Molecular systematics of the bark lice infraorder Caeciliusetae (Insecta: Psocodea)

The phylogenetic relationships of bark lice and parasitic lice (Insecta: Psocodea) have been studied in a number of recent molecular phylogenetic analyses based on DNA sequences. Many of these studies have focused on the position of parasitic lice within the free‐living bark lice. However, fewer such studies have examined the relationships among major groups of free‐living bark lice and their implications for classification. In this study we focus on the infraorder Caeciliusetae, a large group of bark lice (?1000 species) within the suborder Psocomorpha. Using sequences of two mitochondrial and two nuclear genes, we estimated the phylogeny for relationships among the five recognized families within the infraorder Caeciliusetae. Based on the results, the sister‐group relationship and respective monophyly of Stenopsocidae and Dasydemellidae is strongly supported. Monophyly of the larger families Amphipsocidae and Caeciliusidae was not supported, although the causes of this were the placement of two distinct subfamilies (Paracaeciliinae and Calocaeciliinae). The monophyly of Asiopsocidae could not be tested because it was sampled only by one species. Based on these results and consideration of morphological characters, we propose a new classification for Caeciliusetae, recognizing six families: Amphipsocidae, Stenopsocidae, Dasydemellidae, Asiopsocidae, Paracaeciliidae and Caeciliusidae. We expect that this new classification will stabilize the higher‐level taxonomy of this group and help to identify groups in need of further work among these insects.     

Phylogeny of the Platyhelminthes and the evolution of parasitism

Robust phylogenies provide the basis for interpreting biological variation in the light of evolution. Homologous features provide phylogenetically informative characters whereas homoplasious characters provide phylogenetic noise. Both provide evolutionary signal. We have constructed molecular and morphologically based phylogenies of the phylum Platyhelminthes using a recently revised morphological character matrix and complete 18S and two partial 28S rRNA gene sequences in order to evaluate the emergence and subsequent divergence of parasitic forms. In total we examine 65 morphological characters, 97 18S rDNA, 41 Dl domain 28S rDNA, and 49 D3-D6 domain 28S rDNA sequences. For the molecular data there were 748, 132 and 249 phylogenetically informative sites for the 18S, Dl and D3-D6 28S rDNA data sets respectively. Morphological and molecular phylogenetic solutions are incongruent but not incompatible, and using the principles of conditional combination (18S rDNA + morphology passing Templeton's test) they demonstrate: a single and relatively early origin for the parasitic Neodermata (including the cestodes, trematodes and monogeneans); sister-group status between the cestodes and monogeneans, and between these taxa and the trematodes (digeneans and aspidogastreans). The sister-group to the Neodermata is likely to be a large clade of neoophoran turbellarians, based on combined evidence, or a clade consisting of the Fecampiid + Urastomid turbellarians, based on morphological evidence alone. The combined evidence solution for the phylogeny of fiatworms based on 18S rDNA and morphology is used to interpret morphological and life-history data and to support a model for the evolution and radiation of neodermatan parasites in the group.     

Comparative osteology of the Danio (Cyprinidae: Ostariophysi) axial skeleton with comments on Danio relationships based on molecules and morphology

Danio is a diverse group of small, colourful and easily bred freshwater fishes native to Southern Asia. Biological interest in danios has increased in recent years because the zebrafish, Danio rerio , has become an important model organism, particularly for studies of vertebrate developmental biology and genetics. Though several phylogenetic studies of Danio have been done on a subset of Danio species, the resulting phylogenies conflict in detail. To examine the utility of osteology for systematics of this group at the species level, we studied the axial skeleton for 11 species of Danio. We analyse our morphological data alone and combined with DNA sequence data for five gene sequences generated in earlier phylogenetic studies. The axial skeleton of Danio exhibits 14 characters that prove useful in phylogenetic analysis. Both molecular and morphological data support the monophyly of the danios included in our analysis and both data sets support the monophyly of two subclades: a deep-bodied group and a slender-bodied group. Separate analysis of molecular and morphological data sets show that the molecular data resolves relationships within the slender subclade whereas the topology of the deep-bodied subclade is determined by morphological data.  © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 2002, 135 , 529–546.     

Evolution and phylogeny of the scarab subtribe Anisopliina (Coleoptera: Scarabaeidae: Rutelinae: Anomalini)

Abstract.  The subtribe Anisopliina (Scarabaeidae: Rutelinae: Anomalini) is associated with grasses, and its species are distributed in the Palaearctic, Oriental, Ethiopian, Nearctic and Neotropical biogeographical regions. Phylogenetic analysis of adult morphological characters was conducted to examine the monophyly and classification of the group, as well as to examine characters associated with grass pollinivory and graminivory. We review the biology, phylogeny and classification of the Anisopliina and provide an overview of each genus. The analysis of ninety-one morphological characters using parsimony does not support the monophyly of the subtribe Anisopliina. Instead, the results provide support for a group referred to here as the anisopliine clade, a circum-Mediterranean group, forming an internal clade within the well-supported tribe Anomalini. Sister group relationships are discussed, possibly being associated with a New World anomaline taxon. Character states associated with grass herbivory, including mouthpart and leg characters, are discussed based on the phylogenetic analysis. Within the Anomalini, an evolutionary shift from generalized leaf feeding to grass associations and grass pollen feeding is supported.     

Phylogeny and revision of the leech genus Helobdella (Glossiphoniidae) based on mitochondrial gene sequences and morphological data and a special consideration of the triserialis complex

The relationships, as well as identification of species, within Helobdella (Glossiphoniidae) were explored through phylogenetic analysis and through an overview of the historical systematics of the genus. The phylogeny was determined using morphological data and the mitochondrial gene sequences of cytochrome c oxidase subunit I and nicotinamide adenine dinucleotide dehydrogenase subunit I. A broad representation of 15 ingroup species was sampled, including 10 individuals from South America. Outgroup taxa included five species of Haementeria . Cladistic analysis of all available data resulted in one most parsimonious tree. Results shed light on genetic divergence of members classified as the same species, including those that are not monophyletic. Historically, external morphological characters have played a significant role in contributing to the confusion in the classification of H. triserialis, H. papillata, H. lineata and H. fusca in North America. Re-evaluation of Verril's Clepsine papillifera var. b and var. d in a phylogenetic context provides a solution. Additionally, the genera Adaetobdella, Acritobdella, Dacnobdella and Gloiobdella created by Ringuelet are returned to Helobdella based on overlapping morphological characters.     

A morphological phylogeny for four families of amblyceran lice (Phthiraptera: Amblycera: Menoponidae, Boopiidae, Laemobothriidae, Ricinidae)

The suborder Amblycera (Insecta: Phthiraptera) comprises seven recognized families of parasitic lice. Three of these families (the Menoponidae, Laemobothriidae and Ricinidae) are present on a wide range of avian hosts. The four remaining families are restricted to a small section of mammals (the Boopiidae are parasites of Australian and New Guinean marsupials, and the Gyropidae, Trimenoponidae and Abrocomophagidae parasitize South and Central American rodents). This study uses a morphological approach to examine the evolutionary relationships between the genera from four amblyceran families: the Menoponidae, Boopiidae, Laemobothriidae and Ricinidae. Genera are represented by exemplars and a total of 44 louse taxa and one outgroup taxon were included. A cladistic analysis of 147 unordered characters recovered six equally parsimonious trees. Bootstrap, jackknife and Bremer support analyses were undertaken to assess the level of support for each resolved node in the strict consensus topology. Strong support was found for deep branch relationships between the families and in some cases for supra-generic groupings within families. The clades present in the strict consensus tree are discussed with reference to supra-generic and interfamily relationships, character choice, morphological convergence and host distribution. This study is the first phylogeny presented solely for amblyceran genera.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society , 2003, 138 , 39–82.     

Phylogenetic analysis of partial sequences of elongation factor 1alpha identifies major groups of lice (Insecta: Phthiraptera)

As a first attempt to use molecular data to resolve the relationships between the four suborders of lice and within the suborder Ischnocera, we sequenced a 347-bp fragment of the elongation factor 1alpha gene of 127 lice (Insecta: Phthiraptera) as well as outgroup taxa from the order Psocoptera. A number of well-supported monophyletic groups were found but the relationships among many of these groups could not be resolved. While it is probable that multiple substitutions at high divergences and ancient radiation over a short period of time have contributed to the problem, we attribute most of this lack of resolution to the high ratio of taxa to characters. Nevertheless, the sequence data unequivocally support a number of important relationships that are at variance with the conclusions of morphological taxonomy. These include the sister group relationship of Chelopistes and Oxylipeurus, two lice occupying different ecological niches on the same host, which have previously been assigned to different families. These results provide evidence in support of the hypothesis that lice have speciated in situ on the host in response to niche specialization and that this has given rise to convergent morphologies in the lice of different host groups which share similar ecological niches. We discuss our attempts to overcome the limitations of this large data set, including the use of leaf stability analysis, a new method for analyzing the stability of taxa in a phylogenetic tree, and examine a number of hypotheses of relationships based on both traditional taxonomy and host associations.     

Phylogenomics and host-switching patterns of Philopteridae (Psocodea: Phthiraptera) feather lice

Philopteridae feather lice are a group of ectoparasitic insects which have intimate relationships with their avian hosts. Feather lice include an enormous number of described species; however, the relationships of major lineages have been clouded by homoplasious characters due to convergent evolution. In this study, a comprehensive phylogenomic analysis of the group is performed which includes 137 feather louse species. Several other analyses are also completed including dating analysis, cophylogenetic reconstructions, and ancestral character estimation to understand the evolution of complex morphological and ecological traits. Phylogenetic results recover high support for the placement of major feather louse lineages, but with lower support for long-branched enigmatic genera found at the base of the tree. The results of dating analyses suggest modern feather lice began to diversify approximately 49 million years ago following the adaptive radiation of their avian hosts. Cost-based cophylogenetic reconstructions recover a high frequency of host switching, while congruence-based methods indicate a significant level of congruence between host and parasite trees. Ancestral state reconstructions favour a generalist ancestor and water bird host at the root. The analyses completed provide insight into the evolution of a diverse group of ectoparasitic insects which infest a wide variety of avian hosts. The results represent the most comprehensive phylogenetic hypothesis of the group to date and provide a framework for future classification of the family into natural groupings.     

The systematic relationships of glucosinolate-producing plants and related families: a cladistic investigation based on morphological and molecular characters

A cladistic analysis is performed using 94 morphological and biochemical characters for 42 genera to compare a phylogeny based on morphological data with those obtained using different genes ( rbc L, atp B, 18S RNA, mat K) or their combination with morphological data, and to understand the floral evolution within the expanded Brassicales (Capparales) relative to Sapindales and Malvales. The tree produced with morphological data is congruent with those obtained from macromolecular studies in obtaining a well-supported glucosinolate-producing clade and an expanded Sapindales. The combined analysis of the morphological and molecular characters is generally well resolved with support for many of the relationships. The inclusion of the fossil taxon Dressiantha demonstrates the value of inserting fossil evidence in phylogenetic analyses. However, the fossil appears to be related to the Anacardiaceae and not to the Brassicales. The core Brassicales are well supported by a number of synapomorphies, although the internal position of Tovariaceae and Pentadiplandraceae is not well resolved. Emblingiaceae appears to be related to Bataceae and Salvadoraceae. Several significant morphological characters are mapped on the combined trees and their evolutionary significance is discussed. Within Brassicales and Sapindales several well supported clades can be recognized which merit ordinal or subordinal status, putting the present orders at a higher level; these include: Tropaeolales, Setchellanthales, Batidales, Brassicales (Brassiciflorae), Burserales, Sapindales and Rutales (Sapindiflorae). The present scheme of affinities within the Brassicales corresponds well with a gradual morphological evolution in the order.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 453–494.     

Evolutionary trends in Tetrastigma (Vitaceae): Morphological diversity and taxonomic implications

Tetrastigma (Miq.) Planch. (Vitaceae) is a genus with ca. 100 species showing great morphological diversity. Previous molecular phylogenetic studies suggested that traditional classification systems are not consistent with the molecular phylogeny, and Tetrastigma is undergoing further systematic investigation. We traced the evolutionary trends of 20 morphological characters within a robust phylogenetic framework. Our results revealed that many morphological characters show either multiple transitions or few state changes, however, some characters show distinct variation. The two subgenera in Tetrastigma (subgen. Tetrastigma and subgen. Palmicirrata) based on unbranched/bifurcate versus digitately branched tendrils are not supported because subgen. Tetrastigma is paraphyletic. However, the unbranched versus bifurcate/digitately branched tendril is of taxonomic utility to characterize some of the major clades. Inflorescences in Tetrastigma appear axillary, but are leaf‐opposed on a compressed axillary shoot. We found most of the species in Tetrastigma retained the ancestral compound dichasial inflorescence, except those of clade IV that have derived pseudo‐umbellate inflorescences. Other characters including habit, leaf organization, and berry shape provide additional morphological support for the major clades. Our morphological analysis and recent molecular study suggest each of the five major clades within Tetrastigma be treated as distinct taxonomic sections (five sections in the genus).     

Comparative histology of the vaginal–cloacal region in Squamata and its phylogenetic implications

We described the histology and morphology of the vaginal–cloacal region in 18 species from 12 Squamata families. This comparative study revealed a wide variation in the cloacal morphology. Fifteen morphological characters were considered to be primary homology hypotheses and were optimized over the topology derived from the parsimony analysis of the available soft morphological evidence, including the characters described in this study. The synapomorphies optimized for Squamata are bifid urodaeum, common urodaeal cavity with similar histological features of the urodaeal horns, and presence of glands in the anterior urodaeum; for Scleroglossa the synapomorphy is the lateral position of the vaginal intrusion into the anterior urodaeal chamber, for Nyctisaura + Scincomorpha the synapomorphy is the presence of a bifid posterior urodaeum; and for Xantusidae + Annulata it is the presence of simple glands in the anterior urodaeum. The central position of the vaginal intrusion into the urodaeal chamber and the intraepithelial position of the glandular unit in the anterior urodaeum behave as autapomorphies for Iguanidae. This study contributes evidence that defines the relationships within Scleroglossa. Cloacal features provide interesting information that is useful as a source of morphological characters for phylogenetic studies in Squamata.     

Changes in base composition bias of nuclear and mitochondrial genes in lice (Insecta: Psocodea)

While it is well known that changes in the general processes of molecular evolution have occurred on a variety of timescales, the mechanisms underlying these changes are less well understood. Parasitic lice (“Phthiraptera”) and their close relatives (infraorder Nanopsocetae of the insect order Psocodea) are a group of insects well known for their unusual features of molecular evolution. We examined changes in base composition across parasitic lice and bark lice. We identified substantial differences in percent GC content between the clade comprising parasitic lice plus closely related bark lice (=Nanopsocetae) versus all other bark lice. These changes occurred for both nuclear and mitochondrial protein coding and ribosomal RNA genes, often in the same direction. To evaluate whether correlations in base composition change also occurred within lineages, we used phylogenetically controlled comparisons, and in this case few significant correlations were identified. Examining more constrained sites (first/second codon positions and rRNA) revealed that, in comparison to the other bark lice, the GC content of parasitic lice and close relatives tended towards 50 % either up from less than 50 % GC or down from greater than 50 % GC. In contrast, less constrained sites (third codon positions) in both nuclear and mitochondrial genes showed less of a consistent change of base composition in parasitic lice and very close relatives. We conclude that relaxed selection on this group of insects is a potential explanation of the change in base composition for both mitochondrial and nuclear genes, which could lead to nucleotide frequencies closer to random expectation (i.e., 50 % GC) in the absence of any mutation bias. Evidence suggests this relaxed selection arose once in the non-parasitic common ancestor of Phthiraptera + Nanopsocetae and is not directly related to the evolution of the parasitism in lice.     

Basal ischnoceran louse phylogeny (Phthiraptera: Ischnocera: Goniodidae and Heptapsogasteridae)

A phylogenetic analysis of generic relationships for avian chewing lice of families Goniodidae and Heptapsogasteridae (Phthiraptera: Ischnocera) is presented. These lice, hosted by galliform, columbiform and tinamiform birds are reputedly basal in the phylogeny of Ischnocera. A cladistic analysis of sixty‐two adult morphological characters from thirty‐one taxa revealed thirty equally parsimonious cladograms. The phylogeny is well resolved within Heptap‐sogasteridae and supports the monophyly of subfamily Strongylocotinae (sensu Eichler 1963 ). Resolution within Goniodidae is lower but suggests that the genera hosted by Columbiformes are largely monophyletic. Mapping host taxonomy on to the phylogeny of the lice reveals a consistent pattern which is largely congruent down to the rank of host family, although at lower taxonomic levels the association appears to be more complex. The inclusion of more louse taxa may help considerably to unravel the coevolutionary history of both the hosts and their parasites.     

Cophylogenetic relationships between penguins and their chewing lice

It is generally thought that the evolution of obligate parasites should be linked intimately to the evolution of their hosts and that speciation by the hosts should cause speciation of their parasites. The penguins and their chewing lice present a rare opportunity to examine codivergence between a complete host order and its parasitic lice. We estimated a phylogeny for all 15 species of lice parasitising all 17 species of penguins from the third domain of the mitochondrial 12S ribosomal rRNA gene, a portion of the mitochondrial cytochrome oxidase subunit 1 gene and 55 morphological characters. We found no evidence of extensive cospeciation between penguins and their chewing lice using TreeMap 2.02beta. Despite the paucity of cospeciation, there is support for significant congruence between the louse and penguin phylogenies due to possible failure to speciate events (parasites not speciating in response to their hosts speciating).     

First phylogenetic analysis of the tribe Phyllotini (Rodentia: Sigmodontinae) combining morphological and molecular data

Previous phylogenetic analyses of the tribe Phyllotini, one of the largest components of the subfamily Sigmodontinae, have been based on a single source of evidence. In particular, morphological analyses were largely based on craniodental data, almost neglecting the potential phylogenetic information present in the postcranium. Despite the significant advances made in relation to the knowledge of phyllotine phylogeny in recent times, there are several unsolved issues that highlight the importance of a phylogenetic analysis that integrates multiple sources of evidence, including previously considered sources as well as new sources of data. We present here the first combined phylogenetic analysis (morphological and molecular) of phyllotines, which includes the widest taxon and character sampling to date. Our dataset includes 164 morphological characters, of which 83 are postcranial characters, plus 3561 molecular characters, scored for 52 species from 34 genera of Oryzomyalia. In this study 75 postcranial characters not previously considered in this group are thoroughly described, and their utility for solving the relationships within Phyllotini is evaluated by means of different complementary analyses. Phyllotini was retrieved as a monophyletic clade in the combined analysis, with a composition that matches that obtained in most other recent analyses. All genera of phyllotines were monophyletic and show high support values. Abrotrichini, Akodontini and Oryzomyini were also monophyletic. The inclusion of postcranial data appears to be of limited utility to solve the phylogenetic relationships within Phyllotini.     

Molecular systematics of Psocomorpha (Psocoptera)

Abstract.  Previous classification of the insect order Psocoptera has relied on morphological characters. Psocoptera are generally divided into three suborders: Trogiomorpha, Troctomorpha, and Psocomorpha. Traditional classification divides the Psocomorpha into four infraorders (Homilopsocidea, Caeciliusetae, Psocetae and Epipsocetae), but a recent morphological cladistic study removed Archipsocidae from Homilopsocidea and Hemipsocidae from Psocetae. We investigated the phylogenetic relationships within the suborder Psocomorpha using DNA sequences from the nuclear 18S and mitochondrial 16S, 12S and cytochrome oxidase I genes. Phylogenetic analyses of these gene sequences supported monophyly for Psocomorpha. In addition, monophyly of the traditional subgroups Caeciliusetae and Psocetae was generally supported. Monophyly of Homilopsocidea was not supported, and Archipsocus is removed from this group. Although the molecular phylogeny is generally consistent with recent cladistic studies of morphological characters, we found no evidence that Hemipsocidae should be removed from Psocetae.     

Morphological,genetic and behavioural analyses of a hybrid zone between the ground beetles Carabus lewisianus and C. albrechti (Coleoptera,Carabidae): asymmetrical introgression caused by movement of the zone?

We analysed the putative hybrid zone between the ground beetles Carabus lewisianus Breuning and C. albrechti Morawitz from the Kanto and Tanzawa Mountains in central Honshu, Japan, using morphological, genetic, and behavioural data. Canonical discriminant analysis of three external and five genital morphological characters revealed an apparent morphological gap, suggesting restricted sympatry in the contact zone. RFLP and molecular phylogenetic analyses of the mitochondrial gene ND5 revealed that haplotypes originating from C. lewisianus introgressed extensively into C. albrechti . Fitting tanh curves to morphological (external and genital) and genetic characters showed differential cline widths and centres, suggesting stronger selection for genital morphology with narrower cline widths, and extensive introgression of the nuclear genes responsible for external characters relative to those controlling genital morphology into the range of C. albrechti . Linkage disequilibria between the morphological characters did not differ from zero, suggesting sufficient recombination occurred in the zone but the effect of small sample sizes was not negligible. Mate choice trials demonstrated that males showed a weak but not significant preference for conspecific mates. We interpret these patterns as evidence for (1) partial reproductive isolation presumably by postmating processes; (2) selection against intermediate genital morphologies, and (3) independent responses of the characters to different evolutionary forces that may cause movement of genital clines and introgression of the mitochondrial gene and external morphology. The movement of the boundaries may have resulted in the particular species distribution patterns in the study area.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 79–94.     

Assessing phylogenetic resolution among mitochondrial, nuclear, and morphological datasets in Nothonotus darters (Teleostei: Percidae)

External morphological characters are the basis of our understanding of diversity and species relationships in many darter clades. The past decade has seen the publication of many studies utilizing mtDNA sequence data to investigate darter phylogenetics, but only recently have nuclear genes been used to investigate darter relationships. Despite a long tradition of use in darter systematics few studies have examined the phylogenetic utility of external morphological characters in estimating relationships among species in darter clades. We present DNA sequence data from the mitochondrial cytochrome b (cytb) gene, the nuclear encoded S7 intron 1, and discretely coded external morphological characters for all 20 species in the darter clade Nothonotus. Bayesian phylogenetic analyses result in phylogenies that are in broad agreement with previous studies. The cytb gene tree is well resolved, while the nuclear S7 gene tree lacks phylogenetic resolution, node support, and is characterized by a lack of reciprocal monophyly for many of the Nothonotus species. The phylogenies resulting from analysis of the morphological dataset lack resolution, but nodes present are found in the cytb and S7 gene trees. The highest resolution and node support is found in the Bayesian combined data phylogeny. Based on our results we propose continued exploration of the phylogenetic utility of external morphological characters in other darter clades. Given the extensive lack of reciprocal monophyly of species observed in the S7 gene tree we predict that nuclear gene sequences may have limited utility in intraspecific phylogeographic studies of Nothonotus darters.     

Evolution of the bomolochiform superfamily complex (Copepoda: Cyclopoida): new insights from ssrDNA and morphology, and origin of Umazuracolids from polychaete-infesting ancestors rejected

Poecilostome cyclopoids are among the most morphologically diverse copepods, having established symbiotic relationships with teleosts, elasmobranchs and invertebrate hosts belonging to no fewer than 14 marine phyla. Many parasitic lineages display radically divergent body plans and on that basis have traditionally been placed at higher taxonomic rank than they deserve. The most recent example is the monotypic family Umazuracolidae, established for a derived fish parasite with bomolochiform affinities. Phylogenetic analysis of complete ssrDNA (18S) sequences of 44 species belonging to 21 families of cyclopoid copepods shows that there is no support for the familial distinctiveness of the Umazuracolidae. Both maximum parsimony tree reconstruction and Bayesian inference, operating under the GTR+I+Γ model of nucleotide substitution, unambiguously placed Umazuracola elongatus in the Taeniacanthidae within the predominantly fish parasitic bomolochiform complex, refuting the original suggestion of a shared most recent common ancestry with polychaete symbionts. The phylogenies also revealed that the bomolochiform families and the Clausidiidae (and allies) form a monophyletic group, the clausidiiform complex, with high nodal support under both methods. Bayesian inference suggested a diphyletic origin of the "Poecilostomatoida" with the clausidiiform family-group holding a basal position while the traditional cyclopoid families form a monophyletic group in apposition to a second poecilostomatoid clade; however, maximum parsimony results were equivocal, depending on outgroup selection. Scrutiny of the morphological characters diagnosing the monotypic families Tegobomolochidae and Tuccidae demonstrated that they merely represent derived lineages within more inclusive taxa, the former being related to a group of nostril-inhabiting genera within the Bomolochidae, the latter forming the sistergroup of Taeniacanthodes within the Taeniacanthidae. The taeniacanthid genus Makrostrotos occupies a position at the base of the bomolochiform complex and is fixed as the type of a new family, Makrostrotidae. Although both morphological and molecular evidence hint that the Bomolochidae is nested within a paraphyletic Taeniacanthidae, the status quo of maintaining both families is favoured here pending additional molecular data. The bomolochiform complex, comprising the Bomolochidae, Taeniacanthidae, Telsidae and Makrostrotidae, is attributed superfamilial rank as the Bomolochoidea. A recent controversial phylogenetic analysis of the poecilostomatoid families is shown to be flawed, being based on a dataset containing imperfect or misleading information, and characters whose states were wrongly assessed.