Non-monophyly of most supraspecific taxa of calcareous sponges (Porifera, Calcarea) revealed by increased taxon sampling and partitioned Bayesian analysis of ribosomal DNA

Calcareous sponges (Porifera, Calcarea) play an important role for our understanding of early metazoan evolution, since several molecular studies suggested their closer relationship to Eumetazoa than to the other two sponge 'classes,' Demospongiae and Hexactinellida. The division of Calcarea into the subtaxa Calcinea and Calcaronea is well established by now, but their internal relationships remain largely unresolved. Here, we estimate phylogenetic relationships within Calcarea in a Bayesian framework, using full-length 18S and partial 28S ribosomal DNA sequences. Both genes were analyzed separately and in combination and were further partitioned by stem and loop regions, the former being modelled to take non-independence of paired sites into account. By substantially increasing taxon sampling, we show that most of the traditionally recognized supraspecific taxa within Calcinea and Calcaronea are not monophyletic, challenging the existing classification system, while monophyly of Calcinea and Calcaronea is again highly supported.     

Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea)

Calcareous sponges (Phylum Porifera, Class Calcarea) are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU) rDNA and the almost complete large subunit (LSU) rDNA of additional key species and complemented this dataset by substantially increasing the length of available LSU sequences. Phylogenetic analyses provided new hypotheses about the relationships of Calcarea and about the evolution of certain morphological characters. We tested our phylogeny against competing phylogenetic hypotheses presented by previous classification systems. Our data reject the current order-level classification by again finding non-monophyletic Leucosolenida, Clathrinida and Murrayonida. In the subclass Calcinea, we recovered a clade that includes all species with a cortex, which is largely consistent with the previously proposed order Leucettida. Other orders that had been rejected in the current system were not found, but could not be rejected in our tests either. We found several additional families and genera polyphyletic: the families Leucascidae and Leucaltidae and the genus Leucetta in Calcinea, and in Calcaronea the family Amphoriscidae and the genus Ute. Our phylogeny also provided support for the vaguely suspected close relationship of several members of Grantiidae with giantortical diactines to members of Heteropiidae. Similarly, our analyses revealed several unexpected affinities, such as a sister group relationship between Leucettusa (Leucaltidae) and Leucettidae and between Leucascandra (Jenkinidae) and Sycon carteri (Sycettidae). According to our results, the taxonomy of Calcarea is in desperate need of a thorough revision, which cannot be achieved by considering morphology alone or relying on a taxon sampling based on the current classification below the subclass level.     

The choanoderm of Sycettusa hastifera (Calcarea,Porifera) is able to generate new individuals

One of the main characteristics of sponges is their capacity for cell dedifferentiation. This capability can allow an impressive amount of asexual reproduction in these animals, because they are able to develop new individuals from just a few somatic cells. Studies of dedifferentiation, however, have focused mainly on sponges of the class Demospongiae. Therefore, we investigated here whether individuals of three different species of Calcarea are able to reconstitute new individuals following artificial fragmentation. We observed that fragmentation releases clumps of choanoderm able to initiate somatic embryogenesis. In Borojevia brasiliensis (asconoid aquiferous system, subclass Calcinea) and Paraleucilla magna (leuconoid aquiferous system, subclass Calcaronea), these clumps started to develop, but they did not pass through the first developmental phases. In Sycettusa hastifera (syconoid aquiferous system, subclass Calcaronea), the choanoderm was reorganized into primmorphs that fused to each other and formed an exopinacoderm. The first primmorphs’ spicules were triactines. Despite a large mortality rate, the primmorphs developed into olynthus stages. The somatic embryogenesis and the metamorphosis of the olynthus were similar to those observed during the sexual development of this and other calcareous sponge species. Our results show that in S. hastifera, and perhaps in other syconoid calcareous sponges, somatic embryogenesis occurs mainly from choanocytes, at least in vitro. However, primmorph development does not follow the same pattern observed in post‐metamorphic sexual development, as in that case diactines are always the first spicules to be synthesized in calcaronean species.     

The sterols of calcareous sponges (Calcarea, Porifera)

Sponges are sessile suspension-feeding organisms whose internal phylogenetic relationships are still the subject of intense debate. Sterols may have the potential to be used as independent markers to test phylogenetic hypotheses. Twenty representative specimens of calcareous sponges (class Calcarea, phylum Porifera) with a broad coverage within both subclasses Calcinea and Calcaronea were analysed for their sterol content. Two major pseudohomologous series were found, accompanied by some additional sterols. The first series encompassing conventional C(27) to C(29)Delta(5,7,22) sterols represented the major sterols, with ergosterol (ergosta-5,7,22-trien-3beta-ol, C(28)Delta(5,7,22)) being most prominent in many species. The second series consisted of unusual C(27) to C(29)Delta(5,7,9(11),22) sterols. Cholesterol occurred sporadically, mostly in trace amounts. The sterol patterns did not resolve intraclass phylogenetic relationships, namely the distinction between the subclasses, Calcinea and Calcaronea. This pointed towards major calcarean lipid traits being established prior to the separation of subclasses. Furthermore, calcarean sterol patterns clearly differ from those found in Hexactinellida, whereas partial overlap occurred with some Demospongiae. Hence, sterols only partly reflect the phylogenetic separation of Calcarea from both of the other poriferan classes that was proposed by recent molecular work and fatty acid analyses.     

Phylogenetic relationships of antlered flies, Phytalmia Gerstaecker (Diptera: Tephritidae): the evolution of antler shape and mating behaviour

Abstract  The genus Phytalmia (antlered flies, Diptera: Tephritidae) contains remarkable flies with elaborate male head projections known as antlers. The antlers are used in antagonistic intraspecific interactions between males competing to occupy oviposition sites. Phylogenetic relationships between the seven known species of Phytalmia were chosen to be investigated in order to determine the current monophyly of the genus and to assess the evolution of secondary sexual characters and associated behaviours, especially male antlers, fore-femoral, spines and stilting. A phylogenetic analysis of Phytalmia was conducted using two closely related species from the same tribe (Phytalmiini): Sessilina nigrilinea (Walker) and Diplochorda minor Malloch, and one species from a different tribe (Dacini): the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) as outgroups. A total of 1259 base pairs of mitochondrial DNA (COII and 16S) and 35 morphological characters were included in the analysis, using parsimony and maximum likelihood inference methods. A phylogenetic tree generated from combined data was used to infer the evolution of antler shapes and associated behaviours in the genus. The results of this paper support the monophyly of Phytalmia , with P. cervicornis Gerstaecker the sister group of the remaining species. The phylogeny suggests a general decrease in antler complexity over evolutionary time; however, the behavioural sequence of male flies becomes more complex over time, with steps (e.g. stilting) being added to the repertoire during antagonistic encounters. Finally, there are strong correlations between functionally constrained morphological and behavioural characters, therefore allowing the authors to make predications for species whose behaviours are unknown based on morphological attributes and the authors' hypothesised evolution of Phytalmia .     

Morphology,molecules, and the phylogenetics of cetaceans

Recent phylogenetic analyses of cetacean relationships based on DNA sequence data have challenged the traditional view that baleen whales (Mysticeti) and toothed whales (Odontoceti) are each monophyletic, arguing instead that baleen whales are the sister group of the odontocete family Physeteridae (sperm whales). We reexamined this issue in light of a morphological data set composed of 207 characters and molecular data sets of published 12S, 16S, and cytochrome b mitochondrial DNA sequences. We reach four primary conclusions: (1) Our morphological data set strongly supports the traditional view of odontocete monophyly; (2) the unrooted molecular and morphological trees are very similar, and most of the conflict results from alternative rooting positions; (3) the rooting position of the molecular tree is sensitive to choice of artiodactyls outgroup taxa and the treatment of two small but ambiguously aligned regions of the 12S and 16S sequences, whereas the morphological root is strongly supported; and (4) combined analyses of the morphological and molecular data provide a well-supported phylogenetic estimate consistent with that based on the morphological data alone (and the traditional view of toothed-whale monophyly) but with increased bootstrap support at nearly every node of the tree.     

Molecular systematics of Scaphirhynchinae: an assessment of North American and Central Asian Freshwater Sturgeon Species

The sturgeon subfamily Scaphirhynchinae contains two genera of obligate freshwater sturgeon: Scaphirhynchus and Pseudoscaphirhynchus, from North America and Central Asia, respectively. Both genera contain morphologically variable species. A novel data set containing multiple individuals representing four diagnosable morphological variants for two species of Pseudoscaphirhynchus, P. hermanni and P. kaufmanni, was generated. These data were used to test taxonomic hypotheses of monophyly for the subfamily Scaphirhynchinae, monophyly of both Scaphirhynchus and Pseudoscaphirhynchus, monophyly of P. hermanni and P. kaufmanni, and monophyly of the recognized morphological variants. Monophyly of the subfamily Scaphirhynchinae is consistently rejected by all phylogenetic reconstruction methodologies with the molecular character set while monophyly of both river sturgeon genera is robustly supported. The molecular data set also rejects hypotheses of monophyly for sampled species of Pseudoscaphirhynchus as well as monophyly for the recognized intraspecific morphological variants. Interestingly both Scaphirhynchus and Pseudoscaphirhynchus demonstrate the same general pattern in reconstructed topologies; a lack of phylogenetic structure in the clade with respect to recognized diversity. Despite rejection of monophyly for the subfamily Scaphirhynchinae with molecular data, reconstructed hypotheses from morphological character sets consistently support monophyly for this subfamily. Disparities among the data sets, as well as reasons for rejection of monophyly for Scaphirhynchinae and species of Scaphirhynchus and Pseudoscaphirhynchus with molecular characters are examined and a decreased rate of molecular evolution is found to be most consistent with the data.     

Is morphology telling the truth about the evolution of the species rich genus Peperomia (Piperaceae)?

Peperomia is with approximately 1,600 species one of the species rich angiosperm genera. Several characters on which current infrageneric classifications are based are influenced by parallel evolution. A well-resolved molecular backbone phylogeny of the genus is needed to address evolutionary questions about morphological traits. Based on separate and combined analyses of a morphological data set and three molecular data sets, phylogenetic relationships within Peperomia are investigated with respect to character evolution. The resulting trees from different datasets are highly congruent. Morphological characters are mapped on a combined molecular tree, visualizing the contrast between previously used homoplastic characters and some newly observed characters, that can be used to delimit monophyletic groups. Length mutational events of the chloroplast dataset are coded and plotted on the respective tree, to test if indels support alternative hypothesis of relationships found in the nuclear datasets as well as the overall performance of indels compared with substitutional mutations. Our findings indicate that length distribution of indels is highest among five and six bp events. Autapomorphic and synapomorphic length mutations are most frequent in both insertions and deletions and are also more frequent independent of the length of the mutation. Concluding, independent of the length, mutations are of phylogenetic importance and should not be disregarded. None of the homoplastic indels turn into synapomorphic indels, supporting the different topology of the nrDNA tree but indicate areas of molecular evolution in favour of length mutations resulting in independent events.     

Phylogenetic analysis of the Hsp70 sequences reveals the monophyly of Metazoa and specific phylogenetic relationships between animals and fungi

To understand the early evolution of the Metazoa, it is necessary to determine the correct phylogenetic status of diploblastic animals. Despite cladistic studies of morphological characters and recent molecular phylogenetic studies, it remains uncertain whether diploblasts are monophyletic or paraphyletic, and how the phyla of diploblasts are phylogenetically related. The heat shock protein 70 (Hsp70) sequences, because of their ubiquity and high degree of conservation, could provide a useful model for phylogenetic analysis. We have sequenced almost the entire nucleic acid sequence of cytoplasmic Hsp70 from eight diploblastic species. Our data support the monophyly of diploblastic animals. However, the phylogenetic relationships of the diploblast groups were not significantly resolved. Our phylogenetic trees also support the monophyly of Metazoa with high bootstrap values, indicating that animals form an extremely robust clade.      

Phylogeny and biogeography of the extant species of triplespine fishes (Triacanthidae, Tetraodontiformes)

A new phylogenetic hypothesis for the living species of triplespine fishes of the Indo-Western Pacific family Triacanthidae (Tetraodontiformes, Teleostei) is proposed. A data set of 55 morphological characters (34 osteological and 21 morphometric) was constructed. A cladistic analysis of the osteological data set yielded a single most-parsimonious tree. This cladogram does not support the monophyly of one of the four genera, Tripodichthys , but Bremer values for this analysis are low. The osteological data set was then combined with a data set of 21 morphometric characters that had previously been used to diagnose the four genera. The analysis of the combined data set produced the same phylogenetic hypothesis, but with greater nodal support. The biogeographical distribution of the living species is then interpreted with the use of this new phylogenetic information.     

Evolution of a mitochondrial cytochrome b gene sequence in the species-rich genus sebastes (Teleostei, Scorpaenidae) and its utility in testing the monophyly of the subgenus Sebastomus

The ecologically diverse and species-rich rockfishes (Sebastes) are a useful group for the study of marine speciation. The monophyly of the genus is generally accepted, as is the validity of most of the numerous species found along the West Coast of North America. However, the subgeneric groupings that would help in the proposal and interpretation of various speciation schemes are poorly supported based on widely overlapping morphological characters. The use of genetic characters provides an alternative approach. In this study, we present the first quantitative analysis supporting the monophyly of all 14 species of the subgenus Sebastomus among 54 congeners. The structural features and evolution of the 750 bp of the cytochrome b gene used to test the monophyly were similar to those of other vertebrates. Low levels of intrageneric sequence divergence (<10%) and incipient levels of saturation at third-codon positions were found in the gene. The monophyly of Sebastomus was supported in extensive phylogenetic analyses using distance, cladistic, and likelihood methods. Further corroboration was obtained from permutation- and simulation-based statistical tests.     

The Phylogeny of the Gasterosteidae: Combining Behavioral and Morphological Data Sets

Genealogical relationships among the five genera of stickleback (Gasterosteidae: Smegmomorpha) fishes were reconstructed based upon 47 behavioral and 89 morphological characters. Phylogenetic systematic analysis of the combined data set produced a single MPT (consistency index of 82.54%) structured ( Spinachia ( Apeltes-((Pungitius + Culaea )( Gasterosteus aculeatus + G. wheatlandi )))). When analyzed separately, both behavioral and morphological data sets produced the same tree topology, although the consistency index (excluding uninformative characters) was higher for the behavioral (90.70%) than for the morphological (68.13%) characters. This total evidence analysis provides a highly robust estimate of phylogeny for the sticklebacks and reiterates the importance of discarding a priori biases about behavioral evolution when selecting characters for phylogenetic analysis.     

Phylogeny and morphological evolution of the so‐called bougainvilliids (Hydrozoa,Hydroidolina)

We present phylogenetic analyses (parsimony, maximum likelihood and Bayesian inference) for 69 lineages of anthoathecate hydroids based on 18 morphological characters (12 proposed for the first time) plus mitochondrial (16S and COI) and nuclear (18S and 28S) molecular markers. This study aims to test the monophyly of the present concept of the family Bougainvilliidae, assessing its phylogenetic position within Hydroidolina. Our working hypothesis is used as a context for inferring the evolution of certain morphological characters, focusing on the exoskeleton. Our results shed light on some phylogenetic uncertainties within Hydroidolina, delimiting eight well‐supported linages, viz. Hydroidolina, Siphonophorae, Leptothecata, Aplanulata, Filifera II, Filifera III, Capitata and Pseudothecata taxon novum, the latter supported by four morphological synapomorphies. The monophyly of several families was not supported, viz. Bougainvilliidae, Cordylophoridae, Oceaniidae, Rathkeidae and Pandeidae. Some of the genera typically considered in Bougainvilliidae, including Bougainvillia, fell into the clade Pseudothecata, which is consistently reconstructed as the sister group of Leptothecata. We formally suggest that Dicoryne be removed from Bougainvilliidae and placed in the resurrected family Dicorynidae. The exoskeleton was a key feature in the diversification of Hydroidolina, especially with the transition from the bare hydranth to one completely enveloped within the exoskeleton. In this context, bougainvilliids exhibit several intermediate states in the development of the exosarc. Although the concatenated analysis unravels some interesting hypotheses, taxon sampling is still deficient and therefore more data are necessary for achieving a more complete understanding of the evolution and ecology of bougainvilliids and their allies.     

Integration of morphological data sets for phylogenetic analysis of Amniota: the importance of integumentary characters and increased taxonomic sampling

Several mutually exclusive hypotheses have been advanced to explain the phylogenetic position of turtles among amniotes. Traditional morphology-based analyses place turtles among extinct anapsids (reptiles with a solid skull roof), whereas more recent studies of both morphological and molecular data support an origin of turtles from within Diapsida (reptiles with a doubly fenestrated skull roof). Evaluation of these conflicting hypotheses has been hampered by nonoverlapping taxonomic samples and the exclusion of significant taxa from published analyses. Furthermore, although data from soft tissues and anatomical systems such as the integument may be particularly relevant to this problem, they are often excluded from large-scale analyses of morphological systematics. Here, conflicting hypotheses of turtle relationships are tested by (1) combining published data into a supermatrix of morphological characters to address issues of character conflict and missing data; (2) increasing taxonomic sampling by more than doubling the number of operational taxonomic units to test internal relationships within suprageneric ingroup taxa; and (3) increasing character sampling by approximately 25% by adding new data on the osteology and histology of the integument, an anatomical system that has been historically underrepresented in morphological systematics. The morphological data set assembled here represents the largest yet compiled for Amniota. Reevaluation of character data from prior studies of amniote phylogeny favors the hypothesis that turtles indeed have diapsid affinities. Addition of new ingroup taxa alone leads to a decrease in overall phylogenetic resolution, indicating that existing characters used for amniote phylogeny are insufficient to explain the evolution of more highly nested taxa. Incorporation of new data from the soft and osseous components of the integument, however, helps resolve relationships among both basal and highly nested amniote taxa. Analysis of a data set compiled from published sources and data original to this study supports monophyly of Amniota, Synapsida, Reptilia, Parareptilia, Eureptilia, Eosuchia, Diapsida, Neodiapsida, Sauria, Lepidosauria, and Archosauriformes, as well as several more highly nested divisions within the latter two clades. Turtles are here resolved as the sister taxon to a monophyletic Lepidosauria (squamates + Sphenodon), a novel phylogenetic position that nevertheless is consistent with recent molecular and morphological studies that have hypothesized diapsid affinities for this clade.     

A morphological supermatrix‐based phylogeny for the Neotropical fish superfamily Anostomoidea (Ostariophysi: Characiformes): phylogeny,missing data and homoplasy

Although 11 studies have addressed the systematics of the four families and 281 fish species of the ecomorphologically diverse Anostomoidea, none has proposed a global hypothesis of relationships. We synthesized these studies to yield a supermatrix with 463 morphological characters among 174 ingroup species, and inferred phylogeny with parsimony and Bayesian optimization. We evaluated the applicability of the supermatrix approach to morphological datasets, tested its sensitivity to missing data, determined the impact of homoplastic characters on phylogenetic resolution, and determined the distribution of homologies and homoplasies on the topology. Despite more than 60% missing data, analyses supported the monophyly of all families, and phylogenetic structure degraded only with inclusion of species with high percentages of missing data and in analyses limited to homoplasies. The latter differs modestly from the full matrix indicating phylogenetic signal in homoplastic characters. Character distributions differ across the phylogeny, with a greater prevalence of homologies at deeper nodes and homoplasies nearer the tips than expected by chance. This may suggest early diversification into distinct bauplans with subsequent diversification of faster evolving character systems. The morphological supermatrix approach is powerful and allows integration of classical data with modern methods to examine the evolution of multiple character systems.     

Molecular tests of phylogenetic taxonomies: a general procedure and example using four subfamilies of the lizard family Iguanidae

A general procedure is described for examining when results of molecular phylogenetic analyses warrant formal revision of taxonomies constructed using morphological characters. We illustrate this procedure with tests of monophyly for four subfamilies in the lizard family Iguanidae using 1561 aligned base positions (838 phylogenetically informative) of mitochondrial DNA sequences, representing coding regions for eight tRNAs, ND2, and portions of ND1 and COI. Ten new sequences ranging in length from 1732 to 1751 bases are compared with 12 previously reported sequences and 67 morphological characters (54 phylogenetically informative) from the literature. New morphological character states are provided for Sator. Phylogenies derived from the molecular and combined data are in agreement but both conflict with phylogenetic inferences from the morphological data alone. Strong support is found for the monophyly of the subfamilies Crotaphytinae and Phrynosomatinae. Monophyly of the Iguaninae is weakly supported in each analysis. All analyses suggest that the Tropidurinae is not monophyletic but the hypothesis of monophyly cannot be rejected. A phylogenetic taxonomy is proposed in which the Tropidurinae* is maintained as a metataxon (denoted with an asterisk), for which monophyly has not been demonstrated. Within the Phrynosomatinae, the close relationship of Sator and Sceloporus is questioned and an alternative hypothesis in which Sator is the sister taxon to a clade comprising Petrosaurus, Sceloporus, and Urosaurus is presented. Statistical tests of monophyly provide a powerful way to evaluate support for taxonomic groupings. Use of the metataxon prevents premature taxonomic rearrangements where support is lacking.     

Suprageneric relationships of galliform birds (Aves, Galliformes): a cladistic analysis of morphological characters

Of the basal clades of extant birds (Neornithes) the 'landfowl' or galliforms (Aves, Galliformes) are the most speciose. Cladistic analysis of more than 100 morphological characters coded at the generic level for most putative galliform genera confirms that the megapodes ('mound builders'; Megapodiidae) are the most basal clade within the order. They are followed successively by the curassows, guans and chachalacas (Cracidae), which comprise the sister-group to all other extant Galliformes (i.e. Phasianoidea). Within this large 'phasianoid' clade, analyses suggest that the guineafowl (Numididae) are the most basal taxon, although monophyly of this 'family' is not strictly supported on the basis of the morphological characters employed. An additional major clade within the phasianoid Galliformes is recovered by this analysis, comprising the traditional groupings of New World quails (Odontophoridae) and Old World quails ('Perdicini'), yet only monophyly of the former is supported unambiguously by morphological characters. Relationships within the remainder of the phasianoid taxa, including the grouse (Tetraonidae), turkeys (i.e. Meleagris / Agriocharus spp.) as well as other 'pavonine' galliforms (i.e. peafowl; Pavo , Afropavo , Rheinardia , Argusianus and Polyplectron spp.) remain largely unresolved on the basis of morphological characters, yet monophyly of the major subdivisions is supported here. Although there are a number of important differences, especially with regard to relationships within the nonquail phasianoids, the results of this morphological phylogenetic (cladistic) analysis are broadly congruent both with traditional classifications and existing molecular hypotheses of galliform phylogenetic relationships.     

Phylogenetic position of the Strepsiptera: Review of molecular and morphological evidence

Molecular evidence of the monophyly of the Halteria (Strepsiptera + Diptera) is reviewed. The majority of morphological characters, which have classically been used to establish a Strepsiptera + Coleoptera sister group, are rejected, because they are based on erroneous interpretations of strepsipteran morphology. The scorings of 31 morphological characters, which directly relate to the phylogenetic position of Strepsiptera, are provided, and their distribution and optimization on the molecular + morphological tree is discussed. Of these, 13 characters specifically support the placement of Strepsiptera within the Mecopterida; seven of which are based on the optimization of inapplicable or missing data, and six of which are based on states that can be scored for Strepsiptera. Only a single character (posteromotorism) suggests a sister group relationship with the Coleoptera. The morphological and molecular data are largely congruent, and suggest that the Strepsiptera are sister group to the Diptera.     

Increased taxon sampling provides new insights into the phylogeny and evolution of the subclass Calcaronea (Porifera,Calcarea)

Calcaronean sponges are acknowledged to be taxonomically difficult, and generally, molecular data does not support the current morphology-based classification. In addition, molecular markers that have been successfully employed in other sponge taxa (e.g., COI mtDNA) have proven challenging to amplify due to the characteristics of calcarean mitochondrial genomes. A short fragment of the 28S rRNA gene (C-region) was recently proposed as the most phylogenetically informative marker to be used as a DNA barcode for calcareous sponges. In this study, the C-region and a fragment of the 18S rRNA gene were sequenced for a wide range of calcareous taxa, mainly from the subclass Calcaronea. The resulting dataset includes the most comprehensive taxon sampling of Calcaronea to date, and the inclusion of multiple specimens per species allowed us to evaluate the performance of both markers, as barcoding markers. 18S proved to be highly conserved within Calcaronea and does not have sufficient signal to resolve phylogenetic relationships within the subclass. Although the C-region does not exhibit a “proper” barcoding gap, it provides good phylogenetic resolution for calcaronean sponges. The resulting phylogeny supports previous findings that the current classification of the subclass Calcaronea is highly artificial, and with high levels of homoplasy. Furthermore, the close relationship between the order Baerida and the genus Achramorpha suggest that the order Baerida should be abandoned. Although the C-region currently represents the best available marker for phylogenetic and barcoding studies in Calcaronea, it is necessary to develop additional molecular markers to improve the classification within this subclass.     

Molecular systematics of Eumolpinae and the relationships with Spilopyrinae (Coleoptera, Chrysomelidae)

The 3400 species of Eumolpinae constitute one of the largest subfamilies of leaf beetles (Chrysomelidae). Their systematics is still largely based on late 19th century monographs and remains highly unsatisfactory. Only recently, some plesiomorphic lineages have been split out as separate subfamilies, including the southern hemisphere Spilopyrinae and the ambiguously placed Synetinae. Here we provide insight into the internal systematics of the Eumolpinae based on molecular phylogenetic analyses of three ribosomal genes, including partial mitochondrial 16S and nuclear 28S and complete nuclear 18S rRNA gene sequences. Sixteen morphological characters considered important in the higher-level systematics of Eumolpinae were also included in a combined analysis with the molecular characters. All phylogenetic analyses were performed using parsimony by optimizing length variation directly on the tree, as implemented in the POY software. The data support the monophyly of the Spilopyrinae outside the clade including all sampled Eumolpinae, corroborating their treatment as a separate subfamily within the Chrysomelidae. The systematic placement of the Synetinae remains ambiguous but consistent with considering it a different subfamily as well, since the phylogenetic analyses using all the available evidence show the representative sequence of the subfamily also unrelated to the Eumolpinae. The Megascelini, traditionally considered a separate subfamily, falls within the Eumolpinae. Several recognized taxonomic groupings within Eumolpinae, including the tribes Adoxini or Typophorini, are not confirmed by molecular data; others like Eumolpini seem well supported. Among the morphological characters analyzed, the presence of a characteristic groove on the pygidium (a synapomorphy of the Eumolpini) and the shape of tarsal claws (simple, appendiculate or bifid) stand out as potentially useful characters for taxonomic classification in the Eumolpinae.