Homology of the astragalus and structure and function of the tarsus of Diadectidae

2003 ◽  
Vol 77 (1) ◽  
pp. 172-188 ◽  
Author(s):  
David S Berman ◽  
Amy C. Henrici

Superbly preserved tarsi of a new, undescribed, primitive member of Diadectidae and of Diadectes, the best known member of the family, are described. The major distinction between them is the retention of sutures in the astragalus of the former which clearly indicate an origin from the fusion of three separate ossifications considered homologues of the primitive amphibian tibiale, intermedium, and proximal centrale. Among the Diadectomorpha (includes also Limnoscelidae and Tseajaiidae) only Diadectidae possesses an astragalus, which is considered a synapomorphy of the family within this grouping. Furthermore, the sister-group relationship of the new, undescribed diadectid to the other diadectids demonstrates a transformational, phylogenetic homology of the astragalus via the ontogenetic fusion of the primitive amphibian tarsal bones. The astragalus of diadectids is identical to those of late Paleozoic terrestrial amniotes in structure and relationship to neighboring elements. This, plus the wide acceptance of a close relationship between Diadectomorpha and Amniota, is cited as suggestive of an identical developmental origin of their astragali.In diadectids, including fully mature individuals, an unusual reduction or absence of ossification of some central and distal tarsal bones has resulted in an unique tarsus with large unoccupied areas and a structural pattern in which the only bony link between the tarsus and the digits is via the fourth distal tarsal, producing a crude facsimile of the lacertilian mesotarsal joint. Such a joint would have permitted, as in lacertilians, a wide range of movements which may have served several important functions: 1) maintaining an anteriorly directed pes to maximize the force of its posterior thrust during limb retraction, 2) placement of the pes close to the body midline for greater stride length and more efficient support and greater maneuverability during locomotion.

Zootaxa ◽  
2008 ◽  
Vol 1780 (1) ◽  
pp. 1 ◽  
Author(s):  
FLÁVIO A. BOCKMANN ◽  
AMALIA M. MIQUELARENA

Rhamdella cainguae, a new species of the family Heptapteridae is described from the Arroyo Cuña-Pirú, a tributary of the Río Paraná, in the subtropical forest of Misiones, northeastern Argentina. The presence of a large differentiated ovoid area on the supraorbital laterosensory canal along the frontal-sphenotic boundary, delimited by the slender dorsal walls of the bones, and with no foramen for a laterosensory branch, is an autapomorphy for R. cainguae. A detailed description of the skeleton and laterosensory system of R. cainguae is provided. The genus Rhamdella is rediagnosed on the basis of three autapomorphies: a very large opening in the frontal for the exit of the s6 (epiphyseal) branch of the supraorbital laterosensory canal (reversed in R. rusbyi), a large optic foramen, and a dark stripe along the lateral surface of the body (reversed in R. rusbyi). Rhamdella is considered to be the sister group of a large heptapterid clade composed of the Nemuroglanis sub-clade plus the genera Brachyglanis, Gladioglanis, Leptorhamdia, and Myoglanis. Rhamdella is herein restricted to five valid species: R. aymarae, R. cainguae, R. eriarcha, R. longiuscula, and R. rusbyi. A sister group relationship between R. aymarae and R. rusbyi is supported by three synapomorphies. Rhamdella cainguae shares 12 apomorphic features with R. eriarcha and R. longiuscula.


2003 ◽  
Vol 77 (4) ◽  
pp. 691-697 ◽  
Author(s):  
Alycia L. Rode ◽  
Bruce S. Lieberman ◽  
A. J. Rowell

Although bradoriids locally are common components of the Cambrian biota, they have been reported previously from Antarctica only from Tertiary glacial deposits. Here, we describe the bradoriid,Bicarinella evansinew genus and species, collected in situ from the upper Lower Cambrian (Botomian) of the Pensacola Mountains in East Antarctica.Bicarinella evansin. gen and sp. is characterized by a subtriangular carapace with a well-defined marginal rim, subequal anterior and posterior lobes that are elongated into sharp ridges extending one-third the length of the carapace, and a broad dorsal node placed between the anterior and posterior lobes. The surface of the carapace exhibits three kinds of ornamentation: fine pitting, pustules, and reticulae. Several smaller carapaces with reduced ornamentation collected from the same bed are interpreted as instars of this species.Bicarinellan. gen. is assigned to the family Hipponicharionidae and appears to be closely related toAlbrunnicolaMartinsson, 1979, orHipponicharionMatthew, 1886. Although strong archaeocyath faunal similarities demonstrate a close biogeographic relationship between Australia and Antarctica in the Early Cambrian, the possible sister group relationship ofBicarinellan. gen. toHipponicharion, which is otherwise unknown from Gondwana, may suggest a separate biogeographic pathway to East Antarctica that did not involve Australia.


Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1875
Author(s):  
Ran Li ◽  
Zhenxing Ma ◽  
Changfa Zhou

Mayflies of the family Neoephemeridae are widespread in the Holarctic and Oriental regions, and its phylogenetic position is still unstable in the group Furcatergalia (mayflies with fringed gills). In the present study, we determined the complete mitogenomes of two species, namely Potamanthellus edmundsi and Pulchephemera projecta, of this family. The lengths of two mitogenomes were 15,274 bp and 16,031 bp with an A + T content of 73.38% and 73.07%, respectively. Two neoephemerid mitogenomes had a similar gene size, base composition, and codon usage of protein-coding genes (PCGs), and the sequenced gene arrangements were consistent with the putative ancestral insect mitogenomes as understood today. The most variable gene of Furcatergalia mitogenomes was ND2, while the most conserved gene was COI. Meanwhile, the analysis of selection pressures showed that ND6 and ATP8 exhibited a relaxed purifying selection, and COI was under the strongest purifying selection. Phylogenetic trees reconstructed based on two concatenated nucleotide datasets using both maximum likelihood (ML) and Bayesian inference (BI) estimations yielded robust identical topologies. These results corroborated the monophyly of seven studied families and supported the family Leptophlebiidae as being of the basal lineage of Furcatergalia. Additionally, the sister-group relationship of Caenidae and Neoephemeridae was well supported. Methodologically, our present study provides a general reference for future phylogenetic studies of Ephemeroptera at the mitogenome level.


2021 ◽  
Vol 20 (7) ◽  
pp. 911-927
Author(s):  
Lucia Muggia ◽  
Yu Quan ◽  
Cécile Gueidan ◽  
Abdullah M. S. Al-Hatmi ◽  
Martin Grube ◽  
...  

AbstractLichen thalli provide a long-lived and stable habitat for colonization by a wide range of microorganisms. Increased interest in these lichen-associated microbial communities has revealed an impressive diversity of fungi, including several novel lineages which still await formal taxonomic recognition. Among these, members of the Eurotiomycetes and Dothideomycetes usually occur asymptomatically in the lichen thalli, even if they share ancestry with fungi that may be parasitic on their host. Mycelia of the isolates are characterized by melanized cell walls and the fungi display exclusively asexual propagation. Their taxonomic placement requires, therefore, the use of DNA sequence data. Here, we consider recently published sequence data from lichen-associated fungi and characterize and formally describe two new, individually monophyletic lineages at family, genus, and species levels. The Pleostigmataceae fam. nov. and Melanina gen. nov. both comprise rock-inhabiting fungi that associate with epilithic, crust-forming lichens in subalpine habitats. The phylogenetic placement and the monophyly of Pleostigmataceae lack statistical support, but the family was resolved as sister to the order Verrucariales. This family comprises the species Pleostigma alpinum sp. nov., P. frigidum sp. nov., P. jungermannicola, and P. lichenophilum sp. nov. The placement of the genus Melanina is supported as a lineage within the Chaetothyriales. To date, this genus comprises the single species M. gunde-cimermaniae sp. nov. and forms a sister group to a large lineage including Herpotrichiellaceae, Chaetothyriaceae, Cyphellophoraceae, and Trichomeriaceae. The new phylogenetic analysis of the subclass Chaetothyiomycetidae provides new insight into genus and family level delimitation and classification of this ecologically diverse group of fungi.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 779 ◽  
Author(s):  
Ke-Ke Xu ◽  
Qing-Ping Chen ◽  
Sam Pedro Galilee Ayivi ◽  
Jia-Yin Guan ◽  
Kenneth B. Storey ◽  
...  

Insects of the order Phasmatodea are mainly distributed in the tropics and subtropics and are best known for their remarkable camouflage as plants. In this study, we sequenced three complete mitochondrial genomes from three different families: Orestes guangxiensis, Peruphasma schultei, and Phryganistria guangxiensis. The lengths of the three mitochondrial genomes were 15,896 bp, 16,869 bp, and 17,005 bp, respectively, and the gene composition and structure of the three stick insects were identical to those of the most recent common ancestor of insects. The phylogenetic relationships among stick insects have been chaotic for a long time. In order to discuss the intra- and inter-ordinal relationship of Phasmatodea, we used the 13 protein-coding genes (PCGs) of 85 species for maximum likelihood (ML) and Bayesian inference (BI) analyses. Results showed that the internal topological structure of Phasmatodea had a few differences in both ML and BI trees and long-branch attraction (LBA) appeared between Embioptera and Zoraptera, which led to a non-monophyletic Phasmatodea. Consequently, after removal of the Embioptera and Zoraptera species, we re-performed ML and BI analyses with the remaining 81 species, which showed identical topology except for the position of Tectarchus ovobessus (Phasmatodea). We recovered the monophyly of Phasmatodea and the sister-group relationship between Phasmatodea and Mantophasmatodea. Our analyses also recovered the monophyly of Heteropterygidae and the paraphyly of Diapheromeridae, Phasmatidae, Lonchodidae, Lonchodinae, and Clitumninae. In this study, Peruphasma schultei (Pseudophasmatidae), Phraortes sp. YW-2014 (Lonchodidae), and species of Diapheromeridae clustered into the clade of Phasmatidae. Within Heteropterygidae, O. guangxiensis was the sister clade to O. mouhotii belonging to Dataminae, and the relationship of (Heteropteryginae + (Dataminae + Obriminae)) was recovered.


1992 ◽  
Vol 335 (1274) ◽  
pp. 207-219 ◽  

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.


Zootaxa ◽  
2021 ◽  
Vol 4992 (1) ◽  
pp. 1-89
Author(s):  
ADRIAN ARDILA-CAMACHO ◽  
CALEB CALIFRE MARTINS ◽  
ULRIKE ASPÖCK ◽  
ATILANO CONTRERAS-RAMOS

Adult external morphology of the extant raptorial Mantispoidea (Insecta: Neuroptera: Mantispidae and Rhachiberothidae) is compared emphasizing the morphology of the subfamily Symphrasinae as a key group to understand the phylogenetic relationships among the members of the superfamily. Plega dactylota Rehn, 1939 is thoroughly characterized in order to exemplify the morphology of the Symphrasinae. Additionally, following a review of the literature and examination of comparative material of Dilaridae, Berothidae, Rhachiberothidae and all Mantispidae subfamilies, a new interpretation of the components of the raptorial apparatus (i.e., head, prothorax, grasping forelegs, as well as integumentary specializations) is presented. Also, wing venation for these groups is reinterpreted, and new homology hypotheses for wing venation are proposed based on tracheation and comparative analyses. Given the high morphological divergence on the genital sclerites within the Mantispoidea, plus the confusing previous usage of neutral terminology and terms referring to appendages across taxonomic and morphological studies, we attempt to standardize, simplify, and situate terminology in an evolutionary context under the “gonocoxite concept” (multi-coxopod hypothesis). The remarkable morphological similarity of the genital sclerites of Symphrasinae and Rhachiberothidae (sensu U. Aspöck & Mansell 1994) with the Nallachinae (Dilaridae) was taken as a starting point to understand the morphology of other Mantispidae subfamilies. Based on these morphological comparisons, we provide a revised phylogenetic analysis of Mantispoidea. This new phylogenetic analysis supports a sister group relationship between the family Rhachiberothidae, comprising Rhachiberothinae and Symphrasinae, and the family Mantispidae, including the subfamily Mantispinae and its sister taxa Drepanicinae and Calomantispinae, which may represent a single subfamily. Based on these analyses, raptorial condition probably evolved a single time in these insects and subsequently became diversified in the two sister clades of the raptorial Mantispoidea.  


Zootaxa ◽  
2019 ◽  
Vol 4674 (3) ◽  
pp. 375-385
Author(s):  
EDUARDO DOMÍNGUEZ ◽  
MARÍA GABRIELA CUEZZO ◽  
SIMÓN CLAVIER

Four of the 43 genera of South American Leptophlebiidae are dipterous. A previous phylogenetic hypothesis supported that clade Askola+Hagenulopsis, and that Bessierus+Perissophlebiodes, are sister groups of the Farrodes complex. Adults of Bessierus and Perissophlebiodes were not known but posteriorly Perissophlebiodes male imago was described. Here, we describe the male imago of Bessierus for the first time. Both genera share, besides the absence of the hind wings, the asymmetrical fork of MA, symmetrical fork of MP, dissimilar tarsal claws, and forceps sockets fused. Along with the description of the imago, a new diagnosis for the genus Bessierus is presented, also updating the identification key with this new information. A new cladistics analysis is performed to test the stability of the proposed relationships of these four genera within Leptophlebiidae. We obtained a single cladistic hypothesis where the addition of Bessierus adult characters resulted in new synapomorphies for the (Bessierus, Perissophlebiodes) clade, and improved its clade statistical support. The fused forceps sockets resulted in a synapomorphy uniting Bessierus, Perissophlebiodes and Simothraulopsis. As a result of this new analysis, the hypothesis of independent losses of the hind wings in the two dipterous groups studied is supported. The Farrodes lineage is not supported as proposed in previous studies, being restricted only to (Farrodes (Simothraulopsis, Homothraulus)) while the identity of “Perissophlebiodes lineage” is supported. The sister group relationship of Rondophlebia is not clearly defined. 


2008 ◽  
Vol 276 (1655) ◽  
pp. 239-245 ◽  
Author(s):  
Moriya Ohkuma ◽  
Satoko Noda ◽  
Yuichi Hongoh ◽  
Christine A Nalepa ◽  
Tetsushi Inoue

Cryptocercus cockroaches and lower termites harbour obligate, diverse and unique symbiotic cellulolytic flagellates in their hindgut that are considered critical in the development of social behaviour in their hosts. However, there has been controversy concerning the origin of these symbiotic flagellates. Here, molecular sequences encoding small subunit rRNA and glyceraldehyde-3-phosphate dehydrogenase were identified in the symbiotic flagellates of the order Trichonymphida (phylum Parabasalia) in the gut of Cryptocercus punctulatus and compared phylogenetically to the corresponding species in termites. In each of the monophyletic lineages that represent family-level groups in Trichonymphida, the symbionts of Cryptocercus were robustly sister to those of termites. Together with the recent evidence for the sister-group relationship of the host insects, this first comprehensive study comparing symbiont molecular phylogeny strongly suggests that a set of symbiotic flagellates representative of extant diversity was already established in an ancestor common to Cryptocercus and termites, was vertically transmitted to their offspring, and subsequently became diversified to distinct levels, depending on both the host and the symbiont lineages.


1997 ◽  
Vol 10 (6) ◽  
pp. 855 ◽  
Author(s):  
Mats H. G. Gustafsson ◽  
Kåre Bremer

The genus Carpodetus from New Zealand, New Guinea, and the Solomon Islands, traditionally has been included in the extremely heterogeneous Saxifragaceae sensu lato, but on account of morphological peculiarities it has sometimes been classified in its own family. On palynological grounds it has been suggested to belong near the Ericales. Parsimony analyses of matrices comprising rbcL sequences of 80 taxa sampled from the entire Asteridae and Rosidae provide support for a sister group relationship between Carpodetus and a clade comprising the closely related Australian genera Abrophyllum and Cuttsia, also formerly placed in Saxifragaceae sensu lato, but recently shown to belong within the order Asterales sensu lato. A morphological comparison between the three interrelated genera is provided. They have in common an indumentum of thick-walled unicellular hairs with warty cuticle, and are also uniform in wood anatomy as well as fruit and seed structure. It is proposed that the family Carpodetaceae be expanded to encompass Abrophyllum and Cuttsia.


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