A new dicynodont therapsid from the lowermost Beaufort Group, Upper Permian of South Africa

2002 ◽  
Vol 39 (12) ◽  
pp. 1755-1765 ◽  
Author(s):  
Sean P Modesto ◽  
Bruce S Rubidge ◽  
Johann Welman
Keyword(s):  
South Africa ◽  
Cladistic Analysis ◽  
Dorsal Surface ◽  
Lateral Wall ◽  
Sister Group ◽  
Data Matrix ◽  
Upper Permian ◽  
Sister Group Relationship ◽  
Eastern Cape ◽  
Close Relationship

Two fragmentary skulls from the Upper Permian Tapinocephalus Assemblage Zone (Abrahamskraal Formation, Beaufort Group) in Eastern Cape Province, South Africa, represent a new dicynodont taxon. Lanthanocephalus mohoii gen. et sp. nov. is distinguished from other dicynodonts by the presence of a conspicuous laterally facing excavation on the dorsal surface of the postfrontal, by dorsal expansions of the supraoccipital that contact the parietals, and by extensive ossification of the lateral wall of the braincase. Lanthanocephalus features several characters that are suggestive of a close relationship with Endothiodon. These include a transversely narrow intertemporal region, the presence of a pineal boss, and the presence of a distinct boss on the ventral margin of the jugal. Cladistic analysis of a modified data matrix from the literature supports the hypothesis of a sister-group relationship between Lanthanocephalus and Endothiodon. However, this grouping and most others found in the analysis collapse with one extra step, weaknesses that underscore the need for further research on dicynodonts and other non-mammalian synapsids.

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.

Redescription, phylogenetic position, and stratigraphic significance of the dicynodont genus Odontocyclops (Synapsida: Anomodontia)

2002 ◽  
Vol 76 (6) ◽  
pp. 1047-1059 ◽  
Author(s):  
Kenneth D. Angielczyk
Keyword(s):  
South Africa ◽  
South African ◽  
Cladistic Analysis ◽  
Dorsal Surface ◽  
Phylogenetic Position ◽  
Close Relative ◽  
Data Set ◽  
Karoo Basin ◽  
Close Relationship ◽  
Dorsal Process

The dicynodont anomodont Odontocyclops whaitsi, from the Late Permian Madumabisa Mudstone of Zambia, is redescribed and its phylogenetic relationships are considered. The genus is characterized by a two autapomorphies, elongate nasal bosses and a concave dorsal surface of the snout; it also possesses wide exposure of the parietals on the intertemporal skull roof, the presence of a postcaniniform crest, the absence of a labial fossa, and the presence of a dorsal process on the anterior ramus of the epipterygoid footplate. In addition, newly recognized specimens collected in South Africa extend the known geographic range of the genus and allow description of the humerus and scapula for the first time. Cladistic analysis of a data set including Odontocyclops and 18 other well-known South African dicynodont genera does not support the hypothesis that Odontocyclops is a close relative of Dicynodon or of Triassic dicynodonts such as Kannemeyeria. Instead, a close relationship with Oudenodon and Rhachiocephalus is proposed. The presence of Odontocyclops in South Africa and Zambia makes it potentially valuable for more precise biostratigraphic correlation between the sediments of the Karoo Basin and the Luangwa Valley.

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.

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.

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.

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)).

The phylogeny of the Hydroporinae and classification of the genus Peschetius Guignot, 1942 (Coleoptera: Dytiscidae)

2006 ◽  
Vol 37 (3) ◽  
pp. 257-279 ◽  
Author(s):  
William Wolfe ◽  
Kelly Miller ◽  
Olof Biström
Keyword(s):  
Cladistic Analysis ◽  
Sister Group ◽  
Morphological Characters ◽  
Close Relationship ◽  
Relationship Of ◽  
The Relationship

AbstractThe phylogeny of the Hydroporinae is investigated in a cladistic analysis emphasizing placement of the genus Peschetius Guignot, historically placed in the tribe Hydroporini. Sixty-nine adult and larval morphological characters were coded for 61 species of Hydroporinae representing eight of the nine tribes. Cladistic analysis of the data resulted in 396 most parsimonious cladograms (length = 176, CI = 46, RI = 80). The results indicate that the genus Peschetius is the sister group to the tribe Bidessini based mainly on an unambiguous character, the presence of a prominent internal spermathecal spine, and several other more ambiguous or homoplasious characters. The tribe Bidessini is expanded to include the genus Peschetius, and it is formally transferred from the tribe Hydroporini. Other results indicating interesting relationships of tribes and genera within Hydroporinae are also discussed. Results include; 1) a dramatically paraphyletic Hydroporini with Laccornellus Roughley and Wolfe, Canthyporus Zimmermann and Hydrocolus Roughley and Larson in basal positions within the phylogeny, 2) Hydrovatus Motschulsky and Queda Sharp resolved as sister groups and not closely related to Methlini van den Branden, 3) support for close relationship of Pachydrus Sharp (Pachydrini Biström, Nilsson and Wewalka) with Hyphydrini Sharp, 4) paraphyly of Hygrotus Stephens sensu lato with the relationship H. (Coelambus) Thomson + (Hygrotus sensus stricto + Hydrovatini)) suggesting recognition of Coelambus and Hygrotus as separate genera, 5) close relationship between the Australian genera of Hydroporini and Hyphydrini and 6) the nesting of Vatellini within a group of Hydroporini.

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.

A new species of Zangerlia (Testudines: Nanhsiungchelyidae) from the Upper Cretaceous redbeds at Bayan Mandahu, Inner Mongolia, and the relationships of the genus

1996 ◽  
Vol 33 (4) ◽  
pp. 526-540 ◽  
Author(s):  
Donald Brinkman ◽  
Jiang-Hua Peng
Keyword(s):  
New Species ◽  
Inner Mongolia ◽  
Upper Cretaceous ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Group Relationship ◽  
The Family ◽  
A New Species

Zangerlia neimongolensis sp.nov. is described on the basis of material from the Upper Cretaceous redbeds at Bayan Mandahu in Inner Mongolia. Zangerlia neimongolensis is similar to Zangerlia testudinimorpha in the proportions of the carapace and plastron and presence of a knob at the posterior end of the neural series, but differs from it in the arrangement of scutes covering the bridge. The placement of Zangerlia in the Nanhsiungchelyidae is supported by derived features of the bridge peripherals and plastral scutes shared by Z. neimongolensis, Basilemys, and Nanhsiungchelys. These are the presence of ventrally expanded sixth inframarginal scutes, humeral scutes that are narrow at the midline and expanded laterally, pectoral scutes that are wide at the midline and narrow laterally, and large rectangular abdominal scutes. The skull of Zangerlia is more primitive than that of Nanhsiungchelys, the only other member of the family for which a skull is known. It shows extensive emargination of the temporal and cheek regions and the absence of a large, tubular external narial opening. A cladistic analysis of the Trionychoidea using Zangerlia as the representative of the Nanhsiungchelyidae suggests a sister-group relationship between the Nanhsiungchelyidae and Adocidae.

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