The seymouriamorph tetrapod Ariekanerpeton sigalovi from the Lower Permian of Tadzhikistan. Part II: Postcranial anatomy and relationships

2005 ◽  
Vol 96 (1) ◽  
pp. 71-93 ◽  
Author(s):  
Jozef Klembara ◽  
Marcello Ruta
Keyword(s):  
Posterior Margin ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Ventral Surface ◽  
Lower Permian ◽  
Postcranial Skeleton ◽  
Ventral Plate ◽  
Anterior Plate ◽  
Posterior Process ◽  
Postcranial Anatomy

ABSTRACTThe postcranial skeleton of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) differs from that of like-sized Discosauriscus specimens in showing: wider interclavicle anterior plate with smaller, rhomboidal sculptured field on its ventral surface not reaching plate posteromedial margins; broader interclavicle plate-stem junction; slightly narrower interclavicle posterior stem; anteroposteriorly narrower clavicle ventral plate with convex posterior margin; shorter, more robust humerus; four phalanges on fourth manus digit (five phalanges in Discosauriscus); ilium more elongate dorsoventrally with anteroposteriorly narrower neck; posterior process of iliac blade oriented distinctly posterodorsally rather than horizontally; more gracile atlantal rib; broadened distal end of second presacral rib. A revised cladistic analysis of the best known seymouriamorph species retrieves Ariekanerpeton either as sister group to both species of Discosauriscus, or to D. austriacus only.

The seymouriamorph tetrapod Utegenia shpinari from the ?Upper Carboniferous–Lower Permian of Kazakhstan. Part II: Postcranial anatomy and relationships

2003 ◽  
Vol 94 (1) ◽  
pp. 75-93 ◽  
Author(s):  
Jozef Klembara ◽  
Marcello Ruta
Keyword(s):  
Sister Taxon ◽  
Lower Permian ◽  
Postcranial Skeleton ◽  
Eastern Asia ◽  
Anterior Portion ◽  
Upper Carboniferous ◽  
Early Juvenile ◽  
Geographical Record ◽  
Anterior Trunk ◽  
Postcranial Anatomy

ABSTRACTThe postcranial skeleton of the seymouriamorph Utegenia shpinari (?Upper Carboniferous–Lower Permian, Kurgalin Formation, Kazakhstan) is redescribed. Features that distinguish it from other Lower Permian seymouriamorphs (Discosauriscus, Ariekanerpeton, Seymouria) are: broad anterior portion of the interclavicle stem, merging indistinctly into the interclavicle plate; absence of a bulge in the anterior half of such a stem; presence of at least 28 presacral vertebrae; gastralia. The poorly ossified limbs of the largest Utegenia specimens are similar in degree of development to those of larval Discosauriscus, but the almost cylindrical, anterior trunk pleurocentra recall the condition of early juvenile Discosauriscus. A phylogeny of the best known seymouriamorphs, using a small but diverse exemplar from other early tetrapod groups, places Utegenia within seymouriamorphs as sister taxon to discosauriscids (Ariekanerpeton plus Discosauriscus). This conclusion affects origin and dispersal scenarios for seymouriamorphs, and supports the hypothesis of a widespread geographical record of Lower Permian taxa spanning across western Euramerica and eastern Asia.

Description of the postcranial anatomy of Aulacephalodon baini and its possible relationship with 'Aulacephalodon peavoti'

2008 ◽  
Vol 104 (11/12) ◽  
Author(s):  
Romala Govender
Keyword(s):  
Femoral Head ◽  
Detailed Analysis ◽  
Convex Surface ◽  
Recent Analysis ◽  
Postcranial Skeleton ◽  
Greater Trochanter ◽  
Anterior Process ◽  
Posterior Process ◽  
Insight Into ◽  
Postcranial Anatomy

A recent analysis of the postcranial anatomy of Triassic dicynodonts renewed interest in the anatomy of Aulacephalodon. This study focused initially on Aulacephalodon baini as it represents medium to large Permian dicynodonts but also took into account 'Aulacephalodon peavoti'. The postcranial skeletons of A. baini and 'A. peavoti' show several significant differences. The scapula blade of A. baini is more curved than and not as upright as in 'A. peavoti'. A. baini has a rectangular delto-pectoral crest and has a better developed olecranon. In the pelvic girdle the anterior process is higher than the posterior process of the ilium in A. baini and the acetabulum is directed more ventrally. The femoral head is separated from the greater trochanter in A. baini. A comparison also shows that both A. baini and 'A. peavoti' are different from Rhachiocephalus in that the latter has a widely expanded scapula blade and the proximal end of the humerus is wider than the distal. The glenoid is elliptical with a convex surface. Although it could not be conclusively decided what the taxonomic position of 'A. peavoti' is, this study provides information about the postcranial skeleton which could aid its detailed analysis. This study will also assist in clarifying the relationships as well as providing insight into the palaeobiology of these extinct tetrapods.

The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution

1996 ◽  
Vol 87 (3) ◽  
pp. 363-421 ◽  
Author(s):  
M. I. Coates
Keyword(s):  
Phylogenetic Analysis ◽  
Vertebral Column ◽  
Femoral Shaft ◽  
Sister Group ◽  
Evolutionary Trends ◽  
Postcranial Skeleton ◽  
East Greenland ◽  
Caudal Direction ◽  
Postcranial Anatomy

ABSTRACTThe postcranial skeleton of Acanthostega gunnari from the Famennian of East Greenland displays a unique, transitional, mixture of features conventionally associated with fishand tetrapod-like morphologies. The rhachitomous vertebral column has a primitive, barely differentiated atlas-axis complex, encloses an unconstricted notochordal canal, and the weakly ossified neural arches have poorly developed zygapophyses. More derived axial skeletal features include caudal vertebral proliferation and, transiently, neural radials supporting unbranched and unsegmented lepidotrichia. Sacral and post-sacral ribs reiterate uncinate cervical and anterior thoracic rib morphologies: a simple distal flange supplies a broad surface for iliac attachment. The octodactylous forelimb and hindlimb each articulate with an unsutured, foraminate endoskeletal girdle. A broad-bladed femoral shaft with extreme anterior torsion and associated flattened epipodials indicates a paddle-like hindlimb function. Phylogenetic analysis places Acanthostega as the sister-group of Ichthyostega plus all more advanced tetrapods. Tulerpeton appears to be a basal stemamniote plesion, tying the amphibian-amniote split to the uppermost Devonian. Caerorhachis may represent a more derived stem-amniote plesion. Postcranial evolutionary trends spanning the taxa traditionally associated with the fish-tetrapod transition are discussed in detail. Comparison between axial skeletons of primitive tetrapods suggests that plesiomorphic fish-like morphologies were re-patterned in a cranio-caudal direction with the emergence of tetrapod vertebral regionalisation. The evolution of digited limbs lags behind the initial enlargement of endoskeletal girdles, whereas digit evolution precedes the elaboration of complex carpal and tarsal articulations. Pentadactylous limbs appear to have stabilised independently in amniote and amphibian lineages; the colosteid Greererpeton has a pentadactylous manus, indicating that basal amphibian forelimbs may not be restricted to patterns of four digits or less.

The postcranial skeleton, phylogenetic position, and probable lifestyle of the Early Triassic reptile Procolophon trigoniceps

2003 ◽  
Vol 40 (4) ◽  
pp. 527-556 ◽  
Author(s):  
Michael deBraga
Keyword(s):  
South Africa ◽  
Morphological Study ◽  
Lower Triassic ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Early Triassic ◽  
Postcranial Skeleton ◽  
Sister Clade ◽  
Key Innovations

A morphological study of the postcranial skeleton of Procolophon trigoniceps from the Lower Triassic of South Africa and Antarctica is undertaken. Procolophon shares a sister-group relationship with the procolophonid Tichvinskia from the Lower Triassic of Russia and is a basal member of Procolophonidae. This clade also includes the enigmatic taxon Sclerosaurus, believed most recently to be a pareiasaur relative. Owenettids form a separate lineage from Procolophonidae and are predominantly restricted to the Permian of both South Africa and Madagascar. A phylogenetically based assessment is considered, in which specialized modern taxa (sand lizards) are compared to their nonfossorial sister clade, allowing for "key innovations" to be identified. A similar comparison between owenettids and procolophonids reveals a number of apparent "key innovations" within procolophonids that are suggestive of a burrowing lifestyle for Procolophon.

Corrigendum to: Cladistic analysis and revision of Piestus Gravenhorst with remarks on related genera (Coleoptera : Staphylinidae : Piestinae)

2013 ◽  
Vol 27 (1) ◽  
pp. 129
Author(s):  
Edilson Caron ◽  
Cibele S. Ribeiro-Costa ◽  
Alfred F. Newton
Keyword(s):  
Cladistic Analysis ◽  
Taxonomic Revision ◽  
Sister Group ◽  
Morphological Characters ◽  
Valid Species ◽  
Phylogenetic Position ◽  
Neotropical Forests ◽  
Rove Beetles ◽  
New Synonyms ◽  
Branch Support

Rove beetles of the genus Piestus Gravenhorst, 1806 are commonly captured under the bark of or inside decaying logs from Neotropical forests. Piestus belongs to the subfamily Piestinae, historically an ill-defined dumping-ground for Staphylinidae defined by plesiomorphic characters, but which has gradually been restricted in concept and currently includes only six additional extant genera worldwide. Piestinae in this restricted sense has been considered a probably monophyletic subfamily, but its status and phylogenetic position, as a possible sister-group of Osoriinae within the recently proposed Oxyteline group of staphylinid subfamilies, are uncertain and need confirmation. The main aim of the present study was to provide a morphological cladistic analysis and complete taxonomic revision of Piestus, which, as the type and most speciose genus of Piestinae, is critical for future phylogenetic studies involving the subfamily. In our study, the monophyly of Piestus is established and phylogenetic relationships among its species are proposed based on 70 adult morphological characters. Piestus is supported by 11 synapomorphies and high branch support. All species of Piestus are revised and the genus is redefined. The genus contains 43 species, including 13 species described here for the first time. The previously proposed subgenera Antropiestus Bernhauer, 1917, Eccoptopiestus Scheerpeltz, 1952, Elytropiestus Scheerpeltz, 1952, Lissopiestus Scheerpeltz, 1952, Piestus s. str., Trachypiestus Scheerpeltz, 1952 and Zirophorus Dalman, 1821 have not been confirmed, as they were found to be poly- or paraphyletic, or are here removed from Piestus, and therefore subgenera are not used. The main taxonomic changes are as follows. Lissopiestus, syn. nov. is proposed as new synonym of Eleusis Laporte, 1835 and its species, E. interrupta (Erichson, 1840), comb. rest., is transferred again to that genus. Antropiestus, syn. nov. and Eccoptopiestus, syn. nov. are proposed as new synonyms of Hypotelus Erichson, 1839 and their species, H. laevis (Solsky, 1872), comb. nov. and H. andinus (Bernhauer, 1917), comb. nov., are transferred to Hypotelus. Fourteen new synonymies are proposed (valid species listed first): P. lacordairei Laporte, 1835 = Z. furcatus Sharp, 1887, syn. nov.; P. capricornis Laporte, 1835 = P. frontalis Sharp, 1876, syn. nov.; P. pennicornis Fauvel, 1864 = P. plagiatus Fauvel, 1864, syn. nov.; P. rectus Sharp, 1876, syn. nov.; P. pygialis Fauvel, 1902, syn. nov.; P. surinamensis Bernhauer, 1928, syn. nov.; P. minutus Erichson, 1840 = P. nigrator Fauvel, 1902, syn. nov.; P. sulcatus Gravenhorst, 1806 = P. sanctaecatharinae Bernhauer, 1906, syn. nov.; P. condei Wendeler, 1955, syn. nov.; P. gounellei Fauvel, 1902 = P. wasmanni Fauvel, 1902, syn. nov.; P. mexicanus Laporte, 1835 = P. alternans Sharp, 1887, syn. nov.; P. aper Sharp, 1876 = P. schadei Scheerpeltz, 1952, syn. nov.; P. angularis Fauvel, 1864 = P. crassicornis Sharp, 1887, syn. nov.; H. andinus (Bernhauer, 1917) = P. strigipennis Bernhauer, 1921, syn. nov. One species is revalidated: P. fronticornis (Dalman, 1821), stat. rev., and one synonym is restored: P. penicillatus (Dalman, 1821) = P. erythropus Erichson, 1840, syn. rest. Neotypes are designated for P. lacordairei Laporte, 1835 and Oxytelus bicornis Olivier, 1811, and lectotypes are designated for P. puncticollis Fauvel, 1902, P. capricornis variety muticus Fauvel, 1902, P. zischkai Scheerpeltz, 1951, P. pennicornis Fauvel, 1864, P. plagiatus Fauvel, 1864, P. pygmaeus Laporte, 1835, P. niger Fauvel 1864, P. minutus Erichson, 1840, P. nigratror Fauvel, 1902, P. sulcatus Gravenhorst, 1806, P. sanctaecatharinae Bernhauer, 1906, P. sulcipennis Scheerpeltz, 1952, P. aper Sharp, 1876, P. schadei Scheerpeltz, 1952 and P. andinus Bernhauer, 1917.

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.

A new arc-striped species of Corydoras Lacépède, 1803 (Teleostei: Callichthyidae) from the Peruvian Amazon

Zootaxa ◽  
2021 ◽  
Vol 4948 (2) ◽  
pp. 184-200
Author(s):  
REBECCA FRANCES BENTLEY ◽  
STEVEN GRANT ◽  
LUIZ FERNANDO CASERTA TENCATT
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Ventral Surface ◽  
River Basins ◽  
Color Pattern ◽  
The Body ◽  
Peruvian Amazon ◽  
Black Stripe ◽  
Dorsal Fin ◽  
Adaptive Value

A new Corydoras is described from the Blanco and Ucayali river basins in Peru. The new species can be distinguished from its congeners by having the following features: (I) posterior margin of dorsal-fin spine with laminar serrations directed towards the origin of the spine; (II) a long, wide, arched, and continuous black stripe, which runs parallel to the dorsal profile of the body, extending at least from the region below anterior origin of dorsal fin to the anterior half of the ventral caudal-fin lobe; (III) a black stripe transversally crossing the eye, forming the typical mask-like blotch; mask clearly not fused to arched stripe in most specimens; some specimens with mask separated from arched stripe by a thin line around the suture between neurocranium (in the region composed by the posteroventral margin of parieto-supraoccipital plus the posterodorsal margin of the compound pterotic) and first dorsolateral body plate; (IV) posterior margin of pectoral-fin spine with laminar serrations directed towards the origin of the spine; (V) pointed snout, presenting a long mesethmoid, with anterior tip larger than 50% of the entire length of the bone; and (V) ventral surface of trunk covered by small, non-coalescent platelets. A discussion on the possible positive adaptive value of the arc-striped color pattern is also provided. 

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.

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