首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Gyrinidae is a group of beetles with a unique specialization of swimming on the water surface. Heterogyrus milloti Legros (Heterogyrinae) from Madagascar is a species with various preserved plesiomorphic features. The information on the morphology and biology was very limited until recently, and the thoracic anatomy remained largely unknown. Consequently, the aim of the present study is to describe external and internal thoracic features of Heterogyrus Legros in detail and to interprete them with respect to their phylogenetic and functional significance, with a special focus on the unusual flight apparatus of Gyrinidae. Characters documented with innovative techniques are compared to conditions found in other gyrinid genera and other groups of Adephaga, including characters of other body parts and larvae. A data matrix with 144 characters of adults, larvae and eggs was compiled and analysed cladistically. Gyrinidae excluding Spanglerogyrus Folkers (Heterogyrinae + Gyrininae) is supported by many apomorphies, mainly by a unique locomotor apparatus with paddle‐like middle and hind legs. The results confirm Heterogyrus as the earliest diverging branch in Gyrinidae except Spanglerogyrus, implying a sister‐group relationship between this genus and Gyrininae, a clade comprising Gyrinini, Dineutini and Orectochilini. The presence of an opening between the mesanepisternum and elytra, reduction of the lateral metafurcal arms, loss of the metathoracic M. furcacoxalis lateralis, and modifications of the head, including the dorsal shift of the upper subcomponent of the compound eyes, are synapomorphies of the three tribes. The monophyly of Gyrinini is moderately well‐supported, whereas Orectochilini is strongly supported by different characters including a highly simplified but functioning flight apparatus. A clade comprising Orectochilini and the dineutine genera is suggested by synapomorphies of adults and larvae. The monophyly of Dineutini was supported in a recent study, but not by the characters analysed here. Features of adults, larvae and eggs indicate that Gyrinidae are the sister group to the remaining adephagan families, as suggested in some earlier morphology‐based studies and recent analyses of large molecular datasets.  相似文献   

2.
Ariid monophyly and intrafamilial relationships are investigated based on cladistic analysis of 230 morphological characters. Terminal taxa examined include whenever possible type‐species, or the most morphologically similar species to the type‐species of the nominal genera, and the largest possible number of species, including cleared and stained specimens, available in zoological collections. Previous hypotheses about monophyly of the Ariidae are strongly corroborated by new synapomorphies discovered in the present study. The subfamily Galeichthyinae and the remaining ariids are strongly supported by new morphological characters. The monotypic subfamily Bagreinae is recognized as the sister group to all nongaleichthyin ariids, supported by a large series of exclusive synapomorphies. A new concept of Ariinae is presented: the subfamily is found to be unequivocally monophyletic and includes all ariid genera, except Galeichthys and Bagre. New data supporting the monophyly of the genera included in the Ariinae are introduced and previous hypotheses of monophyly, species composition, morphological definition, and relationships are reviewed and discussed.  相似文献   

3.
Spermatozoa ultrastructure was studied in five marines (Paralonchurus brasiliensis, Larimus breviceps, Cynoscion striatus, Micropogonias furnieri, Menticirrhus americanus, Umbrina coroides, Stellifer rastrifer), and one freshwater (Plagioscion squamosissimus) species of Sciaenidae and one species of Polynemidae (Polydactylus virginicus). The investigation revealed that, in all species, spermatozoa display a round head, a nucleus containing highly condensed, filamentous chromatin clusters, no acrosome, a short midpiece with a short cytoplasmic channel, and a flagellum showing the classic axoneme structure (9+2) and short irregular lateral fins. In Sciaenidae, the spermatozoa are type II, the flagellar axis is parallel to the nucleus, the lateral nuclear fossa is double arched, the centriolar complex is outside the nuclear fossa, the proximal centriole is anterior and perpendicular to the distal centriole, and no more than ten spherical (marine species) or elongate (freshwater species) mitochondria are observed. Polynemidae spermatozoa are of the intermediate type with the flagellar axis eccentric to the hemi-arc-shaped nucleus, and exhibit no nuclear fossa, the centriolar complex close to the upper nuclear end, the proximal centriole lateral and oblique to the distal centriole, and one large ring-shaped mitocondrion. The data available show that no characteristic is exclusively found in the spermatozoa of members of the Sciaenidae family when compared to other Percoidei with type II spermatozoa. However, three characteristics were exclusively found in Polynemidae: (1) the hemi-arched nucleus; the positioning of the centrioles; and (2) the ring-shaped mitocondrion. The interrelationships between Sciaenidae and Polynemidae as well as between these two families and other Percoidei are herein discussed.  相似文献   

4.
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.  相似文献   

5.
A phylogenetic hypothesis for the frogs of the genus Telmatobius that includes a comprehensive sample of the morphological and geographical variation is lacking. Obtaining such a hypothesis constitutes the main focus of this contribution. A phylogenetic matrix was generated based on 97 phenotypic characters and 56 terminals. A parsimony analysis of this matrix was performed with TNT. Telmatobius is found to be monophyletic and well supported by 11 synapomorphies. Although the consensus tree shows several polytomies, four main groups have been recovered. The well‐supported T. verrucosus Group includes forest and sub‐paramo species from Bolivia and Peru, and is the sister group of the remaining species. The T. bolivianus Group includes forest and inter‐Andean valley species from Argentina and Bolivia but it is poorly supported. Two supported high‐altitude groups have been recovered, the T. macrostomus Group from the Central Andes of Peru, and the T. marmoratus Group from the Altiplano‐Puna Plateau of Argentina, Bolivia, Peru and Chile and its adjacent Pacific and Northern slopes. The synapomorphies proposed for Telmatobius are discussed as well as the evolution of some of these synapomorphies and other characters within the genus.  相似文献   

6.
Yang Q  Zhu Y  Xiong B  Liu H 《Zoological science》2011,28(2):158-167
A new species of the bitterling genus Acheilognathus, Acheilognathus changtingensis sp. nov., was recently discovered from Changting County in Hanjiang River, Fujian Province, Southeastern China. It can be diagnosed by the following combination of characters: dorsal fin with three simple and 15 (occasionally 14) branched fin rays, anal fin with three simple and 12 (occasionally 11) branched fin rays; dorsal fin pale and anal fin slightly pale; white spots on anal-fin rays forming a transverse band, and anal fin margined with white band in males. Its unique characters are the many dispersed black spots on the dorsal, anal, pelvic, caudal fins, and on the head. Using the mitochondrial cytochrome Jb gene as a molecular marker, we reconstructed phylogenetic trees of A. changtingensis sp. nov. and other species in Acheilognathus to confirm its taxonomic status and study its speciation. Analyses of both morphological and molecular data consistently indicated the taxonomic status of the present new species. The results also show that A. changtingensis sp. nov. and Acheilognathus macropterus are sister species that diverged about 14.50 MYA by geographical isolation.  相似文献   

7.
The Copionodontinae is described as a new subfamily of the neotropical catfish family Trichomycteridae. It comprises two new genera and three new species from north-eastern Brazil: Copionodon gen. nov. (including C. pecten sp. nov. and C. orthiocarinatus sp. nov. ) and Glaphyropoma gen nov. (including G. rodriguesi sp. nov. ) The Copionodontinae can be diagnosed externally by the anterior position of the dorsal fin, the presence of a well-developed adipose fin, and the strongly spatulate shape of the jaw teeth. The subfamily is hypothesized as monophyletic on the basis of several synapomorphies in internal and external anatomy. Copionodontines have the plesiomorphic condition of several characters, relative to all other trichomycterids, including the presence of ductus pneumaticus; the possession of separate pterosphenoids, sphenotics and prootics; the presence of the intercalarium; the complete infraorbital latero-sensory canal; the presence of the interhyal; and the wide lateral opening of the swimbladder capsule. Elsewhere within trichomycterids, these primitive traits are found only in Trichogenes. These and other characters support the hypothesis that copionodontines are the plesiomorphic sister group of all other trichomycterids, and that Trichogenes is their next successive sister group. Contrary to the currently accepted hypothesis, the monotypic Nematogenyidae is proposed as the sister group of the Trichomycteridae, and not of all remaining loricarioids. This change is to a major extent induced by the inclusion of copionodontines and Trichogenes in the analysis of lower loricarioid relationships. The present case is given as an example of the impact that undiscovered taxa, fossil or Recent, may have upon hypotheses of phylogenetic relationships.  相似文献   

8.
Based on a cladistic analysis of 45 morphological (craniodental) and 46 binary allozyme characters, previous systematic treatments of the African murid tribe, Otomyini (laminate-toothed rats), are reviewed. Cladistic analysis of the craniodental data, involving eight outgroup taxa, confirmed the monophyly of the Otomyini, and suggested Pelomys to represent the sister genus of the Otomyini. Craniodental synapomorphies provided strong support for certain basal relationships among Otomyini rodents, reinforcing available palaeontological evidence. However, poor statistical (Bremer decay index) support was obtained for terminal relationships. The data presented revealed a 'mesic clade' of southern and eastern African species, with Otomys sloggetti basal to this group. The arid-adapted, southern Africa-endemic species, Parotomys littledalei , P. brantsii and O. unisulcatus , were all placed basal to the 'mesic clade', but did not form a separate 'arid clade', as suggested by earlier biochemical studies. Two allozyme synapomorphies supported the existence of the 'mesic clade', separate from arid-adapted southern African species. A strict cladistic interpretation of the present data did not support the existence of two genera in the tribe, and the two species of Parotomys (whistling rats) should be transferred to Otomys . At the species level, specific identity of O. lacustris and O. barbouri , distinct from O. anchietae , was supported by several autapomorphies, and O. tropicalis burtoni was shown to be included in O. angoniensis rather than O. tropicalis , extending the range of the former species into West Africa.  相似文献   

9.
The phylogenetic relationships among two Paracyprichromis and five Cyprichromis species, included in the Tanganyikan cichlid tribe Cyprichromini, were investigated using morphological features. The previously proposed diagnostic characters of Paracyprichromis are not synapomorphies, because the nonelongated swim bladder is plesiomorphic, the numbers of dorsal and anal fin rays and scales on longitudinal line and around the caudal peduncle overlap with those of Cyprichromis, and these counts and number of vertebrae are all included within the ranges of other Tanganyikan cichlids. The monophyly of Paracyprichromis is supported by a unique condition of infraorbitals to this genus. Additionally, the monophyly of Cyprichromis was reconfirmed by one of the previously proposed diagnostic characters, the presence of an elongated swim bladder.  相似文献   

10.
Molecular analysis of mitochondrial cytochrome b sequences from 159 species of the family Cyprinidae supports the subfamily Danioninae, of which Rasborinae is shown to be a junior synonym. Analysis of combined cytochrome b and a fragment of the nuclear rhodopsin gene from 68 species, including 43 species representing the subfamily Danioninae, supports phylogenetic distinctness of Danio and Devario. In the combined molecular analysis Microrasbora rubescens, Chela, Laubuca, Devario, and Inlecypris form a clade with M. gatesi , M. nana and M. kubotai being in sister group position to the rest. The sister group of this Devario clade is Danio . Inlecypris is synonymized with Devario. Microdevario, new genus, is proposed for M. gatesi , M. nana and M. kubotai , supported by morphological characters. In the cytochrome b analysis, M. rubescens falls outside Devario , and there is no morphological support for including M. rubescens in Devario . In the cytochrome b analysis Esomus  +  Danionella is the sister group of Danio and Devario clades, whereas in individual rhodopsin and combined analyses Esomus is the sister group of Danio , and of Danio and the Devario clade, respectively. Sundadanio presents at least one strong morphological synapomorphy with Danio , but is positioned in molecular trees either as a member of the Cyprininae or as sister group of the remaining Danioninae. In the morphological analysis, small-sized species grouped together based on shared reductions that are not necessarily synapomorphies. In the molecular analysis, small-sized species such as Danionella and Sundadanio possess long branches and their position varies, but they did not group together. This suggests morphological homoplasy, but phylogenetic positions are not well supported in the molecular analyses  相似文献   

11.
槭树科植物广义形态学性状分支分析   总被引:4,自引:0,他引:4  
通过45个广义的形态学性状对槭树科(Aceraceae)尤其是槭属(Acer L.)的主要类群做了分支分析,结果显示:1)槭属内由于各类群分布着较多的同塑性状状态,而难以为属下组间关系的解决提供更多有价值的信息;通过对具体的性状状态分布分析显示,对于象槭属这样在形态上分化较大的类群,由于多数分类性状在不同类群间经历了平行和逆转演化,因而在较低分类阶元水平很难选择合适的性状来通过分支分析构建其系统发育;2)鸡爪槭组(section Palmata)作为整个槭属的基部类群,虽然支持率较低,但与其它类群相比在槭属内维持了较多的原始性状;3)金钱槭属(Dipteronia Oliv.)的两个种作为单系得到了100%的靴带支持,且和槭属作为姐妹群也得到了较好的支持。  相似文献   

12.
Phylogenetic analysis of the Malacostraca (Crustacea)   总被引:13,自引:0,他引:13  
The Malacostraca comprises about 28 000 species with a broad disparity in morphology, anatomy, embryology, behaviour and ecology. The phylogenetic relationships of the major taxa are still under debate. Is the Leptostraca the sister group of the remaining Malacostraca, or is this taxon more closely related to other Crustacea? Does the Stomatopoda or the Bathynellacea represent the most basal taxon within the remaining taxa? Is the Peracarida monophyletic or are some peracarid taxa more closely related to other ‘caridoid’ taxa? Is the Thermosbaenacea part of the Peracarida or its sister group, and how much support is there for a taxon Amphipoda + Isopoda? To answer these questions a phylogenetic analysis of the Malacostraca combining different phylogenetic approaches was undertaken. In a first step, the monophyly of the Malacostraca including the Leptostraca is shown using the ‘Hennigian approach’. A computer cladistic analysis of the Malacostraca was carried out with NONA and PEE ‐WEE , based on 93 characters from morphology, anatomy and embryology. Nineteen higher malacostracan taxa are included in our analysis. Taxa whose representatives are exclusively fossils were not included. The Leptostraca was used as an operational out‐group. The present analysis supports the basal position of the Stomatopoda. Syncarida and Peracarida (including Thermosbaenacea) are supported as monophyletic, the Eucarida is not. Instead a sister‐group relationship is suggested between Euphausiacea and Peracarida (including Thermosbaenacea), with the Syncarida as the sister group to both taxa. Certain embryonic characters are interpreted as support for the monophyly of the Peracarida (without Thermosbaenacea) because convergences or reversals of these characters seem implausible. Within the Peracarida, the Mysidacea (Lophogastrida + Mysida) represents the sister group to the remaining taxa. A sister‐group relationship between Amphipoda and Isopoda is not supported.  相似文献   

13.
The recessus lateralis , a complex structure in the otic region of the skull that is probably associated with detection and analysis of small vibrational pressures and displacements, is widely recognized as a synapomorphy of the Clupeiformes. The Clupeiformes includes the Denticipitoidei, with one living species, Denticeps clupeoides , and the Clupeoidei, with about 360 living species commonly known as herrings and anchovies. Comparisons between details of the recessus lateralis of the Clupeoidei and Denticipitoidei, and the sensory cephalic canals of other teleosts, lead to hypotheses of a series of transformations of the cephalic sensory canals . Treating that complex as a single binary 'presence vs. absence' character as was traditional practice obscures important phylogenetically informative variation. Specific synapomorphies in that system exist for the Clupeiformes and the Clupeoidei. Hypothesized synapomorphies in the recessus lateralis for the Clupeiformes are the presence of a dilated internal temporal sensory canal in the pterotic, a postorbital branch of the supraorbital sensory canal located in a bony groove in the lateral wing of the frontal, and the terminal portions of preopercular and infraorbital sensory canals closely positioned. Hypothesized synapomorphies for the Clupeoidei are the presence of a postorbital branch of the supraorbital sensory canal located deep within the body of the lateral wing of the frontal, with the distal portion of that branch totally internal on the cranium, and the expanded distal portion of the postorbital branch of the supraorbital sensory canal. The homology of the sinus temporalis of Clupeoidei, and of the dermosphenotic of both Denticeps and the Clupeoidei, with those of other teleosts is also considered.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 141 , 257–270.  相似文献   

14.
Phylogeny of the flyingfish family Exocoetidae (Teleostei, Beloniformes)   总被引:2,自引:0,他引:2  
The phylogeny of the flyingfish family Exocoetidae is studied cladistically, using 41 morphological characters encompassing early life history, and external and internal features. The monophyly of the family is supported by 10 synapomorphies. Within the family,Oxyporhamphus is the sister group to all other genera, the monophyly of the latter being defined by 10 synapomorphies.Fodiator is the sister group of genera characterized by the presence of chin barbels in juveniles.Parexocoetus is the sister group ofExocoetus, Cypselurus, Prognichthys andHirundichthys, the latter being defined by four synapomorphies. In the latter group,Exocoetus is the sister group of the other three genera. The phylogeny of the Exocoetidae is characterized by the stepwise upgrading of gliding capability, with sequential modifications of the caudal, pectoral and pelvic fins. The subfamily Oxyporhamphinae is resurrected.  相似文献   

15.
A cladistic investigation of the phylogenetic relationships among the three extant anteater genera and the three undoubted extinct myrmecophagid genera is performed based upon osteological characteristics of the skull and postcranial skeleton. One hundred seven discrete morphological characters are analyzed using the computer program PAUP. Characters are polarized via comparison to the successive xenarthran outgroups Tardigrada (represented by the living sloth Bradypus) and Cingulata (represented by the recent armadillos Dasypus and Euphractus). The analysis results in a single most-parsimonious tree (TL = 190, CI = 0.699, RI = 0.713). The tree corroborates the monophyly of the subfamilies Cyclopinae and Myrmecophaginae, the former including the extant Cyclopes and the Pliocene genus Palaeomyrmidon. Within the Myrmecophaginae the Miocene genus Protamandua is the sister taxon to a clade including the remaining three genera. The recent Tamandua is in turn the sister taxon to the extant Myrmecophaga plus the Pliocene genus Neotamandua. Contrary to the suggestions of recent authors, weak support is provided for the taxonomic distinctiveness of the latter genus from the recent Myrmecophaga. The monophyly of the Myrmecophagidae is supported by 15 unequivocal synapomorphies. The monophyly of the Cyclopinae and Myrmecophaginae is supported by 3 and 13 unambiguous synapomorphies, respectively. The enigmatic Eocene genus Eurotamandua, from the Messel fauna of Germany, is coded for the 107 morphological characters above and included in two subsequent PAUP analyses. The palaeanodont Metacheiromys is also added to these two analyses as a nonxenarthran outgroup to test for the possibility that Eurotamandua lies outside the Xenarthra. In the first analysis, Eurotamandua is constrained a priori to membership in the Vermilingua. The single most-parsimonious tree (TL = 224, CI = 0.618) that results places Eurotamandua as the sister group to the remaining anteater genera, contra Storch and Habersetzer's (1991) assignment of Eurotamandua to the vermilinguan subfamily Myrmecophaginae. Eurotamandua shares six unequivocal synapomorphies with other anteaters, including the absence of teeth and the presence of a lateral tuberosity on the fifth metatarsal. The remaining vermilinguans are united by 11 unequivocal synapomorphies, plus an additional 10 ambiguous synapomorphies. In the second analysis, the position of Eurotamandua is unconstrained. The resulting single most-parsimonious tree (TL = 219, CI = 0.632) places Eurotamandua outside Vermilingua as the sister group to the Pilosa (Vermilingua plus Bradypus). The monophyly of this node is supported by four unambiguous synapomorphies in the unconstrained analysis. Further manipulation of this second analysis shows that placement of Eurotamandua as the sister group to the Xenarthra or to the Palaeanodonta adds three steps to the shortest tree but is more parsimonious than its placement as a sister group to the Vermilingua is the previous analysis. The addition of pangolins to the analysis does little to alter the major phylogenetic conclusions of the study. The allocation of Eurotamandua to the Xenarthra, but as a sister group to the Pilosa, is a novel arrangement which leaves open the biogeographic question of how a xenarthran reached Western Europe during the Eocene.  相似文献   

16.
A new arthrodire genus and species,Wildungenichthys grossi, is described from the Frasnian Kellwasserkalk of Bad Wildungen (W-Germany) from an incomplete skull with parts of the mandible and shoulder girdle. The new taxon is unique in a number of features, including the loss or probable fusion of the postmarginal, strong reduction of infraorbital sensory line canal on suborbital, firm connection of the cheek and skull roof and an unusual configuration of the cheek bones. It is an advanced pachyosteomorph eubrachythoracan and is referred to the Selenosteidae, showing close resemblances toEnseosteus.  相似文献   

17.
Snubnose darters comprise one of the largest subgenera of the percid genus Etheostoma. Many species are described based on differences in male breeding coloration. Few morphological synapomorphies have been proposed for the subgenus and their relatives, making it difficult to delineate monophyletic clades. The phylogenetic relationships of the 20 snubnose darter species of the subgenus Ulocentra and 11 members of its proposed sister subgenus Etheostoma were investigated with partial mitochondrial DNA sequences including 1033 bp encompassing the entire mitochondrial control region, the tRNA-Phe gene, and part of the 12S rRNA gene. Two hypotheses on the relationship and monophyly of the two subgenera were evaluated. Both maximum-parsimony and neighbor-joining analyses supported monophyly of the subgenus Ulocentra and resolved some species-level relationships. The banded darter, E. zonale, and its sister taxon, E. lynceum, were not closely related to the snubnose darters and appear to be diverged from the other members of the subgenus Etheostoma, fitting their former distinction as the recognized subgenus Nanostoma. The sister group to Ulocentra appears to be a restricted species assemblage within the subgenus Etheostoma containing E. blennioides, E. rupestre, E. blennius, and the E. thalassinum species group. The placement of the harlequin darter, E. histrio, is problematic, and it may represent a basal member of Ulocentra or of the restricted subgenus Etheostoma. Despite recent estimates of divergence times between nominal Ulocentra taxa, each species exhibits its own unique set of mtDNA haplotypes, providing no direct evidence for current genetic exchange between species. The nominal taxa of snubnose darters thus appear to be evolving independently from each other and therefore constitute valid species under the Phylogenetic Species Concept.  相似文献   

18.
Abstract We develop a morphological dataset for the rove beetle subfamily Euaesthetinae comprising 167 morphological characters (135 adult and 32 larval) scored from 30 terminal taxa including 25 ingroup terminals (from subfamilies Euaesthetinae and Steninae) and five outgroups. Four maximum parsimony analyses using different sets of terminals and character sets were run to test the monophyly of (1) Euaesthetinae, (2) Steninae, (3) Euaesthetinae + Steninae, (4) euaesthetine tribes Austroesthetini, Alzadaesthetini, Euaesthetini, Fenderiini and Stenaesthetini, and (5) the ten currently known austral endemic genera together. Analyses of adult and larval character sets separately and in combination recovered the monophyly of Euaesthetinae, Steninae, and both subfamilies together, with strong support. Analysis of 13 ingroup terminals for which complete data were available suggests that monophyly of Euaesthetinae is supported by 19 synapomorphies (13 adult, six larval), of Steninae by 23 synapomorphies (14 adult, nine larval), and of both subfamilies together by 24 synapomorphies (21 adult, three larval). Within Euaesthetinae, only the tribe Stenaesthetini was recovered as monophyletic based on adult characters, and in no analyses were the ten austral endemic genera recovered as a monophyletic group. Phylogenetic relationships among euaesthetine genera were weakly supported, although analyses including adult characters supported monophyly of Octavius and Protopristus separately, and of Octavius + Protopristus, Austroesthetus + Chilioesthetus and Edaphus + Euaesthetus. Steninae may include a third genus comprising two undescribed species probably possessing a ‘stick–capture’ method of prey capture, similar to that in Stenus. These two species formed a strongly supported clade recovered as the sister group of Stenus based on adult characters. Diagnoses and a key to adults are provided for the 15 euaesthetine genera currently known from the austral region (Australia, New Zealand, South Africa and southern South America). Euaesthetine larvae previously were known only for Euaesthetus, and we describe the larvae of nine more genera and provide the first larval identification key for genera of Euaesthetinae.  相似文献   

19.
The anatomy of species belonging to the superfamily Myliobatoidea was examined with the aim of better determining their phylogenetic relationships. A wide variation among genera was observed in skeletal anatomy, despite the fact that they all share a common morphological pattern. However, variation among species of the same genus was low, excepting Mobula. Dorsal musculature showed a substantial consistency, except for the epiaxialis muscle, which was larger in rhinopterids and mobulids. Variation in the ventral muscles was low among species of the same genus, but considerable among different genera. Mobulids have a reduction in ventral muscles, while rhinopterids and myliobatoids show an increase in muscular mass. A consensus tree shows a basal split into two groups. The first includes the family Gymnuridae with the genera Gymnura and Aetoplatea; this group is supported by seven synapomorphies, including: 27(1) ceratobranchialis fused proximally, 36(1) anterior lateral processes present in the synarcual, 52(0) quadratomandibularis internal muscle present. The second group is composed of the family Myliobatidae (Myliobatis, Aetomylaeus, Aetobatus, Rhinoptera, Mobula, and Manta), this group is supported by 11 synapomorphies, including: 5(1) first postorbital process fused with the second, 21(1) fused mandibular symphysis, 24(1) first hypobranchial cartilage absent, 48(2) epiaxialis muscle inserted in the cranial orbital region, 73(1) pectoral fins joined behind the orbital region. This study concluded that myliobatoids (Myliobatis, Aetomylaeus, and Aetobatus) integrate a monophyletic group which, unlike other phylogenies previously obtained, is the sister group of rhinopterids (Rhinoptera). Mobulids (Mobula and Manta) are the sister group of myliobatoids-rhinopterids.  相似文献   

20.
The phylogenetic relationships of the family Trichodontidae and suborder Cottoidei (and zoarcoid Bathymasteridae) are reconstructed morphologically. The monophyly of the Trichodontidae, Cottoidei, and Zoarcoidei is unambiguously supported by 14 synapomorphies, including 1 newly recognized (and also 4 synapomorphies when ACCTRAN is accepted). It is assumed that the Trichodontidae is deeply nested within the Cottoidei, and the family and Cottoidea plus Cyclopteroidea have a sister relationship, supporting a previously inferred molecular phylogenetic hypothesis. We propose that the Trichodontidae is placed into the cottoid superfamily Trichodontoidea.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号