Osteology of Hemigrammocypris neglecta (Teleostei: Cypriniformes) with comments on its systematic position

Zootaxa ◽  
2021 ◽  
Vol 4995 (1) ◽  
pp. 147-160
Author(s):  
TAIKI ITO ◽  
KAZUO HOSHINO ◽  
KAZUMI HOSOYA
Keyword(s):  
Systematic Position ◽  
Cyprinid Fish ◽  
Sister Taxon

Hemigrammocypris neglecta is a small-sized cyprinid fish that is endemic to Japan and the sole member of the genus Hemigrammocypris. We examined the osteological features of the species, and its relationships with related genera are discussed. The present data suggest that H. neglecta is most likely the sister taxon of Metzia lineata. This relationship is supported by one possible synapomorphy: the presence of a postepiphysial fontanelle, which is absent in all other Xenocypridinae.  

scholarly journals A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China

Zootaxa ◽  
2010 ◽  
Vol 2403 (1) ◽  
pp. 1 ◽  
Author(s):  
XING XU ◽  
JONAH N. CHOINIERE ◽  
MICHAEL PITTMAN ◽  
QINGWEI TAN ◽  
DONG XIAO ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Inner Mongolia ◽  
Upper Cretaceous ◽  
Systematic Position ◽  
Sister Taxon ◽  
New Taxon ◽  
Salient Features

We describe a new dromaeosaurid theropod from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia. The new taxon, Linheraptor exquisitus gen. et sp. nov., is based on an exceptionally well-preserved, nearly complete skeleton. This specimen represents the fifth dromaeosaurid taxon recovered from the Upper Cretaceous Djadokhta Formation and its laterally equivalent strata, which include the Wulansuhai Formation, and adds to the known diversity of Late Cretaceous dromaeosaurids. Linheraptor exquisitus closely resembles the recently reported Tsaagan mangas. Uniquely among dromaeosaurids, the two taxa share a large, anteriorly located maxillary fenestra and a contact between the jugal and the squamosal that excludes the postorbital from the infratemporal fenestra. These features suggest a sister-taxon relationship between L. exquisitus and T. mangas, which indicates the presence of a unique dromaeosaurid lineage in the Late Cretaceous of Asia. A number of cranial and dental features seen in L. exquisitus and T. mangas, and particularly some postcranial features of L. exquisitus, suggest that these two taxa are probably intermediate in systematic position between known basal and derived dromaeosaurids. The discovery of Linheraptor exquisitus is thus important for understanding the evolution of some salient features seen in the derived dromaeosaurids.

Re-evaluation of the historic Canadian fossil Bathygnathus borealis from the Early Permian of Prince Edward Island

2015 ◽  
Vol 52 (12) ◽  
pp. 1109-1120 ◽  
Author(s):  
Kirstin S. Brink ◽  
Hillary C. Maddin ◽  
David C. Evans ◽  
Robert R. Reisz
Keyword(s):  
New Species ◽  
Prince Edward Island ◽  
Scientific Literature ◽  
Cladistic Analysis ◽  
Systematic Position ◽  
Sister Taxon ◽  
Lower Permian ◽  
Early Permian ◽  
Maxillary Dentition

The holotype and only known specimen of Bathygnathus borealis is a partial snout with maxillary dentition of a presumed sphenacodontid from the Lower Permian (Artinskian 283–290 Ma) redbeds of Prince Edward Island, Canada. Due to its incomplete nature, assessment of the taxon’s systematic position within a cladistic analysis had never been performed. However, recent recognition of the phylogenetic utility of tooth characters in sphenacodontids now allows for a modern phylogenetic evaluation of B. borealis. Results show that B. borealis is the sister taxon of Dimetrodon grandis, which is supported by dental characters: crowns with mesial and distal denticles and roots elongate, lacking plicidentine. An autapomorphy of B. borealis is the large facial exposure of the septomaxilla. As Bathygnathus has priority over Dimetrodon in the scientific literature, we suggest a reversal of precedence is required to preserve the familiar name Dimetrodon and to maintain universality, thus recognizing the new species Dimetrodon borealis.

scholarly journals The systematic position of the enigmatic thyreophoran dinosaurParanthodon africanus, and the use of basal exemplifiers in phylogenetic analysis

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4529 ◽  
Author(s):  
Thomas J. Raven ◽  
Susannah C.R. Maidment
Keyword(s):  
South Africa ◽  
Phylogenetic Analysis ◽  
Lower Cretaceous ◽  
Phylogenetic Analyses ◽  
Systematic Position ◽  
Type Material ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Taxonomic Assignment

The first African dinosaur to be discovered,Paranthodon africanuswas found in 1845 in the Lower Cretaceous of South Africa. Taxonomically assigned to numerous groups since discovery, in 1981 it was described as a stegosaur, a group of armoured ornithischian dinosaurs characterised by bizarre plates and spines extending from the neck to the tail. This assignment has been subsequently accepted. The type material consists of a premaxilla, maxilla, a nasal, and a vertebra, and contains no synapomorphies of Stegosauria. Several features of the maxilla and dentition are reminiscent of Ankylosauria, the sister-taxon to Stegosauria, and the premaxilla appears superficially similar to that of some ornithopods. The vertebral material has never been described, and since the last description of the specimen, there have been numerous discoveries of thyreophoran material potentially pertinent to establishing the taxonomic assignment of the specimen. An investigation of the taxonomic and systematic position ofParanthodonis therefore warranted. This study provides a detailed re-description, including the first description of the vertebra. Numerous phylogenetic analyses demonstrate that the systematic position ofParanthodonis highly labile and subject to change depending on which exemplifier for the clade Stegosauria is used. The results indicate that the use of a basal exemplifier may not result in the correct phylogenetic position of a taxon being recovered if the taxon displays character states more derived than those of the basal exemplifier, and we recommend the use, minimally, of one basal and one derived exemplifier per clade.Paranthodonis most robustly recovered as a stegosaur in our analyses, meaning it is one of the youngest and southernmost stegosaurs.

scholarly journals The systematic position of the enigmatic thyreophoran dinosaur Paranthodon africanus, and the use of basal exemplifiers in phylogenetic analysis

2018 ◽  
Author(s):  
Tom Raven ◽  
Susannah C. R. Maidment
Keyword(s):  
South Africa ◽  
Phylogenetic Analysis ◽  
Lower Cretaceous ◽  
Phylogenetic Analyses ◽  
Systematic Position ◽  
Type Material ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Taxonomic Assignment

The first African dinosaur to be discovered, Paranthodon africanus was found in 1845 in the Lower Cretaceous of South Africa. Taxonomically assigned to numerous groups since discovery, in 1981 it was described as a stegosaur, a group of armoured ornithischian dinosaurs characterised by bizarre plates and spines extending from the neck to the tail. This assignment has been subsequently accepted. The type material consists of a premaxilla, maxilla, a nasal, and a vertebra, and contains no synapomorphies of Stegosauria. Several features of the maxilla and dentition are reminiscent of Ankylosauria, the sister-taxon to Stegosauria, and the premaxilla appears superficially similar to that of some ornithopods. The vertebral material has never been described, and since the last description of the specimen, there have been numerous discoveries of thyreophoran material potentially pertinent to establishing the taxonomic assignment of the specimen. An investigation of the taxonomic and systematic position of Paranthodon is therefore warranted. This study provides a detailed re-description, including the first description of the vertebra. Numerous phylogenetic analyses demonstrate that the systematic position of Paranthodon is highly labile and subject to change depending on which exemplifier for the clade Stegosauria is used. The results indicate that the use of a basal exemplifier may not result in the correct phylogenetic position of a taxon being recovered if the taxon displays character states more derived than those of the basal exemplifier, and we recommend the use, minimally, of one basal and one derived exemplifier per clade. Paranthodon is most robustly recovered as a stegosaur in our analyses, meaning it is one of the youngest and southernmost stegosaurs.

The first appearance of Troodon in the Upper Cretaceous site of Danek Bonebed, and a reevaluation of troodontid quantitative tooth morphotypes

2014 ◽  
Vol 51 (11) ◽  
pp. 1039-1044 ◽  
Author(s):  
Angelica Torices ◽  
Gregory F. Funston ◽  
Shannon T. Kraichy ◽  
Philip J. Currie
Keyword(s):  
Upper Cretaceous ◽  
Systematic Position ◽  
Sister Taxon ◽  
Theropod Dinosaur ◽  
Single Tooth ◽  
Horseshoe Canyon Formation ◽  
Upper Campanian

The systematic position of the small theropod dinosaur Troodon has had a confusing history and has been identified at different times as a lizard, a pachycephalosaurid, and a coelurosaurid. Troodon is now most commonly considered as a sister taxon to Dromeaosauridae, within Maniraptora. This study records the first evidence of Troodon in the Danek bonebed, an organic-rich member of the upper Campanian Horseshoe Canyon Formation. A single tooth (UALVP 55489) was recovered during the 2012 dig season, and it is exceptionally well-preserved. Its discovery prompted a reevaluation of variation within troodontid teeth in Alberta; it is compared here with 110 troodontid teeth from the Dinosaur Park, Horseshoe Canyon, and Wapiti formations. The results show that no distinctive morphotypes can be separated, in contrast to the results of other studies. This suggests that either troodontid teeth are not sufficiently different for identifying different species or that only one troodontid taxon is present in the Campanian of Alberta.

The new genera Procydrela and Rotundrela, sister taxa for Storenomorphinae and Cydrelinae (Araneae: Zodariidae)

1999 ◽  
Vol 30 (2) ◽  
pp. 225-240 ◽  
Author(s):  
Rudy Jocqué
Keyword(s):  
South Africa ◽  
New Species ◽  
Unique Feature ◽  
Systematic Position ◽  
Sister Taxon ◽  
New Genera ◽  
Two New Species

AbstractThe new genera Procydrela and Rotundrela are described from the Cape region in South Africa. Each genus is represented by two new species, the former by P. procursor (♂,♀) and P rimacola (♂), the second one by R. rotunda (♂,♀) and R. orbiculata (♂,♀). The systematic position of Prncydrela is not entirely clear but it may be regarded as the sister taxon of Cydrelinae and Storenomorphinae combined, whereas Rotundrela belongs in the Cydrelinae and appears to be the sister taxon of the remaining genera in that subfamily. Both genera possess a prolateral abdominal sigillum. The laterally compressed, disk-shaped palpal bulbus of Rotundrela is a unique feature and not found elsewhere in spiders.

CARABHYDRUS MUBBOONUS, A NEW SPECIES OF RHEOPHILIC WATER BEETLE (COLEOPTERA: DYTISCIDAE) FROM QUEENSLAND, AUSTRALIA

1994 ◽  
Vol 126 (3) ◽  
pp. 895-906 ◽  
Author(s):  
David J. Larson ◽  
Ross I. Storey
Keyword(s):  
New Species ◽  
Systematic Position ◽  
Sister Taxon ◽  
Water Beetle ◽  
Closed Forest ◽  
Forest Streams ◽  
A New Species

AbstractCarabhydrus mubboonus, new species (Coleopiera; Dytiscidae; Hydroporinae) from small. closed, forest streams of the Great Dividing Range of northern Queensland. Australia, is described. A key to the five described species of Carabhydrus is presented. The systematic position of the genus Carabhydrus Watts is reviewed. Although it resembles members of the Bidessini Sharp in some characters, others indicate the genus belongs in the tribe Hydroporini Erichson (1837) and has affinities with the subtribe Sternopriscina Van den Branden, However, no clear synapomorphy was discovered that unequivocally identifies the sister taxon.

The systematic position of the genusCalyptrotheca Gilg (Portulacaceae)

1986 ◽  
Vol 97 (11-12) ◽  
pp. 767-769
Author(s):  
Bio Louis Nyananyo
Keyword(s):  
Systematic Position
Sign in / Sign up

Export Citation Format

Share Document