Phylogenetic Framework for Trema (Celtidaceae)

We used ITS and trnL sequence data, analyzed separately and combined by MP, to explore species relationships and concepts in Trema (Celtidaceae), a pantropical genus of pioneer trees. Whether Trema is monophyletic or includes Parasponia is still unresolved. Three clades within Trema received moderate to high support, one from the New World and two from the Old World, but their relationships were not resolved. In the New World, specimens of T. micrantha formed two groups consistent with endocarp morphology. Group I, with smaller brown endocarps, is a highly supported clade sister to T. lamarckiana. Group II, with larger black endocarps, is poorly resolved with several subclades, including the highly supported T. integerrima clade. Both Old World clades contain Asian and African species, with three or more species in each region. Trema orientalis is not monophyletic: specimens from Africa formed a highly supported clade sister to T. africana, while those from Asia were sister to T. aspera from Australia.     

Nomenclatural changes in <Emphasis Type="Italic">Lithospermum</Emphasis> (Boraginaceae) and related taxa following a reassessment of phylogenetic relationships

Lithospermum (Boraginaceae) comprises approximately 40 species in both the Old and New Worlds, with a center of diversity in the southwestern United States and Mexico. Using ten cpDNA regions, a phylogeny of Lithospermum and related taxa was reconstructed. Lithospermum (including New World and Old World species) and related New World members of Lithospermeae form a monophyletic group, with Macromeria, Onosmodium, Nomosa, Lasiarrhenum, and Psilolaemus nested among species of Lithospermum. New World Lithospermeae also is a monophyletic group, with Eurasian species of Lithospermum sister to this group. Because Lithospermum is not monophyletic without the inclusion of the other New World genera, species from these genera are transferred to Lithospermum, and appropriate nomenclatural changes are made. New combinations are Lithospermum album, Lithospermum barbigerum, Lithospermum dodrantale, Lithospermum exsertum, Lithospermum helleri, Lithospemum leonotis, Lithospermum notatum, Lithospermum oaxacanum, Lithospermum pinetorum, Lithospermum rosei, Lithospermum trinverium, and Lithospermum unicum; new names are Lithospermum chiapense, Lithospermum johnstonii, Lithospermum macromeria, Lithospermum onosmodium, Lithospermum rzedowskii, and Lithospermum turneri.     

Molecular evidence for naturalness of genera in the tribe Antirrhineae (Scrophulariaceae) and three independent evolutionary lineages from the New World and the Old

The tribe Antirrhineae consists of 29 genera distributed in the New World and the Old. Phylogenetic analyses of ITS and ndhF sequences served to recognize six main lineages: Anarrhinum group (Anarrhinum, Kickxia); Linaria group (Linaria); Maurandya group (Cymbalaria, Asarina, Maurandella, Rhodochiton, Lophospermum); Schweinfurthia group (Pseudorontium, Schweinfurthia); Antirrhinum group (Antirrhinum, Pseudomisopates, Misopates, Acanthorrhinum, Howeliella, Neogarrhinum, Sairocarpus, Mohavea, Galvezia); Chaenorrhinum group (Chaenorrhinum, Albraunia, Holzneria). Parsimony (cladistics), distance-based (Neighbor-Joining), and Bayesian inference reveal that: (1) the tribe is a natural group; (2) genera such as Linaria, Schweinfurthia, Kickxia, and Antirrhinum also form natural groups; (3) three Antirrhineae lineages containing genera from the New and Old World are the result of three intercontinental disjunctions displaying similar levels of ITS-sequence divergence and differentiation times (Oligocene-Miocene); (4) evolution of flower shapes is not congruent with primitiveness of personate flowers; (5) both polyploidy and dysploidy appear to be responsible for most variation in chromosome number in the six main lineages. Nuclear and chloroplast evidence also supports the split of American and Mediterranean species of Antirrhinum into different genera, a result that should be contemplated in the interest of a more natural (monophyletic) taxonomy. Nucleotide additivity causes poor resolution in the ITS analysis of 22 species of Mediterranean Antirrhinum and lead us to interpret extensive hybridization in the Iberian Peninsula.This research was supported by the Spanish Dirección General de Investigación Científica y Técnica (DGICYT) through the project Flora Iberica (PS91-0070-C03-01). We thank Jorge Martínez and Emilio Cano for his assistance in the lab, Rafael Rubio and Omar Fiz for helping on the Bayesian inferences, the curators/collection managers of BCF, E, JACA, MA, SALA, SALAF, SEV, TARI, VAL for loans and access to specimens, and two anonymous reviewers for improving the quality of this publication.     

Molecular systematics of the Old World Astragalus (Fabaceae) as inferred from nrDNA ITS sequence data

This study represents a nuclear rDNA ITS-based phylogenetic analyses of a greater sampling of the Old WorldAstragalus compared to our previous work (212 vs. 134 taxa). Phylogenetic relationships among 212 species (213 accessions) of the Old WorldAstragalus, including newly segregated monotypic genusPodlechiella, the two aneuploid New WorldAstragalus, and five related genera, were inferred from analyses of nuclear rDNA ITS sequences using maximum parsimony. A total of 658 nucleotide sites and four binary characters for indels were analyzed. The results of phylogenetic analyses suggest sect.Phyllolobium, comprising mostly the Chinese species, is placed outside of the so-calledAstragalus s. str. and is a well-supported monophyletic group. The monotypic annual segregate genusThlaspidium (≡Astragalus sect.Thlaspidium, A. thlaspi), is clearly nested withinAstragalus s. str. Among the many sections analyzed here, only sects.Cenanthrum, Caraganella, Eremophysa, Incani, Laxiflori, andLotidium are strongly supported as monophyletic. Our analysis, in agreement with previous studies, shows that the North American euploidAstragalus species are scattered throughout the Old World groups of the genus.     

A phylogenetic analysis of the palm subtribe Oncospermatinae (Arecaceae) based on morphological characters

Subtribe Oncospermatinae (Arecaceae: Arecoideae: Areceae) is a diverse group of spiny Old World palms. The subtribe includesOncosperma, a widespread Asian genus of five species, along with seven monotypic genera, all endemic to the Seychelles and Mascarene Islands of the western Indian Ocean. A phylogenetic analysis was conducted in order to test the monophyly of subtribe Oncospermatinae with respect to other Old World genera of tribe Areceae. A matrix of 38 morphological characters was scored for 29 taxa, including 11 species of the Oncospermatinae. A single most parsimonious tree was found, resolving the subtribe as a polyphyletic group of two distinct clades. One clade containingAcanthophoenix, Deckenia, Oncosperma, andTectiphiala was placed as sister to a large group that includes members of subtribes Archontophoenicinae, Arecinae, Iguanurinae, and Ptychospermatinae. The other clade of Oncospermatinae, including the Seychelles endemic generaNephrosperma, Phoenicophorium, Roscheria, andVerschaffeltia, was resolved as sister to the Madagascar endemic subtribe Masoalinae, and may have arisen in the western Indian Ocean region.     

Marbleseeds are gromwells – Systematics and evolution of Lithospermum and allies (Boraginaceae tribe Lithospermeae) based on molecular and morphological data

Phylogenetic relationships are complex within the Lithospermeae, a large subgroup of the Boraginaceae s.str. The relationships of New World Lasiarrhenum, Macromeria, Nomosa, Onosmodium, Perittostoma, and Psilolaemus to subcosmopolitan and much larger Lithospermum have not been critically investigated in the recent past. No molecular data on the phylogeny of these genera and Lithospermum have so far been published. We investigated the relationships within Lithospermeae using three loci (nuclear ITS plus 5.8S rRNA, chloroplast trnL-F-spacer, and trnS-G-spacer) and micromorphological character traits (pollen, nutlets). Lithospermum s.l. constitutes the sistergroup of Asian Ulugbekia and is monophyletic only when its American segregates “Macromeria”, monotypic Nomosa, and Onosmodium are included. Both the African and the South American species groups of Lithospermum are monophyletic, but North American representatives are not resolved in a single clade. Morphological characters that have been considered as important for generic delimitation in the past (such as large, yellow corollas without faucal scales, particular pollen types, coarsely veined leaves, shrubby habit) have evolved in at least two only distantly related lineages within Lithospermum s.l. The reduction of American “Macromeria”, Nomosa, and Onosmodium as well as Asian Ulugbekia under Lithospermum is proposed to render the latter monophyletic. This redefined Lithospermum s.l. appears to have undergone a type of recent “island radiation” in the Americas, reflected in a morphological diversity far exceeding that found in the Old World.     

Multi-locus phylogeny clarifies the systematics of the Australo-Papuan robins (Family Petroicidae, Passeriformes)

The Australo-Papuan family Petroicidae (Aves: Passeriformes) has been the focus of much systematic debate about its relationships with other passerine families, as well as relationships within the family. Mostly conservative morphology within the group limits the effectiveness of traditional taxonomic analyses and has contributed to ongoing systematic debate. To assess relationships within the family, we sampled 47 individuals from 26 species, representing the majority of genera and species, for four loci: 528 base pairs (bp) of C-myc, 501 bp of BA20454 and 336 bp of BA23989 from nuclear DNA and 1005 bp of the mitochondrial ND2 gene. There was consensus between individual loci and overall support for major lineages was strong. Partitioned Bayesian analyses of all four loci produced a fully resolved and very well-supported phylogeny that addresses many of the previous systematic debates in this group. The Eopsaltriinae as construed is monophyletic with the exception of Eopsaltria flaviventris, which is nested within Microeca as an unremarkable member of that genus. This relationship is corroborated by morphology and egg color and pattern. Petroicinae as currently construed was not monophyletic and comprised two lineages that are paraphyletic with respect to each other. The third subfamily, Drymodinae, remains incertae sedis. The mangrove robin, Peneonanthe pulverulenta, of tropical Australia and New Guinea is nested within a clade that also contained the sampled species of Peneothello and Melanodryas, a novel relationship. Preliminary biogeographic and divergence time estimates from these results are discussed and a new subfamily arrangement proposed.     

Chloroplast DNA restriction site variation in theVernonieae (Asteraceae), an initial appraisal of the relationship of New and Old World taxa and the monophyly ofVernonia

Chloroplast DNA restriction site variation was examined for 35 taxa in theVernonieae and four outgroup tribes, using 17 restriction enzymes mapped for ca. 900 restriction sites per species; 139 mutations were found to be phylogenetically informative. Phylogenetic trees were constructed using Wagner and weighted parsimony, and evaluated by bootstrap and decay analyses. Relationships of Old and New World taxa indicate complex geographical relationships; there was no clear geographic separation by hemisphere. The relationships between Old and New World Vernonias found here support prior morphological analyses. The sister group to all New and most Old World taxa was composed of a small group of Old World species including yellow-flowered, trinervate-leaved species previously postulated to be basal in the tribe. The majority of both New and Old World taxa are derived from a lineage beginning with the monotypic genusStokesia, an endemic of the southeastern United States. The genusVernonia was also found to be paraphyletic within both the New and Old World. Available data do not support either the separation ofVernonia or the tribeVernonieae into geographically distinct lineages. The pattern of relationships within theVernonieae for taxa from North America, Asia, Africa, Central and South America is most similar to that of several other groups of both plants and animals with a boreotropical origin, rather than an origin in Gondwanaland. Such a pattern of distribution suggests more ancient vicariant events than are routinely postulated for theAsteraceae.     

Molecular systematics and biogeography of Nicrophorus in part--the investigator species group (Coleoptera: Silphidae) using mixture model MCMC

Burying beetles (Silphidae: Nicrophorus) are well-known for their biparental care and monopolization of small vertebrate carcasses in subterranean crypts. They have been the focus of intense behavioral ecological research since the 1980s yet no thorough phylogenetic estimate for the group exists. The relationships among the species, and the validity of some species, are poorly understood. Here, we infer the relationships and examine species boundaries among 50 individuals representing 15 species, primarily of the investigator species group, using a mixture-model Bayesian analysis. Two mitochondrial genes, COI and COII, were used, providing 2129 aligned nucleotides (567 parsimony-informative). The Akaike Information Criterion and Bayes Factors were used to select the best fitting model, in addition to Reversible Jump MCMC, which accommodated model uncertainty. A 21 parameter, three-partition GTR + G was the final model chosen. Despite a presumed Old World origin for the genus itself, the basal lineages and immediate outgroups of the investigator species group are New World species. Bayesian methods reconstruct the common ancestor of the investigator species group as New World and imply one later transition to the Old World with two return transitions to the New World. Prior hypotheses concerning the questionable validity of four species names, Nicrophorus praedator, Nicrophorus confusus, Nicrophorus encaustus and Nicrophorus mexicanus were tested. No evidence was found for the validity of the Nicrophorus investigator synonym N. praedator. We found evidence rejecting the species status of N. confusus (NEW SYNONYM of Nicrophorus sepultor). Weak evidence was found for the species status of N. encaustus and N. mexicanus, which are tentatively retained as valid. Our results strongly reject a recently published hypothesis that Nicrophorus interruptus (NEW STATUS as valid species) is a subspecies of N. investigator.     

Cuticular Extracts of Five Common Mantids (Mantodea: Mantidae) of the Eastern United States

We undertook a preliminary investigation of the cuticular extracts of five common mantid species in the eastern United States: Tenodera sinensis (Saussure), T. angustipennis (Saussure) and Mantis religiosa (Linnaeus) introduced from the Old World and Stagmomantis carolina (Johannson) and Bruneria borealis (Scudder), which are New World species. The major components of these mixtures were normal alkanes, predominately hentriacontane, or in the case of the parthenogenic species B. borealis, tritriacontane. Tricontanal was detected in the extracts of all five species, and smaller amounts of other aldehydes and n-tricontanol were detected in some species. Complex mixtures of methyl and dimethylalkanes also were present in these extracts. The composition of the cuticular hydrocarbons of these mantids may be an adaptation for reduction of evaporative water loss in these insects that inhabit open fields.     

Molecular phylogeny, diversification and character evolution in Lupinus (Fabaceae) with special attention to Mediterranean and African lupines

Phylogenetic relationships within the complex genus Lupinus are estimated from internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA repeat. The molecular data supports Lupinus as a distinct monophyletic group within the tribe Genisteae. Different geographical lineages are revealed within Lupinus, which are each restricted to either the Old or the New World. In the New World, the ITS data support an eastern-western geographic disjunction of the lupines and the recognition of some well-supported clades. In the Old World, almost all the previously recognized taxa are taxonomically well differentiated. The homogeneous African rough-seeded lupines, Scabrispermae, are strongly supported as a monophyletic group, which is distinct from the diverse and heterogeneous circum-Mediterranean smooth-seeded ones. The latter appear to have evolved as two lineages, in which are revealed some intersectional relationships. Also ITS data allow the assessment of the phylogenetic position of the newly discovered species, L. anatolicus (in the Old World) and L. jaimehintoniana (the Mexican tree lupin). The ITS phylogeny suggests a rapid initial radiation of the lupines subsequent to their divergence from a common ancestor. Moreover, the results indicate that the annual and perennial habits have evolved many times in Lupinus and suggest a role for generation time in affecting the evolutionary history of lupines. Data on adaptive processes and character evolution are re-examined and discussed in the light of the ITS phylogeny.These studies were supported by the research unit UMR-CNRS 6553 Ecobio – University of Rennes (France), and by the NSERC of Canada (grant to R.J. Bayer, at the University of Alberta). They are greatfully acknowledged. All the persons that have contributed in different ways to this work on Lupinus, summarized in this presentation, are greatly thanked. Particularly, we would like to mention Malika Aïnouche, Roland Greinwald, André Huon, W.K. Swiecicki, Billie L. Turner and Ludger Witte for their contributions.     

Phylogenetic relationships and taxonomy of subfamily Zygophylloideae (Zygophyllaceae) based on molecular and morphological data

Phylogenetic analysis of noncoding trnL plastid DNA sequences and morphological data for 43 species of Zygophylloideae, representing most of the morphological and geographical variation in the subfamily, indicates that the currently recognised genera Augea (monotypic, southern Africa), Tetraena (monotypic, China), and Fagonia (c. 30 species, widespread), are embedded in Zygophyllum (c. 150 species, widespread). A generic classification based on six monophyletic and morphologically distinctive entities is proposed: Roepera with c. 60 species in Australia and southern Africa, Zygophyllum with c. 50 species in Asia, Tetraena with c. 40 species in Africa and Asia, Augea with a single species in southern Africa, Melocarpum with two species in the Horn of Africa region, and Fagonia with c. 30 species in both the Old and the New World. Scanning electron microscopy studies of testa structure provided important characters for the delimitation of some genera. New combinations (61) are made in Roepera, a resurrected genus originally described from Australia, one new name is proposed in Zygophyllum, 35 new combinations are made in Tetraena, and two new combinations are made in Melocarpum (previously Zygophyllum sect. Melocarpum).     

Historical biogeography and character evolution of Cistaceae (Malvales) based on analysis of plastid rbcL and trnL-trnF sequences

Cistaceae consist of eight genera and about 180 species. Some taxonomic limits and relationships within the family remain unresolved when relying exclusively on morphological data. In the present study, a phylogeny was reconstructed and divergence times were estimated for 47 species representing various groups in Cistaceae and using coding (rbcL) and spacer (trnL-trnF) sequences of plastid DNA. The firm set of morphological synapomorphies that indicates the monophyly of the family is supported by both Bayesian and parsimony analyses. Five major lineages can be distinguished within the Cistaceae: (1) an early-diverging lineage containing Fumana species; (2) the New World Lechea clade; (3) the Helianthemum s.l. clade, containing two sister groups, one of species from the New World (Crocanthemum, Hudsonia) and the other with species from the Old World (Helianthemum s. str.); (4) the Tuberaria clade; and (5) a cohesive complex consisting of Halimium and Cistus species. Evolutionary shifts in 12 key characters of Cistaceae are inferred based on the most plausible phylogenetic hypothesis. Reconstructing the evolution of ovule position supports anatropous ovules as the ancestral condition within the Cistaceae, which is currently found only in Fumana. The Cistus-Halimium assemblage is consistently obtained as a natural clade and further supported by a cytological synapomorphy (chromosome number n=9). Optimisation of ancestral distribution areas and estimates of divergence times reveal an early divergence (10.17-18.51 Ma) of the Mediterranean-European genera, which may be related to subtropical vegetation, as complemented by paleobotanical data. In addition, the occurrence of multiple, independent migration events from the Old World to America between the Middle Miocene (8.44-14.7 Ma; Lechea) and the Upper Miocene (5.15-9.20 Ma; Crocanthemum/Hudsonia), and to the Canary Islands in the Pleistocene is inferred. We argue that the Mediterranean basin has been the main centre of differentiation of Cistaceae.     

Phylogenetic relationships among species and genera of Lycoperdaceae based on ITS and LSU sequence data from north European taxa

Phylogenetic relationships, limits of species, and genera within Lycoperdaceae, were inferred by use of ITS and LSU nu-rDNA sequence data. Lycoperdaceae was confirmed as monophyletic, and Mycenastrum corium as a sister taxon to the ingroup. Four major clades were identified and received weak to moderate support and correspond with the genera Lycoperdon, Bovista, Calvatia, and Disciseda. The Lycoperdon clade includes species from Lycoperdon, Vascellum, Morganella, Handkea, Bovistella, and Calvatia. The structure within the Lycoperdon clade is unresolved and several clades are more or less unsupported, which suggests treating the supported Lycoperdon clade as the genus Lycoperdon. L. nigrescens and L. caudatum occur on single branches and their phylogenetic positions could not be resolved. The phylogenetic analyses identified 31 species of Lycoperdon, 11 species of Bovista, six species of Calvatia, and two species of Disciseda. In Lycoperdon three new species were recognized. A new species closely related to B. limosa is identified and discussed. A classification of Lycoperdaceae is proposed based on the results of the phylogenetic analyses. Morphological characters of species within and among identified clades are discussed.     

A new Indo-Malayan member of the Stenostiridae (Aves: Passeriformes) revealed by multilocus sequence data: Biogeographical implications for a morphologically diverse clade of flycatchers

Recent molecular studies on passerine birds have highlighted numerous discrepancies between traditional classification and the phylogenetic relationships recovered from sequence data. Among the traditional families that were shown to be highly polyphyletic are the Muscicapidae Old World flycatcher. This family formerly included all Old World passerines that forage on small insects by performing short sallies from a perch. Genera previously allocated to the Muscicapidae are now thought to belong to at least seven unrelated lineages. While the peculiarity of most of these lineages has been previously recognized by Linnean classification, usually at the rank of families, one, the so-called Stenostiridae, a clade comprising three Afrotropical and Indo-Malayan genera, has only recently been discovered. Here, we address in greater detail the phylogenetic relationships and biogeographic history of the Stenostiridae using a combination of mitochondrial and nuclear data. Our analyses revealed that one species, Rhipidura hypoxantha, previously attributed to the Rhipiduridae (fantails), is in fact a member of the Stenostiridae radiation and sister to the South African endemic genus Stenostira (Fairy Flycatcher). Our dating analyses, performed in a relative-time framework, suggest that the splits between Stenostira/R. hypoxantha and Culicicapa/Elminia occurred synchronously. Given that the Stenostiridae assemblage has been consistently recovered by independent studies, we clarify its taxonomic validity under the rules of the International Code of Zoological Nomenclature.     

Phylogeny of the tribe Antirrhineae (Scrophulariaceae) based on morphological andndhF sequence data

Phylogenetic relationships within the tribe Antirrhineae (Scrophulariaceae) are analysed and discussed on the basis of parsimony analyses of morphological andndhF gene sequence data. The results indicate that the tribe Antirrhineae consists of four major groups of genera, theAnarrhinum clade, theGambelia clade, theMaurandya clade, and theAntirrhinum clade. TheAnarrhinum clade, consisting of the Old World bee-pollinated generaAnarrhinum andKickxia, is sister to the rest of the tribe. TheGambelia clade consists of the New World generaGambelia andGalvezia, which are very closely related and pollinated by hummingbirds. TheMaurandya clade consists of one subclade includingMaurandya and a number of related bee- or hummingbird-pollinated New World genera and another subclade with the Old World bee-pollinated generaAsarina andCymbalaria. TheAntirrhinum clade consists mainly of bee-pollinated Old World genera, such asAntirrhinum, Linaria, Chaenorhinum, and their segregates, but also includes the New World generaMohavea andHowelliella, of which the latter is known to be partly pollinated by hummingbirds. It is concluded that hummingbirdpollination has evolved independently within Antirrhineae at least three times from bee-pollinated ancestors.     

Longevity of multiple species of tephritid (Diptera) fruit fly parasitoids (Hymenoptera: Braconidae: Opiinae) provided exotic and sympatric-fruit based diets

While adult parasitic Hymenoptera in general feed on floral and extrafloral nectars, hemipteran-honeydews and fluids from punctured hosts, Diachasmimorpha longicaudata (Ashmead), an Old World opiine braconid introduced to tropical/subtropical America for the biological control of Anastrepha spp. (Tephritidae), can survive on fruit juices as they seep from injured fruit. An ability to exploit fruit juice would allow such a parasitoid to efficiently forage for hosts and food sources simultaneously. Two New World opiines, Doryctobracon areolatus (Szepligeti) and Utetes anastrephae (Viereck), are also prominent Anastrepha parasitoids and are roughly sympatric. All three species were provided with: (1) pulp and juice diets derived from a highly domesticated Old World fruit (orange, Citrus sinensis L.) that is only recently sympatric with the Mexican flies and parasitoids and so offered little opportunity for the evolution of feeding-adaptations and (2) a less-domesticated New World fruit (guava, Psidium guajava L.), sympatric over evolutionary time with D. areolatus and U. anastrephae. Both sexes of D. longicaudata died when provided guava pulp or juice at a rate similar to a water-only control. D. areolatus and U. anastrephae, presumably adapted to the nutrient/chemical constituents of guava, also died at a similar rate. Survival of all three species on orange pulp and juice was greater than on water, and often equaled that obtained on a honey and water solution. In confirmatory experiments in Mexico, D. areolatus and U. anastrephae, as well as other tephritid parasitoids Doryctobracon crawfordi (Viereck) and Opius hirtus (Fisher), all died at a significantly higher rates when provided guava in comparison to a honey and water diet. Such a result is likely due to guavas being repellent, innutritious or toxic. D. longicaudata clearly consumed guava juice tagged with a colored dye. Dilutions of orange and guava juice resulted in shorter lifespans than dilutions of orange juice and water demonstrating that there while diluted orange juice provided nutrition the addition of guava created toxicity. Given the differences in fruit-food quality, adult opiine food sources would not be obtainable at all oviposition sites and in the case of guava, more additional sites and foraging for food than previously postulated may be required.     

A mitochondrial DNA based phylogeny of weakfish species of the Cynoscion group (Pisces: Sciaenidae)

We infer the phylogeny of fishes in the New World Cynoscion group (Cynoscion, Isopisthus, Macrodon, Atractoscion, Plagioscion) using 1603 bp of DNA sequence data from three mitochondrial genes. With the exception of Plagioscion, whose position was ambiguous, the Cynoscion group is monophyletic. However, several genera examined are not monophyletic. Atlantic and Pacific species of Cynoscion are interspersed in the tree and geminate species pairs are identified. Intergeneric relationships in the group are clarified. Our analysis is the first comprehensive phylogeny for the Cynoscion group based on molecular data and provides a baseline for future comparative studies of this important group.     

Diagnosis and phylogeny of the new world streptocephalidae (Branchiopoda: Anostraca)

We present an updated diagnosis of 13Streptocephalus species of North America. Three new species are included. A key to the species is provided.The phylogeny of the group is discussed on the basis of (1) a systematic approach (Maeda-Martinezet al., 1995; this volume), which considers the entire distal antennal outgrowth, the frontal appendage, and the morphology of the ovaries as essential in defining different genetic lineages or species-groups, and (2) a cladistic analysis. We suggest that of nine monophyletic groups, three are represented in both the Old and New World. Thus, contrary to former disparsalist hypotheses, we argue that the New World species represent relict forms of ancestral groups fragmented by continental drift (vicariance model).