Phylogenetic relationships within Adiaphanida (phylum Platyhelminthes) and the status of the crustacean‐parasitic genus Genostoma

The existence of the platyhelminth clade Adiaphanida—an assemblage comprising the well‐studied order Tricladida as well as two lesser known taxa, Prolecithophora and the obligate parasitic Fecampiida—is among the more surprising results of flatworm molecular systematics. Each of these three clades is itself largely well‐defined from a morphological point of view, although Adiaphanida at large, despite its strong support in molecular phylogenetic analyses, lacks known morphological synapomorphies. However, one taxon, the genus Genostoma, a parasite of the leptostracan crustacean Nebalia, rests uneasily within its current classification within the fecampiid family Genostomatidae; ultrastructural investigations on this taxon have uncovered a spermatogenesis reminiscent of Kalyptorhynchia, and a dorsal syncytium resembling the neodermatan tegument. Here, we provide molecular sequence data (nearly complete 18S and 28S rRNA) from a representative of Genostoma, with which we test hypotheses on the phylogenetic position of this taxon within Platyhelminthes, expanding upon a recently published phylum‐wide analysis, and applying novel alignment algorithms and substitution models. These analyses unequivocally position Genostoma as the sister group of Prolecithophora. However, even in taxon‐rich analyses, support for the position of the root of Adiaphanida is lacking, highlighting the need for new data types to study the phylogeny of this clade. Interestingly, our analyses also do not recover the monophyly of several taxa previously proposed, notably Continenticola within Tricladida and Protomonotresidae within Prolecithophora. In light of this phylogeny and the distinctive morphology (especially, spermatogenesis) of Genostoma, we advocate for a redefinition of the family Genostomatidae, outside of both Fecampiida and Prolecithophora, to encompass the members of this unique genus of parasites. Within Fecampiida, the family Piscinquilinidae fam. nov. is erected to accommodate the vertebrate‐parasitic Piscinquilinus, formerly Genostomatidae.     

PHYLOGENY OF THE EUGLENALES BASED UPON COMBINED SSU AND LSU RDNA SEQUENCE COMPARISONS AND DESCRIPTION OF DISCOPLASTIS GEN. NOV. (EUGLENOPHYTA)1

A Bayesian analysis, utilizing a combined data set developed from the small subunit (SSU) and large subunit (LSU) rDNA gene sequences, was used to resolve relationships and clarify generic boundaries among 84 strains of plastid‐containing euglenophytes representing 11 genera. The analysis produced a tree with three major clades: a Phacus and Lepocinlis clade, a Discoplastis clade, and a Euglena, Colacium, Trachelomonas, Strombomonas, Monomorphina, and Cryptoglena clade. The majority of the species in the genus Euglena formed a well‐supported clade, but two species formed a separate clade near the base of the tree. A new genus, Discoplastis, was erected to accommodate these taxa, thus making the genus Euglena monophyletic. The analysis also supported the monophyly of Colacium, Trachelomonas, Strombomonas, Monomorphina, and Cryptoglena, which formed two subclades sister to the Euglena clade. Colacium, Trachelomonas, and Strombomonas, all of which produce copious amounts of mucilage to form loricas or mucilaginous stalks, formed a well‐supported lineage. Our analysis supported retaining Strombomonas and Trachelomonas as separate genera. Monomorphina and Cryptoglena formed two well‐supported clades that were sister to the Colacium, Trachelomonas, and Strombomonas clade. Phacus and Lepocinclis, both of which have numerous small discoid chloroplasts without pyrenoids and lack peristaltic euglenoid movement (metaboly), formed a well‐supported monophyletic lineage that was sister to the larger Euglena through Cryptoglena containing clade. This study demonstrated that increased taxon sampling, multiple genes, and combined data sets provided increased support for internal nodes on the euglenoid phylogenetic tree and resolved relationships among the major genera in the photosynthetic euglenoid lineage.     

Phylogenetic position of gastrostomobdellid leeches (Hirudinida,Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella

Nakano, T., Ramlah, Z. & Hikida, T. (2012). Phylogenetic position of gastrostomobdellid leeches (Hirudinida, Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella. —Zoologica Scripta, 41, 177–185. The leech family Gastrostomobdellidae is characterized by its possession of an agnathous and euthylaematous pharynx, a ventral gastropore and a gastroporal duct. In this study, the phylogenetic position of two gastrostomobdellid genera, Gastrostomobdella and Orobdella, was investigated using partial nucleic 18S, 28S rDNA and mitochondrial 12S rDNA sequences. Our phylogenetic analyses showed that both Gastrostomobdella and Orobdella are nested within Erpobdelliformes, but Gastrostomobdellidae is not a monophyletic taxon. Orobdella is a sister taxon of the other Erpobdelliformes taxa. The phylogenetic position of Gastrostomobdella within the clade of Gastrostomobdella, Erpobdellidae and Salifidae still remains uncertain. According to the reconstruction of the ancestral state of the pharynx in Erpobdelliformes, a euthylaematous pharynx is considered to be plesiomorphic in this taxon. Examination of Gastrostomobdella and Orobdella specimens indicates that the morphology of the gastroporal duct of Orobdella is quite different from that of Gastrostomobdella. A new family, Orobdellidae fam. nov., was therefore erected for the genus Orobdella. Orobdellidae is characterized by its possession of a generally tubular gastroporal duct, lying on the female organ.     

Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms

Titanosauriforms represent a diverse and globally distributed clade of neosauropod dinosaurs, but their inter‐relationships remain poorly understood. Here we redescribe Lusotitan atalaiensis from the Late Jurassic Lourinhã Formation of Portugal, a taxon previously referred to Brachiosaurus. The lectotype includes cervical, dorsal, and caudal vertebrae, and elements from the forelimb, hindlimb, and pelvic girdle. Lusotitan is a valid taxon and can be diagnosed by six autapomorphies, including the presence of elongate postzygapophyses that project well beyond the posterior margin of the neural arch in anterior‐to‐middle caudal vertebrae. A new phylogenetic analysis, focused on elucidating the evolutionary relationships of basal titanosauriforms, is presented, comprising 63 taxa scored for 279 characters. Many of these characters are heavily revised or novel to our study, and a number of ingroup taxa have never previously been incorporated into a phylogenetic analysis. We treated quantitative characters as discrete and continuous data in two parallel analyses, and explored the effect of implied weighting. Although we recovered monophyletic brachiosaurid and somphospondylan sister clades within Titanosauriformes, their compositions were affected by alternative treatments of quantitative data and, especially, by the weighting of such data. This suggests that the treatment of quantitative data is important and the wrong decisions might lead to incorrect tree topologies. In particular, the diversity of Titanosauria was greatly increased by the use of implied weights. Our results support the generic separation of the contemporaneous taxa Brachiosaurus, Giraffatitan, and Lusotitan, with the latter recovered as either a brachiosaurid or the sister taxon to Titanosauriformes. Although Janenschia was recovered as a basal macronarian, outside Titanosauria, the sympatric Australodocus provides body fossil evidence for the pre‐Cretaceous origin of titanosaurs. We recovered evidence for a sauropod with close affinities to the Chinese taxon Mamenchisaurus in the Late Jurassic Tendaguru beds of Africa, and present new information demonstrating the wider distribution of caudal pneumaticity within Titanosauria. The earliest known titanosauriform body fossils are from the late Oxfordian (Late Jurassic), although trackway evidence indicates a Middle Jurassic origin. Diversity increased throughout the Late Jurassic, and titanosauriforms did not undergo a severe extinction across the Jurassic/Cretaceous boundary, in contrast to diplodocids and non‐neosauropods. Titanosauriform diversity increased in the Barremian and Aptian–Albian as a result of radiations of derived somphospondylans and lithostrotians, respectively, but there was a severe drop (up to 40%) in species numbers at, or near, the Albian/Cenomanian boundary, representing a faunal turnover whereby basal titanosauriforms were replaced by derived titanosaurs, although this transition occurred in a spatiotemporally staggered fashion. © 2013 The Linnean Society of London     

The deep divergences of neornithine birds: a phylogenetic analysis of morphological characters

Consensus is elusive regarding the phylogenetic relationships among neornithine (crown clade) birds. The ongoing debate over their deep divergences is despite recent increases in available molecular sequence data and the publication of several larger morphological data sets. In the present study, the phylogenetic relationships among 43 neornithine higher taxa are addressed using a data set of 148 osteological and soft tissue characters, which is one of the largest to date. The Mesozoic non‐neornithine birds Apsaravis, Hesperornis, and Ichthyornis are used as outgroup taxa for this analysis. Thus, for the first time, a broad array of morphological characters (including both cranial and postcranial characters) are analyzed for an ingroup densely sampling Neornithes, with crown clade outgroups used to polarize these characters. The strict consensus cladogram of two most parsimonious trees resultant from 1000 replicate heuristic searches (random stepwise addition, tree‐bisection‐reconnection) recovered several previously identified clades; the at‐one‐time contentious clades Galloanseres (waterfowl, fowl, and allies) and Palaeognathae were supported. Most notably, our analysis recovered monophyly of Neoaves, i.e., all neognathous birds to the exclusion of the Galloanseres, although this clade was weakly supported. The recently proposed sister taxon relationship between Steatornithidae (oilbird) and Trogonidae (trogons) was recovered. The traditional taxon “Falconiformes” (Cathartidae, Sagittariidae, Accipitridae, and Falconidae) was not found to be monophyletic, as Strigiformes (owls) are placed as the sister taxon of (Falconidae + Accipitridae). Monophyly of the traditional “Gruiformes” (cranes and allies) and ”Ciconiiformes” (storks and allies) was also not recovered. The primary analysis resulted in support for a sister group relationship between Gaviidae (loons) and Podicipedidae (grebes)—foot‐propelled diving birds that share many features of the pelvis and hind limb. Exclusion of Gaviidae and reanalysis of the data set, however, recovered the sister group relationship between Phoenicopteridae (flamingos) and grebes recently proposed from molecular sequence data.     

The systematics of right whales (Mysticeti: Balaenidae)

Balaenidae (right whales) are large, critically endangered baleen whales represented by four living species. The evolutionary relationships of balaenids are poorly known, with the number of genera, relationships to fossil taxa, and position within Mysticeti in contention. This study employs a comprehensive set of morphological characters to address aspects of balaenid phylogeny. A sister‐group relationship between neobalaenids and balaenids is strongly supported, although this conflicts with molecular evidence, which may be an artifact of long‐branch attraction (LBA). Monophyly of Balaenidae is supported, and three major clades are recognized: (1) extinct genus Balaenula, (2) extant and extinct species of the genus Eubalaena, and (3) extant and extinct species of the genus Balaena plus the extinct taxon, Balaenella. The relationships of these clades to one another, as well as to the early Miocene stem balaenid, Morenocetus parvus, remain unresolved. Pliocene taxa, Balaenula astensis and Balaenula balaenopsis, form a clade that is the sister group to the Japanese Pliocene Balaenula sp. Eubalaena glacialis and Pliocene Eubalaena belgica, are in an unresolved polytomy with a clade including E. japonica and E. australis. Extant and fossil species of Balaena form a monophyletic group that is sister group to the Dutch Pliocene Balaenella, although phylogenetic relationships within Balaena remain unresolved.     

Molecular phylogeny confirms Conochilidae as ingroup of Flosculariidae (Rotifera,Gnesiotrocha)

We test the hypothesis that conochilid rotifers represent an independent family‐level taxon within Superorder Gnesiotrocha, by analysing their phylogenetic position based on the 18S rDNA sequence of a large number of representatives of this taxon and its putative relatives. Both Bayesian and maximum likelihood analysis confirm a monophyletic clade of all gnesiotrochans with strong branch supports. Within Gnesiotrocha, Conochilidae form a strongly supported clade with representatives of all but some genera of Flosculariidae. These results refute Conochilidae as separate family‐level taxon within Gnesiotrocha. This finding is also supported by a phylogenetic analysis using morphology, in particular new observations on trophi morphology. Conochilid rotifers are likely specialized Flosculariidae, which evolved to a planktonic lifestyle and reduction of coloniality within the group, in contrast to other Flosculariidae. Furthermore, our analysis reveals that two genera of Flosculariidae, Beachampia and Limnias, form a single, strongly supported clade in a sister‐group relation to a clade consisting of representatives of Order Collothecacea. The present results, both regarding position of the conochild rotifers and of two genera of Flosculariidae, highlight the need for a more extensive analysis of relationships within Gnesiotrocha.     

Morphology-based phylogeny of the treehopper family Membracidae (Hemiptera: Cicadomorpha: Membracoidea)

A parsimony‐based phylogenetic analysis of eighty‐three morphological characters of adults and immatures of seventy representatives of the tribes and subfamilies of Membracidae and two outgroup taxa was conducted to evaluate the status and relationships of these taxa. Centrotinae apparently gave rise to Nessorhinini and Oxyrhachini (both formerly treated as subfamilies, now syn.n. and syn.reinst., respectively, of Centrotinae). In contrast to previous analyses, a clade comprising Nicomiinae, Centronodinae, Centrodontinae, and the unplaced genera Holdgatiella Evans, Euwalkeria Goding and Antillotolania Ramos was recovered, but relationships within this clade were not well resolved. Nodonica bispinigera, gen.n. and sp.n., is described and placed in Centrodontini based on its sister‐group relationship to a clade comprising previously described genera of this tribe. Membracinae and Heteronotinae were consistently monophyletic. Neither Darninae nor Smiliinae, as previously defined, was monophyletic on the maximally parsimonious cladograms, but constraining both as monophyletic groups required only one additional step. The monophyly of Stegaspidinae, including Deiroderes Ramos (unplaced in Membracidae), was supported on some but not all equally parsimonious cladograms. More detailed analyses of individual subfamilies, as well as morphological data on the undescribed immatures of several membracid tribes and genera, will be needed to elucidate relationships among tribes and genera. A key to the subfamilies and tribes is provided.     

The systematic position of Meruidae (Coleoptera, Adephaga) and the phylogeny of the smaller aquatic adephagan beetle families

A phylogenetic analysis of Adephaga is presented. It is based on 148 morphological characters of adults and larvae and focussed on a placement of the recently described Meruidae, and the genus‐level phylogeny of the smaller aquatic families Gyrinidae, Haliplidae and Noteridae. We found a sister group relationship between Gyrinidae and the remaining adephagan families, as was found in previous studies using morphology. Haliplidae are either the sister group of Dytiscoidea or the sister group of a clade comprising Geadephaga and the dytiscoid families. Trachypachidae was placed as the sister group of the rhysodid‐carabid clade or of Dytiscoidea. The monophyly of Dytiscoidea including Meru is well supported. Autapomorphies are the extensive metathoracic intercoxal septum, the origin of the metafurca from this structure, the loss of Mm. furcacoxalis anterior and posterior, and possibly the presence of an elongated subcubital setal binding patch. Meruidae was placed as sister group of the Noteridae. Synapomorphies are the absence of the transverse ridge of the metaventrite, the fusion of abdominal segments III and IV, the shape of the strongly asymmetric parameres, and the enlargement of antennomeres 5, 7 and 9. The Meru‐noterid clade is the sister group of the remaining Dytiscoidea. The exact position of Aspidytes within this clade remains ambiguous: it is either the sister group of Amphizoidae or the sister group of a clade comprising this family and Hygrobiidae + Dytiscidae. The sister group relationship between Spanglerogyrinae and Gyrininae was strongly supported. The two included genera of Gyrinini form a clade, and Enhydrini are the sister group of a monophylum comprising the remaining Enhydrini and Orectochilini. A branching pattern (Peltodytes + (Brychius + Haliplus)) within Haliplidae was confirmed. Algophilus, Apteraliplus and the Haliplus‐subgenus Liaphlus form a clade. The generic status of the two former taxa is unjustified. The Phreatodytinae are the sister group of Noterinae, and Notomicrus (+ Speonoterus), Hydrocoptus, and Pronoterus branch off successively within this subfamily. The search for the larvae of Meru and a combined analysis of morphological and molecular data should have high priority. © The Willi Hennig Society 2006.     

New information on Bobosaurus forojuliensis (Reptilia: Sauropterygia): implications for plesiosaurian evolution

Preparation of the holotype specimen of Bobosaurus forojuliensis, a large sauropterygian from the lower Carnian of northeastern Italy, revealed new morphological data relevant in establishing its phylogenetic affinities among pistosauroid taxa and its relationships with plesiosaurians. Inclusion of B. forojuliensis in two phylogenetic analyses focusing, respectively, on sauropterygians and pistosauroids agreed in placing the Italian taxon as closer to plesiosaurians than to other pistosauroids. The phylogenetic interpretation of Bobosaurus was not biased by assumptions on character weighting, is consistent with its relatively younger age compared to most pistosauroids, extends the fossil record of the plesiosaurian basal lineage back to the Carnian and supports the earliest diversification of the clade during the Late Triassic in agreement with the record of several distinct lineages of rhomaleosaurids, plesiosauroids and pliosauroids in the lowermost Jurassic. Bobosaurus shows that the evolution of the plesiosaurian body plan from the ancestral pistosauroid grade was a step-wise process, and that some of the vertebral and appendicular specialisations of Jurassic and Cretaceous plesiosaurians had already developed in the earliest Late Triassic.     

The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda

The phylogenetic position of aglaspidids, a problematic group of Lower Palaeozoic arthropods of undetermined affinities, is re‐examined in the context of the major Cambrian and Ordovician lamellipedian arthropod groups. A cladistic analysis of ten genera of aglaspidids sensu stricto, six aglaspidid‐like arthropods and 42 Palaeozoic arthropod taxa indicates that Xenopoda, Cheloniellida, Aglaspidida sensu lato and Trilobitomorpha form a clade (Artiopoda Hou and Bergström, 1997 ) nested within the mandibulate stem‐lineage, thus discarding previous interpretations of these taxa as part 'of the chelicerate stem‐group (Arachnomorpha Heider, 1913 ). The results confirm an aglaspidid identity for several recently described arthropods, including Quasimodaspis brentsae, Tremaglaspis unite, Chlupacaris dubia, Australaglaspis stonyensis and an unnamed Ordovician Chinese arthropod. The problematic Bohemian arthropod Kodymirus vagans was recovered as sister taxon to Beckwithia typa, and both form a small clade that falls outside Aglaspidida sensu stricto, thus discarding eurypterid affinities for the former. The analysis does not support the phylogenetic position of Kwanyinaspis maotianshanensis at the base of Conciliterga as proposed in recent studies, but rather occupies a basal position within Aglaspidida sensu lato. The results indicate a close association of aglaspidid arthropods with xenopods (i.e. Emeraldella and Sidneyia) and cheloniellids (e.g. Cheloniellon, Duslia); the new clade “Vicissicaudata” is proposed to encompass these arthropods, which are characterized by a differentiated posterior region. The phylogenetic position of aglaspidid arthropods makes them good outgroup candidates for analysing the internal relationships within the groups that form Trilobitomorpha. This work provides a much clearer picture of the phylogenetic relationships among Lower Palaeozoic lamellipedians.     

Phylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs

The metazoan taxon Syndermata (Monogononta, Bdelloidea, Seisonidea, Acanthocephala) comprises species with vastly different lifestyles. The focus of this study is on the phylogeny within the syndermatan subtaxon Acanthocephala (thorny-headed worms, obligate endoparasites). In order to investigate the controversially discussed phylogenetic relationships of acanthocephalan subtaxa we have sequenced the mitochondrial (mt) genomes of Echinorhynchus truttae (Palaeacanthocephala), Paratenuisentis ambiguus (Eoacanthocephala), Macracanthorhynchus hirudinaceus (Archiacanthocephala), and Philodina citrina (Bdelloidea). In doing so, we present the largest molecular phylogenetic dataset so far for this question comprising all major subgroups of Acanthocephala. Alongside with publicly available mt genome data of four additional syndermatans as well as 18 other lophotrochozoan (spiralian) taxa and one outgroup representative, the derived protein-coding sequences were used for Maximum Likelihood as well as Bayesian phylogenetic analyses. We achieved entirely congruent results, whereupon monophyletic Archiacanthocephala represent the sister taxon of a clade comprising Eoacanthocephala and monophyletic Palaeacanthocephala (Echinorhynchida). This topology suggests the secondary loss of lateral sensory organs (sensory pores) within Palaeacanthocephala and is further in line with the emergence of apical sensory organs in the stem lineage of Archiacanthocephala.     

Phylogeny and classification of Cucujoidea and the recognition of a new superfamily Coccinelloidea (Coleoptera: Cucujiformia)

A large‐scale phylogenetic study is presented for Cucujoidea (Coleoptera), a diverse superfamily of beetles that historically has been taxonomically difficult. This study is the most comprehensive analysis of cucujoid taxa to date, with DNA sequence data sampled from eight genes (four nuclear, four mitochondrial) for 384 coleopteran taxa, including exemplars of 35 (of 37) families and 289 genera of Cucujoidea. Maximum‐likelihood analyses of these data present many significant relationships, some proposed previously and some novel. Tenebrionoidea and Lymexyloidea are recovered together and Cleroidea forms the sister group to this clade. Chrysomeloidea and Curculionoidea are recovered as sister taxa and this clade (Phytophaga) forms the sister group to the core Cucujoidea (Cucujoidea s.n .). The nitidulid series is recovered as the earliest‐diverging core cucujoid lineage, although the earliest divergences among core Cucujoidea are only weakly supported. The cerylonid series (CS) is recovered as monophyletic and is supported as a major Cucujiform clade, sister group to the remaining superfamilies of Cucujiformia. Currently recognized taxa that were not recovered as monophyletic include Cucujoidea, Endomychidae, Cerylonidae and Bothrideridae. Biphyllidae and Byturidae were recovered in Cleroidea. The remaining Cucujoidea were recovered in two disparate major clades: one comprising the nitidulid series + erotylid series + Boganiidae and Hobartiidae + cucujid series, and the other comprising the cerylonid series. Propalticidae are recovered within Laemophloeidae. The cerylonid series includes two major clades, the bothriderid group and the coccinellid group. Akalyptoischiidae are recovered as a separate clade from Latridiidae. Eupsilobiinae are recovered as the sister taxon to Coccinellidae. In light of these findings, many formal changes to cucujiform beetle classification are proposed. Biphyllidae and Byturidae are transferred to Cleroidea. The cerylonid series is formally recognized as a new superfamily, Coccinelloidea stat.n. Current subfamilies elevated (or re‐elevated) to family status include: Murmidiidae stat.n. , Teredidae stat.n. , Euxestidae stat.n. , Anamorphidae stat.rev. , Eupsilobiidae stat.n. , and Mycetaeidae stat.n. The following taxa are redefined and characterized: Cleroidea s.n. , Cucujoidea s.n. , Cerylonidae s.n. , Bothrideridae s.n. , Endomychidae s.n. A new subfamily, Cyclotominae stat.n. , is described. Stenotarsinae syn.n. is formally subsumed within a new concept of Endomychinae s.n.     

Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera)

Phylogenetic relationships within the Pentatomoidea are investigated through the coding and analysis of character data derived from morphology and DNA sequences. In total, 135 terminal taxa were investigated, representing most of the major family groups; 84 ingroup taxa are coded for 57 characters in a morphological matrix. As many as 3500 bp of DNA data are adduced for each of 52 terminal taxa, including 44 ingroup taxa, comprising the 18S rRNA, 16S rRNA, 28S rRNA, and COI gene regions. Character data are analysed separately and in the form of a total evidence analysis. Major conclusions of the phylogenetic analysis include: the concept of Urostylididae is restricted to that of earlier authors; the Saileriolinae is raised to family rank and treated as the sister group of all Pentatomoidea exclusive of Urostylididae sensu stricto; a broadly conceived Cydnidae, as recognized by Dolling, 1981 , is not supported; the placement of Thaumastellidae within the Pentatomoidea is affirmed and the taxon is recognized at family rank rather than as a subfamily of Cydnidae, although its exact phylogenetic position within the Pentatomoidea remains equivocal; the Parastrachiinae is treated as also including Dismegistus Amyot & Serville and placed within a broadly conceived Corimelaenidae, the latter group being treated at family rank; the family‐group taxa Dinidoridae and Tessaratomidae probably represent a monophyletic group, but the recognition of monophyletic subgroups will benefit from additional representation in the sequence data set; and the Lestoniidae is treated as the sister group of the Acanthosomatidae. The Acanthosomatidae and Scutelleridae are consistently recovered as monophyletic. The monophyly of the Pentatomidae appears unequivocal, inclusive of the Aphylinae and Cyrtocorinae, on the basis of morphology, the latter two taxa not being represented in the molecular data set. © The Willi Hennig Society 2008.     

A global phylogeny of apple snails: Gondwanan origin, generic relationships, and the influence of outgroup choice (Caenogastropoda: Ampullariidae)

Apple snails (Ampullariidae) are a diverse family of pantropical freshwater snails and an important evolutionary link to the common ancestor of the largest group of living gastropods, the Caenogastropoda. A clear understanding of relationships within the Ampullariidae, and identification of their sister taxon, is therefore important for interpreting gastropod evolution in general. Unfortunately, the overall pattern has been clouded by confused systematics within the family and equivocal results regarding the family's sister group relationships. To clarify the relationships among ampullariid genera and to evaluate the influence of including or excluding possible sister taxa, we used data from five genes, three nuclear and two mitochondrial, from representatives of all nine extant ampullariid genera, and species of Viviparidae, Cyclophoridae, and Campanilidae, to reconstruct the phylogeny of apple snails, and determine their affinities to these possible sister groups. The results obtained indicate that the Old and New World ampullariids are reciprocally monophyletic with probable Gondwanan origins. All four Old World genera, Afropomus, Saulea, Pila, and Lanistes, were recovered as monophyletic, but only Asolene, Felipponea, and Pomella were monophyletic among the five New World genera, with Marisa paraphyletic and Pomacea polyphyletic. Estimates of divergence times among New World taxa suggest that diversification began shortly after the separation of Africa and South America and has probably been influenced by hydrogeological events over the last 90 Myr. The sister group of the Ampullariidae remains unresolved, but analyses omitting certain outgroup taxa suggest the need for dense taxonomic sampling to increase phylogenetic accuracy within the ingroup. The results obtained also indicate that defining the sister group of the Ampullariidae and clarifying relationships among basal caenogastropods will require increased taxon sampling within these four families, and synthesis of both morphological and molecular data. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 61–76.     

Molecular phylogeny of rootworms and related galerucine beetles (Coleoptera: Chrysomelidae)

The Galerucinae (Coleoptera: Chrysomelidae) sensu stricto (true galerucines) comprise a large assemblage of diverse phytophagous beetles containing over 5000 described species. Together with their sister taxon, the flea beetles, which differ from true galerucines by having the hind femora usually modified for jumping, the Galerucinae sensu lato comprises over 13 000 described species and is the largest natural group within the Chrysomelidae. Unlike the flea beetles, for which robust hierarchical classification schemes have not been erected, an existing taxonomic structure exists for the true galerucines, based mostly on the works of the late John Wilcox. In the most recent taxonomic list of the Galerucinae sensu stricto, five tribes were established comprising 29 sections housing 488 genera. The majority of the diversity within these tribes is found within the tribe Luperini, in which two genera, Monolepta and Diabrotica, are known to contain over 500 described species. Here, we extend the work from previous phylogenetic studies of the Galerucinae by analysing four amplicons from three gene regions (18S and 28S rRNA; COI) representing 249 taxa, providing the largest phylogenetic analysis of this taxon to date. Using two seven‐state RNA models, we combine five maximum likelihood models (RNA + DNA for the rRNAs; three separate DNA models for the COI codon positions) for these partitions and analyse the data under likelihood using Bayesian inference. The results of these two analyses are compared with those from equally weighted parsimony. Instead of choosing the results from one optimality criterion over another, either based on statistical support, tree topology or philosophical predisposition, we elect to draw attention to the similar results produced by all three analyses, illustrating the robustness of the data to these different analytical methods. In general, the results from all three analyses are consistent with each other and previous molecular phylogenetic reconstructions for Galerucinae, except that increased taxon sampling for several groups, namely the tribes Hylaspini and Oidini, has improved the phylogenetic position of these taxa. As with previous analyses, under‐sampled taxa, such as the Old World Metacyclini and all sections of the subtribe Luperina, continue to be unstable, with the few taxa representing these groups fluctuating in their positions based on the implemented optimality criterion. Nonetheless, we report here the most comprehensive phylogenetic estimation for the Galerucinae to date.     

MULTIGENE ANALYSES OF PHOTOSYNTHETIC EUGLENOIDS AND NEW FAMILY,PHACACEAE (EUGLENALES)1

Bayesian and maximum‐likelihood (ML) analyses of the combined multigene data (nuclear SSU rDNA, and plastid SSU and LSU rDNA) were conducted to evaluate the phylogeny of photosynthetic euglenoids. The combined data set consisted of 108 strains of photosynthetic euglenoids including a colorless sister taxon. Bayesian and ML analyses recovered trees of almost identical topology. The results indicated that photosynthetic euglenoids were divided into two major clades, the Euglenaceae clade (Euglena, Euglenaria, Trachelomonas, Strombomonas, Monomorphina, Cryptoglena, Colacium) and the Phacaceae clade (Phacus, Lepocinclis, Discoplastis). The Euglenaceae clade was monophyletic with high support and subdivided into four main clades: the Colacium, the Strombomonas and Trachelomonas, the Cryptoglena and Monomorphina, and the Euglena and Euglenaria clades. The genus Colacium was positioned at the base of the Euglenaceae and was well supported as a monophyletic lineage. The loricate genera (Strombomonas and Trachelomonas) were located at the middle of the Euglenaceae clade and formed a robust monophyletic lineage. The genera Cryptoglena and Monomorphina also formed a well‐supported monophyletic clade. Euglena and the recently erected genus Euglenaria emerged as sister groups. However, Euglena proxima branched off at the base of the Euglenaceae. The Phacaceae clade was also a monophyletic group with high support values and subdivided into three clades, the Discoplastis, Phacus, and Lepocinclis clades. The genus Discoplastis branched first, and then Phacus and Lepocinclis emerged as sister groups. These genera shared a common characteristic, numerous small discoid chloroplasts without pyrenoids. These results clearly separated the Phacaceae clade from the Euglenaceae clade. Therefore, we propose to limit the family Euglenaceae to the members of the Euglena clade and erect a new family, the Phacaceae, to house the genera Phacus, Lepocinclis, and Discoplastis.     

Phylogenetic analysis of the Brachyura (Crustacea, Decapoda) based on characters of the foregut with establishment of a new taxon

The Brachyura, within the decapod crustaceans, is one of the most species-rich taxa with up to 10 000 species. However, its phylogenetic history, evolution and fossil record remain subjects of controversy. In our study, we examined the phylogenetic relationships of the Brachyura based on morphological characters of the foregut. The cladistic analysis supports a monophyletic Brachyura including the Dromiidae and Raninidae. A clade comprising Dromiidae and Dynomenidae forms the most basal assemblage within the Brachyura, followed by the Homolidae and Latreilliidae. As a result, neither Podotremata nor Archaeobrachyura form a clade. In contrast, foregut data suggest that the classical taxon Oxystomata, comprising Calappidae, Parthenopidae, Dorippidae, Leucosiidae, Cymonomidae and Raninidae, is monophyletic. This makes the Heterotremata paraphyletic or polyphyletic. A newly established taxon, Neobrachyura, embraces some representatives of the Heterotremata and the monophyletic Thoracotremata.     

The interrelationships of Placodontia

Five terminal taxa (at the generic level) of Placodontia are recognized; the status of Psephosaurus remains problematical. A cladistic analysis of the interrelationships of Placodontia, based on 30 characters, results in two equally parsimonious trees. The Placodontia comprise two major subclades, the Placodontoidea and the Cyamodontoidea. Within the Placodontoidea, Paraplacodus is the sister‐taxon of Placodus. Within the Cyamodontoidea, Henodus is the most basal clade in one tree, a crown‐group cyamodontoid (the sister‐taxon of Placochelys) in the second tree. Cyamodus is the sister‐taxon of a clade comprising Placochelys and Psephoderma in the first tree, and is the most basal cyamodontoid clade in the second tree. The second tree is provisionally accepted because of the late appearance of Henodus in the fossil record of placodonts. The significance of these findings for the reconstruction of the paleobiogeographical history of the group is discussed.     

Quo vadis eohippus? The systematics and taxonomy of the early Eocene equids (Perissodactyla)

The systematics and taxonomy of early Eocene equids are investigated. A paraphyletic sequence of equid taxa is recovered from a phylogenetic analysis of 40 taxa and 121 characters. This analysis supports the identification of Hyracotherium as a primitive equoid and its restriction to the genotype, Hyracotherium leporinum . Sifrhippus gen. nov. is erected for the sister taxon of all other equids, Hyracotherium sandrae Gingerich. Minippus gen. nov., the next more-derived equid clade, is erected for two small equids, M. index Cope and M. jicarillai nov. species. Arenahippus gen. nov. is erected for the next three sequentially more-derived equid taxa, A. grangeri Kitts, A. aemulor Gingerich, and A. pernix Marsh. The genus Xenicohippus , which is the next more-derived equid clade, is redefined to include X. craspedotum Cope. Eohippus Marsh, the next more-derived equid taxon, is resurrected for E. angustidens Cope. Pliolophus , the only early Eocene equid from Europe, is identified as the sister taxon to Protorohippus , a sequence of successively more-derived equid taxa consisting of P. montanum Wortman and P. venticolum Cope. Protorohippus venticolum is identified as the sister taxon of Orohippus . Systemodon Cope is resurrected for S. tapirinum Cope. This taxon has historically been placed within Hyracotherium yet this analysis allies it with Cymbalophus near the base of the perissodactyl radiation. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 134 , 141–256.