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The gastropod infraclass Euthyneura comprises at least 30,000 species of snails and slugs, including nudibranch sea slugs, sea hares and garden snails, that flourish in various environments on earth. A unique morphological feature of Euthyneura is the presence of two pairs of sensory head tentacles with different shapes and functions: the anterior labial tentacles and the posterior rhinophores or eyestalks. Here we combine molecular phylogenetic and microanatomical evidence that suggests the two pairs of head tentacles have originated by splitting of the original single tentacle pair (with two parallel nerve cords in each tentacle) as seen in many other gastropods. Minute deep-sea snails of Tjaernoeia and Parvaplustrum, which in our phylogeny belonged to the euthyneurans’ sister group (new infraclass Mesoneura), have tentacles that are split along much of their lengths but associated nerves and epidermal sense organs are not as specialized as in Euthyneura. We suggest that further elaboration of cephalic sense organs in Euthyneura closely coincided with their ecological radiation and drastic modification of body plans. The monotypic family Parvaplustridae nov., superfamily Tjaernoeioidea nov. (Tjaernoeiidae + Parvaplustridae), and new major clade Tetratentaculata nov. (Mesoneura nov. + Euthyneura) are also proposed based on their phylogenetic relationships and shared morphological traits.

The bivalve mantle margin comprises the free portion of the pallial lobes, and often bears muscular, sensory or secretory structures located on extensions of the mantle, called mantle folds. In the bivalve Infraclass Pteriomorphia, which underwent an extensive adaptive radiation in epifaunal habitats, the mantle margin exhibits an enormous diversity in mantle fold organization and associated structures. The present work reviews the current knowledge of the mantle margin in Pteriomorphia and discusses how the mantle margin can be used as a model for investigating the evolution of the marine epifaunal benthos as many species in this community have undergone similar selective pressures and developed comparable morphological adaptations, such as ciliated tentacular organs. Herein, we stress how additional investigations are necessary to cover the huge diversity seen in this taxonomic group. Given the scarcity of broad comparative studies of bivalves, including Pteriomorphia, the homology of their pallial features is still not clear. Moreover, although it is suspected that mantle margin diversification is correlated with transitions in pteriomorphian life habits, no hypotheses have been tested within a phylogenetic framework. To address these questions requires extensive comparative analyses of mantle margin diversity in Pteriomorphia that focuses on: 1) genetic expression and molecular dynamics in the mantle margin; 2) mantle margin morphogenesis, 3) assessment and test of hypotheses on homology, convergent and parallel evolution of mantle margin characters, and 4) testing possible correlations between mantle margin morphological diversity and lifestyle transitions. In a broader sense, by using Pteriomorphia as a model clade, we will gain insight into the macroecology of the marine epifauna.

The infraclass Palaeognathae includes the flightless ratites (ostrich, emu, rhea, cassowary, kiwi) and the tinamous, a group of related, flighted birds. This chapter focuses on unique anatomy and important non-infectious and infectious diseases of these groups of birds. Notable among these are management-related diseases such as gastrointestinal tract impactions, OIE reportable viral diseases including those cause by the avian influenza and eastern equine encephalitis viruses, and a range of species-specific endo- and ectoparasites virus infections.

Background Runt-related transcription factor 2 (RUNX2) is a transcription factor essential for skeletal development. Variation within the RUNX2 polyglutamine / polyalanine (QA) repeat is correlated with facial length within orders of placental mammals and is suggested to be a major driver of craniofacial diversity. However, it is not known if this correlation exists outside of the placental mammals. Results Here we examined the correlation between the RUNX2 QA repeat ratio and facial length in the naturally evolving sister group to the placental mammals, the marsupials. Marsupials have a diverse range of facial lengths similar to that seen in placental mammals. Despite their diversity there was almost no variation seen in the RUNX2 QA repeat across individuals spanning the entire marsupial infraclass. The extreme conservation of the marsupial RUNX2 QA repeat indicates it is under strong purifying selection. Despite this, we observed an unexpectedly high level of repeat purity. Conclusions Unlike within orders of placental mammals, RUNX2 repeat variation cannot drive craniofacial diversity in marsupials. We propose conservation of the marsupial RUNX2 QA repeat is driven by the constraint of accelerated ossification of the anterior skeleton to facilitate life in the pouch. Thus, marsupials must utilize alternate pathways to placental mammals to drive craniofacial evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0955-6) contains supplementary material, which is available to authorized users.

A persistent controversy has concerned the identification of the factors that influence the quantitative variation in the physiological characters of species, an example of which is the basal rate of metabolism of endotherms. The most important factor accounting for its variation is body mass as long as the range in mass is appreciable. But mass never accounts for all of the variation and none if species have the same mass. Most of the residual variation around the mass curve is associated with behavioral characters, ecological factors, and phylogeny, i.e., history. These agents influence energy expenditure by different means and at different stages in the life history of species. Phylogeny describes the historic origin, evolution, and distribution of character states in contemporary species. However, the level of energy expenditure is quantitatively determined by the collective of realized states in combination with conditions in the environment. Therefore, two stages determine energy expenditure: (1) the evolution of character states and (2) their impact in conjunction with conditions on the environment. Behavioral characters and ecological factors, when coupled with log10 mass, usually account for94 % of the variation in the log10 basal rates of birds and mammals, a capacity not found in phylogenetic analyses. The difficulty of determining a direct impact of phylogeny on physiological characters results from its correlation with behavioral characters. When appropriate, the passerine/non-passerine dichotomy in birds and the sub/infraclass dichotomy in mammals combine with behavioral characters, ecological factors, and log10 mass to increase r (2) to account for 96-99 % of the variation in log10 basal rate. This occurs because dichotomies incorporate factors other than those already in the analyses. The clearest demonstration of the direct impact of character states is the equality of energy expenditure in species convergent with species from other clades without any evidence of the clade to which the species belong. A multifactorial approach depends on the inclusion of life history characteristics of species, but this analysis applies only to continuous, quantitative relationships, which are often modified by discontinuous agents. Distinctive character states distinguish species and therefore must be included in any attempt to account for differences in their level of energy expenditure. No analysis that ignores life history characteristics can account for the quantitative variation in energy expenditure beyond that associated with body mass.

Paraulacus sinicus Ping, 1928 was originally assigned to Aulacidae (Hymenoptera, Evanioidea), later transferred to Mesoserphidae (Hymenoptera, Proctotrupoidea), and even considered as order incertae sedis in the infraclass Neoptera. Re-description of the holotype indicates that the species should be attributed to either Mesoserphidae or Roproniidae in the Proctotrupoidea, a superfamily of parasitoid wasps. The species is considered to have been collected from the Middle Jurassic Haifanggou Formation and not from the Lower Cretaceous as in the original description.

The two LTR retrotransposon-derived genes PEG10 and PEG11/RTL1 play essential roles in placental formation and its maintenance in the current mammalian developmental system. The former is a therian-specific and the latter is a eutherian-specific gene, suggesting that once they had been acquired in common ancestors of the therian and eutherian mammals, respectively, they have underwent positive selection during the course of mammalian evolution due to developmental advantages they conferred. Thus, their exaptation had a profound impact on the evolution of mammalian viviparity as well as the emergence of the therians and eutherians, the infraclass and subclass of mammals, respectively. How the exaptation of PEG10 and PEG11/RTL1 come to take place in the mammalian lineage? We propose that the exaptaion mechanism comprises two subsequent steps. The first follows the pattern of nearly neutral theory of molecular evolution, where the retrotransposons were neutralized by DNA methylation and genetic dri...

were excludedfrom this group, the concept of the taxon Eutriconodonta [1], which corresponds to the infraclass Triconodonta sensu stricto [2], was established. The heterogeneity of this taxon is evident from some characters of this group, including the familiesAmphilestidae and Gobiconodontidae (Repenomamidae) [3, 4]. Phylogenetic analysis corroborated thatAmphilestidae and Gobiconodontidae are closer toancestors of therian mammals than Triconodontidae[5] and suggested the paraphyletic origin of Amphilestidae [5, 6], which is regarded as a key group for theunderstanding of dental evolution of Mesozoic mammals. Therefore, Mesozoic mammal groups with tricuspid teeth are frequently combined under the informal name “triconodont mammals” [5–7].In the present study, a new triconodont mammalfrom the Early Cretaceous Shestakovo 1 locality inWestern Siberia is described. The material was collected by E.N. Maschenko in 2009; it is housed in theBorissiak Paleontological Institute of the RussianAcademy of Sciences, Moscow (PIN).

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.

We have sequenced and characterized the complete mitochondrial genome of the soft-shell clam, Mya arenaria, an important organism for environmental toxicology and aquaculture. Mya arenaria is located in the taxonomic order Myoida, which lacks any member with a completely annotated mitogenome. The M. arenaria mitochondrial genome is 17 947 bp in length. Like most marine bivalves, the circular mitogenome codes entirely on the heavy strand, with no introns. As with other bivalves, the gene order of the mitochondrion is highly rearranged. The mitogenome contains 12 protein-coding genes but ATP8 is missing, consistent with about half of all bivalve genera. Twenty-three tRNAs were identified. Phylogenetic analysis shows that M. arenaria is related most closely with the bivalves Sinonovacula constricta, and Moerella iridescens, of the infraclass Euheterodonta (unassigned). This, along with the close grouping of the phylogenetic trees, confirms a close tie between Myoida and Euheterodonta (unassigned).

New taxa of uncertain position within the infraclass Polyneoptera (Gryllomantidae fam. nov.: Gryllomantis gen. nov., Lower Cretaceous; Mantoblattidae fam. nov.: Mantoblatta mira gen. et sp. nov., Upper Cretaceous) and within the order Dictyoptera (Pseudojantaropterix gen. nov., Lower Cretaceous) are described. The superfamily Umenocoleoidea of uncertain position within the latter order is discussed on the basis of new information on Jantarimantidae and some other Cretaceous Dictyoptera.

The review is devoted to research history and to the morphological description of the infraclass Facetotecta Grygier, 1985—the mysterious group of marine organisms. Its naupliar instars are characterized by headshield ornamentation made of cuticular plates of various sizes. The name of these crustaceans originates from the carapace sculpture. Facetotectan life cycle is incompletely studied, since only larval stages are described.

Since a fourth MSH sequence, delta-MSH, has been detected in the proopiomelanocortin (POMC) gene of a dogfish and a stingray, members of superorder Squalea (class Chondrichthyes), it is possible that this novel MSH sequence might be a feature common to the POMC genes of all modern sharks and rays. As an initial step towards addressing this question, a full-length POMC cDNA was cloned and sequenced from the pituitary of the Port Jackson shark, Heterodontus portusjacksoni. The Port Jackson shark represents one of the oldest lineages in superorder Galea, and this superorder together with superorder Squalea form infraclass Neoselachii (the extant sharks and rays). The Port Jackson shark POMC cDNA has an open reading frame that is 1032 nucleotides in length and encodes the deduced amino acids sequences for beta-endorphin, ACTH/alpha-MSH, beta-MSH, gamma-MSH, and delta-MSH. Port Jackson shark delta-MSH has 83% primary sequence identity with dogfish and stingray delta-MSH, and it appears that the delta-MSH sequence may have been the result of an internal domain duplication and reinsertion of the beta-MSH sequence. The presence of the delta-MSH sequence in the POMC genes of representatives of both superorders of infraclass Neoselachii would indicate that the delta-MSH sequence must have been present in the ancestral euselachian shark that gave rise to the neoselachian radiation.

We sequenced exon 6 of the nuclear dentin matrix protein 1 (DMP1) gene from 19 species of bats (order Chiroptera) to assess the utility of this gene for higher-level phylogenetic studies. Bayesian analysis revealed high support (posterior probabilities >/=0.95) for monophyly of Noctilionoidea (Phyllostomidae, Noctilionidae, and Mormoopidae), all genera and most families examined. Comparison of the phylogenetic information present in DMP1 with mitochondrial rDNA and nuclear RAG2 genes indicated no significant heterogeneity. Thus, we concatenated these three data sets into a single "total evidence" phylogenetic analysis. Combined analysis was congruent with study of RAG2 and combined RAG2 and mtrDNA sequences, but improved support (Bayesian posterior probabilities) for many nodes. Our results indicate that exon 6 of DMP1 is rapidly evolving, able to tolerate non-frame shifting insertion and deletion events, is more variable than RAG2, and provides phylogenetic resolution from the interfamilial to infraclass levels in mammals.

In this review, we present an overview of the recent advances of genomic technologies applied to studies of fish species belonging to the superclass of Osteichthyes (bony fish) with a major emphasis on the infraclass of Teleostei, also called teleosts. This superclass that represents more than 50% of all known vertebrate species has gained considerable attention from genome researchers in the last decade. We discuss many examples that demonstrate that this highly deserved attention is currently leading to new opportunities for answering important biological questions on gene function and evolutionary processes. In addition to giving an overview of the technologies that have been applied for studying various fish species we put the recent advances in genome research on the model species zebrafish and medaka in the context of its impact for studies of all fish of the superclass of Osteichthyes. We thereby want to illustrate how the combined value of research on model species together with a broad angle perspective on all bony fish species will have a huge impact on research in all fields of fundamental science and will speed up applications in many societally important areas such as the development of new medicines, toxicology test systems, environmental sensing systems and sustainable aquaculture strategies.

The first studies relating to classification of creatures had been done in 18th century, by Carl Linnaeus (1) Linnaeus had been regarded as the father of morphologic classification (taxonomy). The creatures have been classified according to similarity of their appearances, in the morphologic classification. For instance; a shark that is a kind of fish and a dolphin that is a kind of mammalia had been examined within the scope of same family, although they are not similar as genetic structure. Flying squirrel (tribe of pteromyini) and Petaurus breviceps are very similar to each other with their big eyes, the white bellies and the stiff integument segment that takes place between their arm and legs and provides soaring and keeping the balance; therefore, they have been regarded as close relatives. However, the flying squirrel is a placental mammal (infraclass eutheria) and the Petaurus breviceps is a pouched mammal (infraclass marsupialia). Although they are different originally, there are creatures that appear differently even though they are similar genetically on the contrary the creatures that appear similar. Consequently, some bird species that have different appearances of cock and hen (for instance, Agelaius phoenicus) have been defined as different species by misunderstanding their physical appearances (2).

Perhaps the most striking fact about early Cenozoic avian history some 70 million years ago was the rapid radiation of large, flightless, ground-living birds. It has been suggested that, for a time, there was active competition between these large terrestrial birds and the early mammals. Probably reflecting the above noted early start of Ratitae of the infraclass Eoaves , the presumptive sex chromosomes of their present day survivors, such as the emu and the ostrich, largely remained homomorphic. The signs of genetic differentiation between their still-homomorphic Z and W chromosomes were tested by using two marker genes (Z-linked ZOV3 and the gene for the iron-responsive element-binding protein) and one marker sequence of a part of a presumptive pseudogene (W-linked EE0.6 of the chicken). Their homologues, maintaining 71–92% identities to the chicken counterparts, were found in both the emu ( Dromaius novaehollandiae ) and the ostrich ( Struthio camelus ). Their locations were visualized on chromosome preparations by fluorescence in situ hybridization. In the case of the emu, these three marker sequences were localized on both members of the fifth pair of a female, thus revealing no sign yet of genetic differentiation between the Z and the W. The finding was the same with regard to both members of the fourth pair of male ostriches. In the female ostrich, however, the sequence of the gene for the iron-responsive element-binding protein was missing from one of the pairs, thus revealing the differentiation by a small deletion of the W from the Z.

Nauplii V of the rare crustacean Hansenocaris furcifera Ito, 1989, belonging to the infraclass Facetotecta were recorded in the plankton of Peter the Great Bay (Sea of Japan) for the first time. The larvae were probably transported in summer from the coastal waters off Japan. Scanning electron microscopic observations revealed previously unknown morphological characteristics of these larvae: three pairs of pore fields on the dorsal side of the carapace and the presence of processes covered with thickened setae and located at the base of mandibles.

A small, well-preserved dentary of a tribosphenic mammal with the most posterior premolar and all three molars in place has been found in Aptian (Early Cretaceous) rocks of southeastern Australia. In most respects, dental and mandibular anatomy of the specimen is similar to that of primitive placental mammals. With the possible exception of a single tooth reported as Eocene in age, terrestrial placentals are otherwise unknown in Australia until the Pliocene. This possible Australian placental is similar in age to Prokennalestes from the late Aptian/early Albian Khoboor Beds of Mongolia, the oldest currently accepted member of the infraclass Placentalia.

The genetic basis for different host plant use was studied in a herbivorous ladybird beetle, Epilachna pustulosa, that exhibits interpopulational variation in host plant utilization. It usually depends on thistle, but one of the local forms occurs on both thistle and blue cohosh, which differ at the infraclass taxonomic level. In this local population, genetic association between the developmental performance on the two plants was neutral, suggesting genetic independence across the host plants. The form of reaction norms indicated some changes in relative rank position. Genetic variation among individuals on each host plant was detected. These results suggest that different genotypes are selected on different host plants and that a substantial proportion of the overall phenotypic plasticity is contributed by genotype-dependent environmental effects.

The four orders of eutherian mammals which are traditionally placed in the superorder Archonta [Chiroptera (microbats and megabats), Dermoptera (flying lemurs), Primates (primates), and Scandentia (tree shrews)] are among the best-studied taxa of their infraclass from both the molecular and morphological perspectives. Nevertheless, the ordinal relationships of archontans remain unresolved. While morphological studies favor their monophyly, molecular investigations do not. To evaluate these opposing conclusions, parsimony analyses were conducted with three separate sets of DNA sequences from both the nuclear and mitochondrial genomes and one file of morphological data for archontans and other eutherian mammals. Statistical tests of character support and ordinal branching pattern differences documented that the three sets of DNA sequences and their results were homogeneous and congruent, thereby allowing for the combination of these data into one large matrix for further phylogenetic analysis. In contrast, these same tests revealed that the combined sequence and morphological files and their topologies were in strong conflict. Archontan monophyly was supported by the morphological evidence, but this arrangement was strongly rejected by the combined DNA sequences that favored instead a grouping of Dermoptera, Primates, and Scandentia with Lagomorpha (rabbits) and Rodentia (rodents). Resolution of these significant differences will require further evaluations about the homologies and evolutionary properties of the molecular and morphological characters and about the appropriateness of the chosen phylogenetic methods, as well as the incorporation of new comparative data from both sources.

For almost a century, the American Psychiatric Association has improved psychiatric practice via its diagnostic manual series. However, the increasing number of diagnoses has created predicaments for clinicians and society. This report suggests explanations for this "inflation" and, using systematics, proposes the following five linked strategies for improving our diagnostic schema. First, criteria based on purposes underlying diagnosis should form the basis for including and excluding psychiatric diagnoses. Second, the major categories (or classes) should be reduced from 17 to one half to one third that number. Third, many psychiatric diagnoses should be removed from their current status as independent diagnoses (or subclasses) and relegated to a more specific taxonomic stratum (e.g., infraclass). Fourth, promising information for new or modified taxons would compose a fourth stratum (or parvclass). Fifth, comorbidity would become a more useful concept if defined as major, intermediate, and minor comorbidity, occurring at class, subclass, and infraclass levels.

Reconstruction of the phylogeny of the five extant classes of the phylum Echinodermata has proven difficult. Results concerning higher-level taxonomic relationships among echinoderms are sensitive to the choice of analytical parameters and methods. Moreover, the proposal of a putative sixth class based on a small enigmatic disc-shaped echinoderm, Xyloplax, from the deep seas of the Bahamas and New Zealand in the 1980s further complicated the problem. Although clearly an echinoderm, Xyloplax did not have clear affinity among known groups. Using molecular sequence and developmental data from recently collected Xyloplax adults and embryos, we show that rather than representing an ancient distinct lineage as implied by its status as a class, Xyloplax is simply a starfish that is closely related to the asteroid family Pterasteridae. Many members of the Pterasteridae and all Xyloplax inhabit deep or polar seas and brood young. Brooding pterasterids and Xyloplax hold their young in specialized adult chambers until the young reach an advanced juvenile stage after which they are released as free-living individuals. We hypothesize that the unique morphology of Xyloplax evolved via progenesis--the truncation of somatic growth at a juvenile body plan but with gonadal growth to maturity. Although the overall phylogeny of extant echinoderms remains sensitive to the choice of analytical methods, the placement of Xyloplax as sister to pterasterid asteroids is unequivocal. Based on this, we argue that the proposed class and infraclass status of Xyloplax should be suppressed.

Alexarasniidae fam. n. and Alexarasnia rossica gen. et sp. n. are described from the Upper Permian of European Russia. Systematic position of this enigmatic family within the infraclass Polyneoptera is unclear.

The resolution of the problem of ichthyosaurian affinities has been complicated and prolonged by an emphasis on the morphology of Jurassic ichthyosaurs, some 30 to 40 m.y. younger than the earliest known species. Morphology of the skull and axial skeleton of Triassic ichthyosaurs is the key to resolving the problem. The ichthyosaurs are included here in the Subclass Diapsida on the basis of skull roof and palatal features. Within the Diapsida, ichthyosaurs appear to be most closely related to the Younginiformes of the Infraclass Lepidosauromorpha, with which they may have shared a common ancestor. Triassic ichthyosaurs were considerably different ecologically from their Jurassic descendants. Many Triassic ichthyosaurs were longer bodied and had long, broad tails in contrast to the deep, streamlined bodies and lunate tails of Jurassic species. As a result, Triassic ichthyosaurs probably tended to be ambush predators, whereas Jurassic ichthyosaurs were mainly pursuit predators. Early ichthyosaurs may have been more generalized in their prey preference, as suggested by heterodonty in many Early and Middle Triassic species.

Analysis of a comprehensive dataset demonstrates that the brachial index (BI = humerus length/ulna length) of modern birds (Neornithes) varies significantly between clades at all taxonomic levels, yet is strongly correlated with recent phylogenetic hypotheses. Variance in BI at the infraclass level is low, but increases rapidly during the proposed major radiation of neornithines in the Palaeocene and Eocene. Although a BI of greater than 1 is primitive for Neornithes, more basal groups of Mesozoic birds (Confuciusornithidae and some members of the diverse Enantiornithidae) had BIs comparable with those of 'higher' modern clades. It is possible that occupation of ecological niches by these Mesozoic clades precluded the divergence of some groups of neornithines until after the Cretaceous-Tertiary boundary. We suggest that with further analysis and data collection the relationships between flight behaviour, ecology and BI can be determined. Hence, BI may provide a useful tool for characterizing the ecology of fossil birds.

Eight family-group names of the insect orders Orthoptera and Titanoptera (Leiomelinae, Tettohaglinae, Praelocustopsinae, Archelcaninae, Subtiloriini, Prolandrevini, Prototitaninae, Deinotitaninae) published without concrete indications of their type genus are unavailable in according to the International Code of Zoological Nomenclature. They are made available here.

The generic names Sharovoplana nom. n., Baisoxya nom. n., Triassaga nom. n., and the subfamily name Triassaginae nom. n. are proposed for, respectively, Paraplana Sharov, Monodactylus Sharov, Maraga Gorochov, and Maraginae Gorochov because of homonymy. New synonymy among the replacement names is established: Kashgarlimahmutia Kocak et Kemal = Ademirsoyus Ozdikmen, syn. n.; Kashgarlimahmutiinae Kocak et Kemal = Ademirsoyinae Ozdikmem, syn. n.

A new therian mammal of primitive tribosphenic grade is described from the Upper Milk River Formation (Upper Cretaceous) of Alberta, Canada, and its relationships to other primitive tribosphenic therians are discussed. The new therian and its presumed nearest relatives form the basis of a new family within the Order Aegialodontia. A revised classification of the Infraclass Tribotheria is presented.

The skeleton of a long-ribbed reptile from the Upper Permian Marl Slate of north-east England is described. The animal is assigned to the genus Weigeltisaurus, previously recorded from the Kupferschiefer of West Germany. Long-ribbed reptiles from the Upper Permian of Madagascar are also considered. Daedalosaurus Carroll, 1978 is a junior synonym of Coelurosauravus Piveteau, 1926. The European and Madagascan genera can be accommodated within a single family Coelurosauravidae, Infraclass Eosuchia. The skull is diapsid with an incomplete lower temporal arcade. Comparison with the modern Draco and the Upper Triassic kuehneosaurids supports the conclusion that the coelurosauravids were effective gliders.

On the basis of a unique specialization of the braincase the four nontherian orders of mammals—the living Monotremata and the extinct Tricono-donta, Docodonta, and Multituberculata—are united into a single subclass, Prototheria. The Triconodonta and Docodonta are closely related and are grouped together in the infraclass Eotheria. The Monotremata and Multituberculata are only remotely allied to all other mammals and are each placed in a separate infraclass—Ornithodelphia for the monotremes and Allotheria for the Multituberculates. A classification of prototherian mammals to family is presented.

The Ginglymodi are a group of ray-finned fishes that make up one of three major subdivisions of the infraclass Neopterygii. Extant ginglymodians are represented by gars, which inhabit freshwater environments of North and Central America and Cuba. Here, we report the discovery of well-preserved fossils of a new ginglymodian, Kyphosichthys grandei gen. et sp. nov., from the Middle Triassic (Anisian) marine deposits (Guanling Formation) in Luoping, eastern Yunnan Province, China. The discovery documents the first known fossil record of highly deep-bodied ginglymodians, adding new information on the early morphological diversity of this group. The studies of functional morphology of extant deep-bodied fishes indicate that Kyphosichthys is not a fast swimmer but has a good performance in precise maneuvering, representing a morphological adaptation to structurally complex habitats (e.g. thick macrophyte beds, rocky areas, or coral reefs), which differs from the other members of this group. A cladistic analysis with the new fish taxon included supports the hypothesis that the Ginglymodi are more closely related to the Halecomorphi than to the Teleostei. Represented by Felberia, Kyphosichthys, and Dapedium, a highly deep and short fish body type has independently evolved at least three times in the stem-group neopterygians, ginglymodians, and basal teleosts within the lower neopterygians of the Triassic.

Available evidence provides little support for a recent proposal that the term "trophoblast" be applied solely to eutherian mammals. Arguments for such a restricted usage are based on a dichotomous interpretation of therian reproduction that underestimates the developmental, structural, and functional diversity of trophoblastic tissues occurring within the infraclass Eutherian. The occurrence of developmental patterns that are phenotypically intermediate between those of commonly studied eutherians and metatherians suggests that blastocyst development is not fundamentally different in marsupials and eutherians. The trophoblast of marsupials accomplishes most or all of the major functions of the eutherian trophoblast, including maternal-fetal physiological exchange, implantation, contribution to placental membranes, steroid metabolism, and possibly, immunological protection of the conceptus. Furthermore, application of the term "trophoblast" to marsupials is consistent with present and past usage, as well as with the original definition and etymological derivation of the term. Therefore, we recommend that the term "trophoblast" continue to be applied in a functional-morphological sense to the appropriate extraembryonic tissues of marsupials. Such use of functional (rather than taxonomic) criteria for application of this term avoids biasing interpretations of mammalian reproductive evolution.

The Polypteridae, sole representative family of the Cladistia, cannot be considered as living fossils on the basis of their inadequate paleontoogical record. Rather, their claim to that status lies in their having retained a great number of the primitive features lost by other extant members of the Actinopterygii (Rosen et al. 1981). Polypterus and Erpetoichthys are classified as follows: class: Osteichthyes; subclass: Actinopterygii; infraclass: Cladistia; order: Polypteriformes; family: Polypteridae.