Evolution of attachment structures in the highly diverse Acercaria (Hexapoda)

Acercaria display an unusually broad array of adhesive devices occurring on different parts of the legs. Attachment structures of all major subgroups are described and illustrated. Nineteen characters of the distal leg region were combined with a data matrix containing 99 additional morphological characters of different body parts. The results of the cladistic analysis are largely congruent with current hypotheses. Zoraptera are not retrieved as close relatives of Acercaria. The monophyly of the entire lineage and of the major subgroups Psocodea, Phthiraptera, and Hemiptera is confirmed. Our data also support the monophyly of Auchenorrhycha and a sister‐group relationship between Thysanoptera and Hemiptera (Condylognatha). In contrast to other lineages of insects, the hairy type of adhesive device is present only in one group within the Acercaria (Heteroptera, Cimicomorpha). The arolium is present in the groundplan but missing in several groups (e.g. Psocodea, Cicadoidea, Aphidoidea). Pretarsal pulvilli evolved several times independently. Tarsal euplantulae and different specialized clasping devices have evolved within Phthiraptera, whereas pretarsal attachment devices are missing in this ectoparasitic group. The potential to modify pretarsal attachment devices in their structural details has probably contributed to the very successful diversification of the predominantly phytophagous Hemiptera.     

Chromosomal diversity and phylogenetic inferences concerning thrips (Insecta, Thysanoptera) in a semi-arid region of Brazil

The order Thysanoptera is composed of cosmopolitan phytophagous and predaceous insects with diverse life histories, behaviors and habits. This order is currently thought to form a trichotomy with Hemiptera and Psocodea; Hemiptera and Thysanoptera are considered to be sister groups. The interrelationships within Thysanoptera remain unclear and cytotaxonomic studies are scarce in thrips. We report, for the first time, chromosomal data on seven species of thrips collected from a semi-arid region in the States of Bahia and Pernambuco (Northeast Brazil). A distinctive chromosomal pattern was observed in Thysanoptera when compared to other members within the infraclass Paraneoptera. Considerable karyotypic differences were also found within genera and species of Thysanoptera. Based on these data, we suggest that Paraneoptera forms a polyphyletic group and that Terebrantia and Tubulifera should be regarded as sister groups. The high chromosomal variability observed in Thysanoptera indicates that chromosomal rearrangements have played a key role in their speciation pathways.     

Study on the systematic position of Metriini based on characters of the larval head (Coleoptera: Carabidae)

Abstract. Characters of the head of larvae of Metrius contractus Eschscholtz, Ozaenini and Paussini are interpreted phylogenetically. The monophyly of Metriini + Ozaenini + Paussini is substantiated by several synapomorphies such as hyperprognathism and strong constriction of the neck. Ozaenini and Paussini together form the sister-group of Metriini. Ozaenini are paraphyletic. The monophyly of Paussini + Ozaenini excluding Pachyteles is indicated by two possible synapomorphies. Several synapomorphies are shared by Physea + Paussini. Secondary prognathism, large membranous submento-mental area and other derived features are considered autapomorphies of Paussini. Paussini excluding Platyrhopalopsis are characterized by the loss of the palpifer. The monophyly of a group which comprises Geadephaga excluding Trachypachini is suggested by several synapomorphic features. A very basal position of the metriine—paussine lineage within Carabidae is indicated by several plesiomorphic features. A hypopharyngeal filter apparatus with a dense fringe of well-arranged, long hairs is a possible autapomorphy of Anisochaeta. The results of this study do not indicate a close relationship between the metriine—paussine lineage and the tribes Brachinini and Crepidogastrini as has been suggested in recent works.     

Phylogenetics and classification of Chalcidoidea and Mymarommatoidea — a review of current concepts (Hymenoptera, Apocrita)

Classification and morphological and molecular evidence supporting relationships of Mymarommatidae (Mymarommatoidea) and the 20 families of Chalcidoidea are reviewed. Five autapomorphies support monophyly of Mymarommatoidea, at least two autapomorphies support monophyly of Chalcidoidea, and three synapomorphies support a sister-group relationship between Mymarommatoidea and Chalcidoidea. Mymaridae are indicated as the likely sister group of all other Chalcidoidea by: two features of the ovipositor, the unique structure of a muscle between the mesofurca and axillary lever, and sequence data from the 28s rDNA gene. Structure of the upper valvulae of the ovipositor could indicate Rotoitidae as the second-most basal clade of Chalcidoidea. Chalcididae, Elasmidae, Encyrtidae, Eulophidae, Eurytomidae, Leucospidae, Mymaridae, Ormyridae, Rotoitidae, Signiphoridae, Torymidae and Trichogrammatidae are each indicated as monophyletic by at least one putative synapomorphy, but could render other families paraphyletic. Aphelinidae, Eupelmidae, Pteromalidae, and Tetracampidae are not demonstrably monophyletic. Agaonidae is monophyletic only if restricted to Agaoninae, and Eucharitidae is monophyletic only if restricted to Eucharitinae + Oraseminae. Eupelmidae may be paraphyletic with respect to Tanaostigmatidae and Encyrtidae, and Tanaostigmatidae including Cynipencyrtus may be paraphyletic relative to Encyrtidae. Perilampidae (Perilampinae + Chrysolampinae) are either polyphyletic or paraphyletic with respect to Eucharitidae + Akapalinae + Philomidinae. No cladistic hypotheses of familial relationships based on character evidence have considered the superfamily in its entirety.     

Phylogenetic analysis of Adephaga (Coleoptera) based on characters of the larval head

Abstract. Characters of the head of adephagan larvae were examined and analysed phylogenetically. A labrum which is completely fused to the clypeofrons and the presence of a closed prepharyngeal tube are autapomorphies of Adephaga. Partial reduction of the fossa maxillaris, cardo and stipes forming a functional unit, the immobilization of the lacinia, attachment of M. craniolacinialis to the lateral stipital wall, and loss of one stipitopalpal muscle, are considered autapomorphies of Adephaga excluding Gyrinidae. Complete reduction of the fossa maxillaris and the presence of M. craniostipitalis medialis are possible autapomorphies of Adephaga excluding Gyrinidae and Haliplidae. The presence of caudal tentorial arms, insertion of the galea on the mesal side of palpomere I, and absence of the lacinia are considered synapomorphies of Trachypachidae and Dytiscoidea (Noteridae, Amphizoidae, Hygrobiidae, Dytiscidae). The presence of a slender, elongated process of the head capsule, which articulates with a corresponding socket of the cardo, is a possible autapomorphy of Dytiscoidea. The sinuate frontal sutures, distinctly protruding prementum, shortened M. craniostipitalis medialis, and absence of M. submentopraementalis are considered autapomorphies of Geadephaga excluding Trachypachidae. The presence of a regular row of hairs along the anterior hypopharyngeal margin is a possible autapomorphy of Geadephaga excluding Trachypachidae and Rhysodidae. Improvement of the hypopharyngeal filter apparatus suggests the monophyly of Anisochaeta. Presence of a penicillum and partial reduction of the lacinia are possible autapomorphies of Anisochaeta excluding Omophronini. Larvae of Cychrini, Carabini, Nebriini and Notiophilini are characterized by a strongly developed, cone-shaped hypodon. Postocular and cervical ridges, crosswise arrangement of antennal muscles, and a completely flattened hypopharynx are considered autapomorphies of Caraboidea Limbata.     

Phylogenomics of Hemiptera (Insecta: Paraneoptera) based on mitochondrial genomes

Hemiptera is the largest order in Paraneoptera and the fifth largest in Insecta. Disputes about hemipteran phylogeny have concerned the monophyly of Auchenorrhyncha and relationships between the suborders Fulgoromorpha, Cicadomorpha, Coleorrhyncha and Heteroptera. In a phylogenomic study of Hemiptera, we add two new mitochondrial genomes of Peloridiidae (Coleorrhyncha) to those reported in GenBank, to complete the taxon sampling of all suborders. We used two types of data – amino acid sequences and nucleotides of various combinations between protein coding genes, tRNAs and rRNAs – to infer the phylogeny of Hemiptera. In total 27 taxa of Paraneoptera were sampled, 24 of them being hemipterans. Bayesian inference, maximum likelihood and maximum parsimony analyses were employed. The relationship of Cicadomorpha + Heteroptera is always stable in the results with different combinations between data types and phylogenetic methods, but our results challenge the monophyly of ‘Homoptera’ and Auchenorrhyncha. In evaluating the relative contribution of each gene, the phylograms generated by single genes CO1, ND1, ND2, ND4 and ND5, respectively, closely matched the tree yielded by the combined datasets. In light of the taxon‐sampling sensitivity of trees based on mitochondrial genomes, the results need to be tested with further data from nuclear genes.     

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.     

Study of the larva of Nosodendron fasciculare (Olivier 1790) (Coleoptera: Nosodendridae) with implications for the phylogeny of Bostrichiformia

Internal and external features of larvae of Nosodendron fasciculare were examined and compared to character states found in other groups of Derodontoidea and Bostrichoidea. Synapomorphic larval features indicate a sistergroup relationship between Nosodendridae and Derodontidae: tubercular surface structure, body compressed dorsoventrally, tergites with lateral projections, spiracles located on tubular processus. These families share three derived character states with Jacobsoniidae in one of two equally parsimonious trees. However, the monophyletic origin of Nosodendridae + Derodontidae + Jacobsoniidae is not sufficiently established at present. The monophyly of Bostrichoidea (Dermestidae + Bostrichidae + Anobiidae + Ptinidae) is suggested by hypognathism. Larvae of these families are characterized by the absence of the mandibular mola and a robust apical part of the mandible. The monophyly of Bostrichidae + Anobiidae + Ptinidae is indicated by a C-shaped, grub like body and the abdominal apex formed by an enlarged and rounded segment IX. Bostrychiformia are probably paraphyletic. A closer relationship between Bostrichoidea with Cucujiformia is suggested by the possession of cryptonephric malpighian tubules in adults. The specific type of cryptonephridism in Bostrichoidea is probably derived from this condition and is considered autapomorphic. The monophyly of Nosodendridae ( Nosodendron ) is supported by several autapomorphies. The assignment of the supposed larva of Nosodendron ovatum remains unclear. An inclusion of the dermestid genus Orphilus in Nosodendridae is rejected. Muscular features of larvae of Nosodendron (and Derodontus ) are largely plesiomorphic.     

Phylogenetic analysis of Myxophaga (Coleoptera) using larval characters

A phylogenetic parsimony analysis of fifty-four larval characters of Myxophaga (excluding Lepiceridae) resulted in two minimal length cladograms. The monophyly of Torridincolidae, Hydroscaphidae and Microsporidae is supported by several autapomorphies: miniaturization, flattened body with laterally extended tergites, broadened head, scale-like surface structures, broad tentorial bridge, disc-shaped labral sensilla, spiracular gills and pupation in the last larval exuviae. Hydroscaphidae are the sister group of Microsporidae. Larvae of both families are characterized by semi-entognathous mouthparts, tergites with posterior rows of lancet-shaped setae, claws with flattened basal spines and balloon-shaped spiracular gills. The monophyly of all families is supported by autapomorphies. Torridincolidae excluding Delevea is defined as a monophylum by four derived character states: body ovoid, thorax semicircular and as long as abdomen, labral sensilla fused and abdominal sternite IX distinctly reduced and triangular. The monophyly of Torridincolinae (sensu Endrödy-Younga 1997b) is supported by two autapomorphies. The proposed branching pattern suggests that the early representatives of Myxophaga (excluding Lepiceridae) were living in aquatic conditions with a preference for hygropetric habitats. The tendency to live on rocks in running water and miniaturization have played an important role in myxophagan evolution.     

Review and preliminary phylogenetic analysis of the subfamilies of the Pyralidae (sensu stricto) (Lepidoptera: Pyraloidea)

Abstract. The morphological evidence on the monophyly of the subfamilies of the Pyralidae sensu stricto is reviewed, and a phylogeny is proposed for the Pyralidae. New autapomorphies are proposed for the monophyly of the Phycitinae, Pyralinae and Epipaschiinae. The phylogenetic analysis supports a sister group relationship between the Phycitinae and Epipaschiinae, a sister group relationship of the Pyralinae to the phycitine + epipaschiine clade. The galleriines and chrysaugines occupy basally unresolved positions.     

Phylogenetic relationships of the Mesozoic paraneopteran family Archipsyllidae (Insecta: Psocodea)

The Middle Jurassic Archipsylla sinica sp. n. is the first record of the enigmatic Mesozoic family Archipsyllidae from China. This well-preserved Chinese material bears several apomorphies allowing an attribution of this family to the Psocodea. The presence of four-segmented tarsi in Archipsyllidae suggests that the reduction in number of tarsomeres occurred independently at least two times in the modern paraneopteran lineages Psocodea (“Psocoptera” + Phthiraptera) and Condylognatha (Thysanoptera + Hemiptera).     

The head morphology of Clambidae and its implications for the phylogeny of Scirtoidea (Coleoptera: Polyphaga)

External and internal structures of the head of adults of Clambus are described and illustrated in detail. The results are compared with structural features found in the clambid genus Calyptomerus, in representatives of other scirtoid families, and also in species of other coleopteran suborders, notably Myxophaga. The results tentatively support the monophyly of Scirtoidea and a close relationship between Clambidae and Eucinetidae is suggested by one shared derived feature of the mandible, a long and slender apical tooth with a serrate edge. The monophyly of Clambidae is very strongly supported and Acalyptomerus is probably the sistergroup of a clade Calyptomerus + Clambinae. Potential scirtoid autapomorphies are the loss of the dorsal tentorial arms, a bulging gula, a strongly transverse labrum, and a ridge separating the mediostipes from the lacinia. However, all these features are homoplasious. The monophyly of Clambidae is supported by modifications of the head capsule which is strongly flattened and broadened, by a deep clypeofrontal incision enabling vertical antennal movements, and a series of antennal features. Synapomorphies of Clambinae + Calyptomerus (Clambidae excluding Acalyptomerus) are the conglobate body form with the ventral side of the head capsule in contact with the mesocoxae, and compound eyes integrated in the contour of the head. The completely subdivided eye is an autapomorphy of Clambus. An entire series of features is shared by Clambidae (or Scirtoidea) and Myxophaga. Most of them are apomorphies that apparently evolved independently in both groups. However, the presence of well‐developed maxillary and labial glands is arguably a retained groundplan feature of Coleoptera, with parallel loss in Archostemata, Adephaga and various groups of Polyphaga. J. Morphol. 277:615–633, 2016. © 2016 Wiley Periodicals, Inc.     

Head structures of Priacma serrata Leconte (Coleptera, Archostemata) inferred from X-ray tomography

Internal and external features of the head of Priacma serrata were studied with X-ray microtomography and with histological methods. The comparison of both techniques shows that X-ray tomography is a promising new technique for the investigation of insect anatomy. The still somewhat coarse resolution of the X-ray data is compensated for by advantages like the nondestructive and artifact-free data acquisition. The head of P. serrata and other adults of Archostemata is characterized by many derived features. Muscular features of Priacma, especially muscles of the labium and pharynx, differ strongly from what is found in other groups of Coleoptera. Several character states are considered as autapomorphies of Archostemata: scale-like surface structures, constricted neck, strongly reduced tentorium, and the plate-like, enlarged prementum. The scales provide a protecting surface pattern and may have evolved with a more exposed lifestyle. The enlarged prementum forms a lid, which closes the mouth and covers the ligula when it is pulled back by contraction of the unusually strong submento-premental muscle. The presence of four cone-shaped protuberances on the dorsal side of the head is considered an autapomorphy of Cupedidae. The galea with a narrow stalk and a round and pubescent distal galeomere is another autapomorphy of this family. It has probably evolved as an adaptation to pollen-feeding. The shape of the mandible of Cupedidae is plesiomorphic compared to what is found in adults of Ommatidae. The vertical arrangement of apical teeth is an autapomorphy of the latter family. The lateral insertion of the antenna in Priacma is a groundplan feature of Cupedidae. The dorsal shift is a synapomorphy of all other cupedid genera. A cladistic analysis of characters of the head and additional data resulted in the following branching pattern: ((Crowsoniella + (Omma + Tetraphalerus)) + (Micromalthus + (Priacma + (Paracupes + (Cupes + Tenomerga + Prolixocupes + Rhipsideigma + Distocupes + (Adinolepis + Ascioplaga)))))).     

Phylogenetic analysis of Trechitae (Coleoptera: Carabidae) based on larval morphology, with a description of first-instar Phrypeus and a key to genera

Abstract. Sixty-nine characters of larval structure of twenty-eight genera of the supertribe Trechitae (Coleoptera: Carabidae) were analysed phylogenetically. The monophyly of Trechitae is strongly supported with five unique synapomorphies. The monophyly of Zolini + Bembidiini + Pogonini is supported with two synapomorphies. We propose that the tribe Trechini is a sister group to them and its monophyly is supported with two unique synapomorphies. The inferred branching pattern of Trechini genera is (Perileptus + Thalassophilus) + (Amblystogenium + (Trechimorphus + (Trechus + Epaphius + Aepopsis + Trechisibus))); Perileptus is a member of Trechodina rather than Trechina. The monophyly of Zolini is not supported. The monophyly of Pogonini is supported with two unique synapomorphies; its sister group relationships remain obscure; the branching pattern of pogonine genera is (((Pogonus + Pogonistes) + Cardiaderus) + Thalassotrechus). No evidence for monophyly of the tribe Bembidiini (s. lato; including subtribes Bembidiina, Tachyina, Xystosomina, and Anillina) was found. The relationships of Phrypeus are obscure; no evidence could be found linking it with Bembidiina. Without Phrypeus, Bembidiina might be a monophylum with a single synapomorphy. Sinechostictus branches basal of (Bembidion + Asaphidion) and therefore should be treated as a separate genus. Tachyina and Xystosomina form a monophylum based on two unique synapomorphies; a close relationship with a monophyletic Anillina is suggested. Reduction of the number of claws from two to one in Trechitae has taken place twice: within Trechina (Trechus, Epaphius, Aepopsis and Trechisibus) and in (Zolini + Bembidiini + Pogonini). The previously unknown larvae of the isolated genus Phrypeus are described and illustrated. A key to all twenty-eight analysed Trechitae genera based on characters of larvae and a list of larval autapomorphies for each genus are provided.     

五种真蝽(Pentatoma Olivier) mtDNA-COII基因序列分析及系统发育关系初探(半翅目:蝽科)

测定并比较分析了真蝽属(Pentatoma)5种昆虫：褐真蝽P．semiannulata、斜纹真蝽P．illuminata、红足真蝽P．rufipes、H本真蝽P．japonica和金绿真蝽P．metallifera以及益蝽亚科2种外群种类(并蝽Pinthaeus humeralis和蠋蝽Arma custos)mtDNA—COII基因部分序列,依据分子数据建立了该5种昆虫的系统发育关系。结果显示,5种真蝽COII基因A T平均含量(73％)高丁弹尾目、缨尾目和直翅目昆虫,低于双翅目、鳞翅目及膜翅目昆虫,而与缨翅目的蓟马和半翅目的突角长蝽Oncopeltus fasciatus非常接近。系统发育结果显示,红足真蝽与日本真蝽亲缘关系最近,形成一个姊妹群,斜纹真蝽与金绿真蝽亲缘关系较近,也形成一个姊妹群,褐真蝽为较早分化的种类。     

Before the wasp-waist: comparative anatomy and phylogenetic implications of the skeleto-musculature of the thoraco-abdominal boundary region in basal Hymenoptera (Insecta)

The skeleto-musculature of the metathorax and first abdominal segment was studied in representatives from all ’symphytan’ families. Forty-three informative characters were coded and scored. The distribution of character states are discussed with reference to recent cladistic treatments of the Hymenoptera. Previously unreported autapomorphies for the Hymenoptera are the separation of the metathoracic trochantins from the metepisterna and metacoxae, the position of the metafurca anteriorly on the discrimenal lamella of the metathorax and the presence of second abdominal sternum (S2)-metacoxal muscles. The absence of metapleuro-S2 muscles is an autapomorphy for the non-xyelid Hymenoptera. Putative autapomorphies of the Tenthredinoidea are: (1) the presence of transverse metanotal muscles, (2) the subdivision of the second phragmo-third phragmal muscles, part of which arises from the metalaterophragmal lobes, (3) the posterior thoracic spiracle occlusor muscles arising from the mesepisterna, (4) the absence of trochantins and metanoto-trochantinal muscles and (5) the presence of elongate lateral metafurcal arms. Having the paracoxal sulci extending along the anterior margins of the metepisterna and the anterior metafurcal arms reduced are synapomorphies for all tenthredinoid families excluding Blasticotomidae. The presence of transversely extended cenchri with hooks on their entire surface is a putative synapomorphy for Diprionidae + Cimbicidae + Argidae + Pergidae. The clade Cimbicidae + Argidae + Pergidae is supported by the absence of metanoto- metabasalar muscles, the fusion of the first abdominal tergite (T1) with the metepimera and the absence of posterior metapleuro-metafurcal muscles. Autapomorphies of the Cimbicidae are the absence of the metalaterophragmal lobes and the metalaterophragmal-metafurcal muscles. Having the mesoscutello-metanotal muscle inserting on a projection from the anterior margin of the metanotum, surrounding the tendon with sclerotised cuticle, is a synapomorphy for the Argidae and Pergidae. Autapomorphies of the Cephoidea are the absence of cenchri, the presence of distinct articulations between T1 and the metepimera, and having the paracoxal sulci extending subparallel with the metafurcal discrimen. The monophyly of the Siricidae is supported by the absence of the anapleural clefts and the presence of an elongate mesospina projecting posteriorly between the anterior metafurcal arms. The presence of a membranous pouch ventrally of T1 and of large T1-metafurcal muscles is unique to Xiphydria camelus among the taxa examined. The absence of hind wing tegulae, posterior metapleuro-metafurcal, metanoto-trochantinal and anterior metanoto-metacoxal muscles, and the presence of elongate lateral metafurcal arms are synapomorphies for Xiphydriidae + Orussidae + Apocrita. The Orussidae greatly resembles the Apocrita in the region studied, a synapomorphy for the two taxa being the presence of metepisternal depressions. An autapomorphy for the Apocrita is the fusion of T1 with the metapleural arms; these structures closely abut in Orussidae. The fusion of T1 with the metepimera was preceded by the reduction of the posterior parts of the metepimera, as observed in Anaxyelidae, Xiphydriidae, and Orussidae. This makes the lines of fusion between T1 and the metepimera confluent with the metapleural sulci in the Apocrita. There is no compelling evidence for considering the configuration of T1 and the metepimera in Cephoidea to be incipient in the formation of the propodeum in Apocrita. The close association between the meso- and metathorax and the integration of T1 in the metathorax evolved gradually twice within the basal hymenopteran lineages, culminating in the Apocrita and the Cimbicidae + Argidae + Pergidae clade. Accepted: 2 September 1999     

Vergleichende Untersuchungen der kopfbewegenden Muskulatur bei Anoplura (Psocodea: Phthiraptera)

comparative investigations of the head moving muscles in Anoplura (Psocodea: Phthiraptera) The head moving muscles in different taxa of Anoplura were examined and compared with that in other groups of the Psocodea and the Pterygota. The ‘Grundplan’ fo the muscle arrangement in different groups of the Psocodea was reconstructed. This character complex supports the possibility that the Ischnosera + Anoplura dn the Ischnocera + Anoplura + Rhynchophthirina could be monophyletic groups within the Phthiraptera.     

On the phylogeny of the Arminidae (Gastropoda, Opisthobranchia, Nudibranchia) with considerations of biogeography

In the past, the different genera of the family Arminidae have been diagnosed (mostly) on the basis of plesiomorphic characters and therefore their monophyly is questionable. The Arminidae are characterized by the autapomorphies 'possession of marginal sacs' and 'rhinophores with longitudinal lamellae'. The genus Heterodoris is excluded from the family. Two possible hypotheses about the phylogenetic relationships within the Arminidae are presented.
The Arminidae probably originated in the western Pacific, near Japan and have distributed in a westerly direction. The most primitive species ( Dermatobranchus ) are restricted mainly to the western Pacific region while the more derived species ( Armina ) have a world-wide distribution.