphological results, but differed from the mitochondrial results with regard to monophyly of the genus Micrastur. A reanalysis of the cytochrome-b (cyt-b) data suggested that this result was due to heterogeneity in base composition. Comparisons of data quality and quantity across the three data sets indicate that the nuclear DNA sequences and the morphological data have similar consistency and retention indices as well as noise distributions that are superior to those of cyt-b. However, the RAG-1 data identify more nodes with high bootstrap support indices than do either morphology or mitochondrial sequences. In the final assessment, RAG-1 sequences were superior in phylogenetic utility both to syringeal morphology (because of sheer number of characters) and to cyt-b sequences (because of reduced noise and homogeneity of base composition, but in spite of having many fewer characters).     

Toward a resolution of a taxonomic enigma: first genetic analyses of Paradoxornis webbianus and Paradoxornis alphonsianus (Aves: Paradoxornithidae) from China and Italy

Paradoxornis webbianus and Paradoxornis alphonsianus naturally occur in South-East Asia. Due to a recent introduction, a mixed population currently occurs in northern Italy. A preliminary phylogeographic analysis using samples from Italy and China found little genetic differentiation between the two taxa and revealed the existence of two molecular lineages, sympatric in some part of China, that do not correspond to the morphological classification. Possible taxonomic changes and preliminary inferences on the relationships between Chinese and the Italian populations and on the likely provenance of the founders introduced in Italy are also discussed.