DESCRIPTION OF THE LARVAE OF ELEVEN NEARCTIC SPECIES OF HYGROTUS STEPHENS (COLEOPTERA: DYTISCIDAE: HYDROPORINAE) WITH AN ANALYSIS OF THEIR PHYLETIC RELATIONSHIPS

1990 ◽  
Vol 122 (5) ◽  
pp. 985-1035 ◽  
Author(s):  
Y. Alarie ◽  
P.P. Harper ◽  
R.E. Roughley
Keyword(s):  
Abdominal Segment ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Structural Features ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
Systematic Analysis ◽  
Third Instar Larvae

AbstractA systematic analysis of larvae of 11 Nearctic species of Hygrotus Stephens was undertaken. The larvae are described and characterized; a key for their discrimination and illustrations of structural features of representatives of first- and third-instar larvae are provided. Many structural features, especially detailed variations in the chaetotaxy of cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for systematic and phylogenetic comparisons. Based on 21 larval characters, a cladistic analysis of the species studied was developed. A sister-group relationship between H. laccophilinus (LeConte) and the remaining available species is suggested. The less derived species, i.e. those without natatory setae on the legs, appear phylogenetically more closely related to the larvae of Hydroporus s.str. Hygrotus masculinus (Crotch) is the most derived species of the genus and, for many characters, seems more closely related to Hyphydrini. According to larval morphology, it is hypothesized that the genus Hygrotus diverged posteriorly to the genus Hydroporus Clairville.

Phylogenetic relationships, larval morphology, and chaetotaxy of the subfamily Coptotominae (Coleoptera: Dytiscidae)

2013 ◽  
Vol 145 (3) ◽  
pp. 247-264 ◽  
Author(s):  
Mariano C. Michat ◽  
Yves Alarie
Keyword(s):  
Phylogenetic Relationships ◽  
Abdominal Segment ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
First Instar ◽  
Segment Viii ◽  
Tracheal Gills

AbstractLarval morphology of the monogeneric subfamily Coptotominae (Coleoptera: Dytiscidae) is described and illustrated in detail, with particular emphasis on morphometry and chaetotaxy. Larvae ofCoptotomusSay are unique within Dytiscidae in the presence of tracheal gills on the abdominal segments I–VI, a short bifid horn or nasale in instar I, long spinulae on the urogomphus in instar I, and rows of natatory setae on both the internal and external margins of the urogomphus in instars II and III. A cladistic analysis based on 125 larval characters sampled among representatives of other dytiscid subfamilies supports a sister-group relationship between Coptotominae and Laccophilinae based on the shared absence of setae LA10 and LA12 on the second labial palpomere and of pore ABc on the abdominal segment VIII. The clade Coptotominae + Laccophilinae resolved as sister to Lancetinae, all three subfamilies sharing the presence of an unusually low number of lamellae clypeales in the first instar (a condition called four-peg-pattern), postulated to have evolved secondarily within Dytiscidae.

DESCRIPTION OF LARVAE OF 17 NEARCTIC SPECIES OF HYDROPORUS CLAIRVILLE (COLEOPTERA: DYTISCIDAE: HYDROPORINAE) WITH AN ANALYSIS OF THEIR PHYLOGENETIC RELATIONSHIPS

1991 ◽  
Vol 123 (3) ◽  
pp. 627-704 ◽  
Author(s):  
Y. Alarie
Keyword(s):  
North America ◽  
Phylogenetic Relationships ◽  
Abdominal Segment ◽  
Sister Group ◽  
Head Capsule ◽  
Structural Features ◽  
Species Group ◽  
The Third ◽  
Third Instar Larvae

AbstractThe larvae of 17 species of Hydroporus Clairville were described and characterized; a key for their discrimination and illustrations of structural features of first- and third-instar larvae are provided. Many structural features, especially those of chaetotaxy and porotaxy of head capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for taxonomic and phylogenetic comparisons. Based on 21 larval characters, the phylogenetic relationships among the five main lineages of Hydroporus (s. lat.) occurring in North America were studied. Structurally, the species of the subgenus Hydroporus (s. str.) and of the vilis species-group (H. planiusculus Fall) were found to be the most generalized taxa whereas the subgenera Neoporus Guignot and Heterosternuta Strand encompassed the species with the most derived condition. The subgenus Heterosternuta was closely related to the subgenus Neoporus and both subgenera were hypothesized to form a distinct monophyletic unit on the basis of five synapomorphies. The only representative of the oblitus species-group studied, H. paugus Fall, was related to Hydroporus (s. str.) and the vilis species-group by the shape of the siphon. This species was a very peculiar clement within Hydroporus (s. lat.) because it was the only known species of the genus without stemmaia in the first- and second-instar larvae, with stemmata greatly reduced in size in the third-instar larvae, and with a secondary dorsomedian seta on antennomere 2. The larval features of Hydroporus (s. lat.) were compared with those of Hygrotus Stephens. The comparison suggested that both genera form a monophyletic unit, that each of them is a distinct monophyletic unit, and that Hydroporus (s. lat.) is the sister-group of Hygrotus Stephens.

The phylogenetic position of Hydrovatus Motschulsky: evidence from larval morphology of H. caraibus Sharp (Coleoptera: Dytiscidae: Hydroporinae)

2006 ◽  
Vol 37 (4) ◽  
pp. 419-432 ◽  
Author(s):  
Mariano Michat
Keyword(s):  
Cladistic Analysis ◽  
Sister Group ◽  
Instar Larva ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
First Instar ◽  
Basal Half ◽  
Relationship Of ◽  
First Time

AbstractThe phylogenetic position of Hydrovatus Motschulsky was investigated based on a cladistic analysis of 18 hydroporine taxa and 69 characters from larval morphology. For this purpose, the three larval instars of H. caraibus Sharp were described and illustrated for the first time, emphasizing the morphometry and chaetotaxy. The resulting cladogram supported a sister-group relationship of the tribes Hydrovatini and Hyphydrini, based on three unambiguous synapomorphies: the absence of pore ANh, the proximal insertion of seta LA8, and the abdominal segment VI sclerotized ventrally. The strong development of seta AB5 and the absence of pore PAj are other two potential synapomorphies for this clade. The tribe Vatellini was resolved as more closely related to members of Hydroporini than to Hyphydrini. However, the support obtained for this relationship was weak, since no unambiguous synapomorphies were discovered. Larvae of H. caraibus are characteristic within Hydroporinae in the absence of an occipital suture, the presence of a galea (secondarily derived according to this study), and the absence of setae LA3 and UR8 and pores PAm and PAo. First instar larva is also unique in that the egg bursters are basally placed on the frontoclypeus and the claws bear ventral spinulae on basal half.

The phylogenetic position of the tuatara, Sphenodon (Sphenodontida, Amniota), as indicated by cladistic analysis of the ultrastructure of spermatozoa

1992 ◽  
Vol 335 (1274) ◽  
pp. 207-219 ◽  
Keyword(s):  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Usual Concept ◽  
Cladistic Analyses ◽  
Relationship Of

Sphenodon has traditionally been regarded as a little changed survivor of the Permo-Triassic thecodont or eosuchian ‘stem reptiles’ but has alternatively been placed in the Lepidosauria as the plesiomorphic or even apomorphic sister-taxon of the squamates. A cladistic analysis of 16 characters from spermatozoal ultrastructure of Sphenodon and other amniotes unequivocally confirms its exceedingly primitive status. The analysis suggests that monotremes are the sister-group of birds; squamates form the sister-group of a bird + monotreme clade while the three sister-groups successively below the bird + monotreme + squa- mate assemblage are the caiman, the tuatara and the outgroup (turtles). The monotreme + bird couplet, supports the concept of the Haemothermia, but can only be regarded heuristically. The usual concept of mammals as a synapsid-derived outgroup of all other extant amniotes is not substantiated spermatologically. All cladistic analyses made, and a separate consideration of apomorphies, indicate that Sphenodon is spermatologically the most primitive amniote, excepting the Chelonia. It is advanced (apomorphic) for the amniotes in only two of the 16 spermatozoal characters considered. A close, sister-group relationship of Sphenodon with squamates is not endorsed.

On a new species of Ericaella Bonaldo (Araneae, Miturgidae, Eutichurinae), with a cladistic analysis of the genus

Zootaxa ◽  
2005 ◽  
Vol 835 (1) ◽  
pp. 1
Author(s):  
ALEXANDRE B. BONALDO ◽  
ANTONIO D. BRESCOVIT ◽  
CRISTINA A. RHEIMS
Keyword(s):  
New Species ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Outgroup Species ◽  
Optimal Tree ◽  
Fourth Species ◽  
A New Species

A fourth species of Ericaella, E. florezi n. sp., is described based on males and a female from Cauca, Colombia. A cladistic analysis of all known species of Ericaella, plus two outgroup species (Radulphius camacan Bonaldo and Eutichurus luridus Simon) is presented. The single optimal tree obtained depicted a sister group relationship between Ericaella longipes Chickering plus E. florezi sp. n. and E. samiria Bonaldo plus E. kaxinawa Bonaldo.

New information on the eggshell of ratites (Aves) and its phylogenetic implications

2003 ◽  
Vol 81 (6) ◽  
pp. 962-970 ◽  
Author(s):  
Darla K Zelenitsky ◽  
Sean P Modesto
Keyword(s):  
Cladistic Analysis ◽  
Sister Group ◽  
The Other ◽  
Data Matrix ◽  
Sister Taxon ◽  
Sister Group Relationship ◽  
New Information ◽  
Phylogenetic Implications ◽  
Skeletal Analysis ◽  
Large Living

A reappraisal of the eggshell of ratites clarifies aspects of its microstructure and ultrastructure. The phylogenetic usefulness of the eggshell data, consisting of discrete characters, is assessed using eggshell characters alone and by adding the eggshell characters to a data matrix from the literature based on skeletal characters. The resultant tree from the eggshell data alone yields Apteryx as the most basal ratite, dinornithids as the sister taxon of a clade of large living ratites, with Casuarius and Dromaius in a sister-group relationship. The combined eggshell and skeletal analysis revealed most groupings within Ratitae that were based on previous cladistic analysis of the skeletal characters alone, but also supports two equally parsimonious topologies: one identifies Dinornithidae and Apteryx as a clade at the base of Ratitae, and the other identifies Apteryx as the sister taxon of a clade consisting of all the other ratites. It is determined that the characteristics used to define the improperly named "ratite morphotype" in the current eggshell parataxonomy are not synapomorphies of the eggshell of Ratitae. An expanded cladistic analysis of the eggshells of avian and non-avian theropods is required to determine the phylogenetic usefulness of the characteristics of the ratite morphotype.

Visceral anatomy of the Malaysian snake genus Xenophidion, including a cladistic analysis and allocation to a new family (Serpentes: Xenophidiidae)

1998 ◽  
Vol 19 (4) ◽  
pp. 385-405 ◽  
Author(s):  
Van Wallach ◽  
Rainer Günther
Keyword(s):  
Phylogenetic Analysis ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Neotropical Region ◽  
Sister Group Relationship ◽  
Internal Anatomy ◽  
New Family ◽  
Visceral Anatomy

AbstractThe internal anatomy of Xenophidion is described and compared with that of members of other snake families. A suite of primitive characters eliminates Xenophidion as a possible member of the Caenophidia; only two characters could conceivably suggest a relationship to the Caenophidia and both are examples of losses and thus of low phylogenetic value in assessing relationships. However, among lower snakes a sister group relationship is demonstrated with the Tropidophiidae of the Neotropical region. Besides possessing nearly identical viscera and topographical arrangement thereof, Xenophidion shares several characters with the Tropidophiidae. A new family is created to contain the genus, the Xenophidiidae. The Xenophidiidae share one synapomorphy with both the Tropidophiidae and Bolyeriidae. Therefore, it is proposed that these three families be united in the superfamily Tropidophioidea. A phylogenetic analysis of 52 characters results in the following preferred hypothesis of relationships: (Boinae, (((Bolyeria, Casarea), (Xenophidion, ((Exiliboa, Ungaliophis), (Trachyboa, Tropidophis)))), Acrochordus)).

Larvae and pupae of Dascillidae (Coleoptera): morphological study and discussion of their relationships to Scarabaeoidea and Eulichadidae

2003 ◽  
Vol 34 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Clarke Scholtz ◽  
Vasily Grebennikov
Keyword(s):  
North America ◽  
Morphological Variation ◽  
Morphological Study ◽  
Body Shape ◽  
Sister Group ◽  
Close Relative ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
The Family ◽  
Late Instar

AbstractExternal morphology of late-instar larvae and pupae of the coleopteran family Dascillidae is revised. Larvae studied for Dascillus Latreille with two species from Europe and North America, Notodascillus Carter from Australia and Pleolobus Philippi from Chile; pupae studied for D. davidsoni LeConte. Larval diagnosis and description of the family are updated. Dascillid larvae exhibit little morphological variation and share eight apparently apomorphic characters. Widely accepted sister-group relationship between Dascillidae and Rhipiceridae is not supported with larval morphology because ectoparasitic larvae of Rhipiceridae are poorly known and apparently highly modified morphologically. The superfamily Scarabaeoidea is unlikely to be a close relative of Dascillidae since this hypothesis is based mainly on habitat-dependent convergences of soil-dwellers (grub-like body shape, reduced stemmata) or possible symplesiomorphic similarities. Ten similarities between larvae of Dascillidae and Eulichadidae (Dryopoidea) were found. Some of these are possibly synapomorphies of these two groups. Larval and pupal morphology of Dascillidae is illustrated by 26 drawings.

Cuticular morphology of larval mountain midges (Diptera: Deuterophlebiidae): implications for the phylogenetic relationships of Nematocera

1990 ◽  
Vol 68 (3) ◽  
pp. 556-578 ◽  
Author(s):  
Gregory W. Courtney
Keyword(s):  
Phylogenetic Relationships ◽  
Feeding Behaviour ◽  
Morphological Characteristics ◽  
Sister Group ◽  
Head Capsule ◽  
External Morphology ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
Food Acquisition ◽  
Cuticular Structure

The cuticular structure of larval mountain midges (Diptera: Deuterophlebiidae) is described, with emphasis on cranial and mouthpart morphology. Homologies are suggested for musculature and external features of the head capsule. External morphology of the thorax and abdomen is described, and a system for deuterophlebiid larval chaetotaxy is presented. Also included is a discussion of the feeding behaviour of deuterophlebiid and blepharicerid larvae, and how differing morphological characteristics influence mechanisms of food acquisition. Larval morphology of the Deuterophlebiidae and other Nematocera provides support for (i) a sister-group relationship between the Deuterophlebiidae and Blephariceridae; (ii) a monophyletic Blephariceromorpha (sensu Wood and Borkent) composed of the Nymphomyiidae + (Deuterophlebiidae + Blephariceridae); and (iii) a sister-group relationship between the Blephariceromorpha and Psychodomorpha (sensu Wood and Borkent).

A phylogeny of Plesiosauria (Sauropterygia) and its bearing on the systematic status of Leptocleidus Andrews, 1922

Zootaxa ◽  
2008 ◽  
Vol 1863 (1) ◽  
pp. 1 ◽  
Author(s):  
PATRICK S. DRUCKENMILLER ◽  
ANTHONY P. RUSSELL
Keyword(s):  
Late Jurassic ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
New Taxon ◽  
Short Neck ◽  
Operational Taxonomic Units ◽  
Phylogenetic Hypotheses ◽  
The Uk

Leptocleidus Andrews, 1922 is a poorly known plesiosaur genus from Lower Cretaceous successions of the UK, South Africa, and Australia. Historically, there has been little consensus regarding its phylogenetic position within Plesiosauria, largely because of its seemingly aberrant combination of a relatively small skull and short neck. As a result, a diverse array of potential sister groups have been posited for Leptocleidus, including long-necked Cretaceous elasmosaurids, Early Jurassic “rhomaleosaurs”, and Middle to Late Jurassic pliosaurids. A cladistic analysis including Leptocleidus, and a new, apparently morphologically similar specimen from Alberta, TMP 94.122.01, was undertaken to assess their phylogenetic position within Plesiosauria. A character-taxon matrix was assembled afresh, consisting of 33 operational taxonomic units sampled broadly among plesiosaurs. 185 cranial and postcranial characters used in plesiosaur phylogenetics were critically reanalyzed, of which 152 were employed in the parsimony analysis. The results indicate a basal dichotomous split into the traditionally recognized pliosauroid and plesiosauroid clades. Nested within Pliosauroidea, a monophyletic Leptocleididae was recovered, consisting of L. superstes Andrews, 1922 and L. capensis (Andrews, 1911a). In contrast to earlier suggestions, Leptocleidus neither clusters with Rhomaleosaurus, which was found to be paraphyletic, nor with large-skulled pliosaurid taxa, such as Simolestes. Rather, a sister group relationship between Cretaceous Polycotylidae and Leptocleididae was recovered, which is here named Leptocleidoidea. Although TMP 94.122.01 is superficially similar to Leptocleidus, several discrete characters of the skull nest this new taxon within Polycotylidae. Compared to other phylogenetic hypotheses of plesiosaurs, these results are more congruent with respect to the stratigraphic distribution of leptocleidoids. A classification for Plesiosauria is presented.

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