The anatomy and systematic position of the theropod dinosaurChilantaisaurus tashuikouensisHu, 1964 from the Early Cretaceous of Alanshan, People's Republic of China

2008 ◽  
Vol 145 (6) ◽  
pp. 778-789 ◽  
Author(s):  
ROGER B. J. BENSON ◽  
XU XING
Keyword(s):  
Upper Cretaceous ◽  
Phylogenetic Analyses ◽  
Distal Humerus ◽  
Systematic Position ◽  
Theropod Dinosaur ◽  
Anatomical Features ◽  
Republic Of China ◽  
Tibial Length ◽  
Basal Position

AbstractThere is little consensus on the systematic position of the colossal theropod dinosaurChilantaisaurus tashuikouensisfrom the Cretaceous (Aptian–?Albian or Upper Cretaceous) Ulansuhai Formation of Inner Mongolia, which has been recovered as a derived member of both Allosauroidea and Spinosauroidea by numerical phylogenetic analyses. Redescription of the type material ofC. tashuikouensisreveals an unusual combination of morphological features that render determination of its systematic position problematic. It possesses anatomical features that have been proposed as synapomorphies of Neotetanurae: a preacetabular fossa on the ilium, and a wedge-shaped cross-section of the shaft of the third metatarsal. It also shares some features with specific allosauroid taxa: a pronounced ulnar epicondyle on the humerus, and a prominent medial shelf bounding the preacetabular fossa on the ilium (also present in tyrannosauroids). However, it lacks some features that are present in all other allosauroids: a marked depression on the anterior surface of the distal humerus adjacent to the ulnar condyle, and a humerus that is less than 0.4 times the length of the femur; it furthermore possesses a tibial astragalar facet that is approximately 10% of the tibial length, which suggests a more basal position within Tetanurae.Chilantaisaurusshares certain features with some spinosauroids: an enlarged and elongated first manual ungual, and a suprastragalar buttress that has been modified to a vertical ridge, but these characters are not unique to spinosauroids. A highly reduced fourth trochanter may be an autapomorphy ofChilantaisaurus, as has previously been suggested, or unite the taxon with Coelurosauria in an entirely novel grouping. On the basis of these observations it is likely thatChilantaisaurusis a neotetanuran, but unlikely that it is an allosauroid.Chilantaisaurusmay belong to an alternative lineage of very large theropods that continued into the Cretaceous from the diversification of basal neotetanurans during the Middle Jurassic.

Sineoamphisbaena hexatabularis, an amphisbaenian (Diapsida: Squamata) from the Upper Cretaceous redbeds at Bayan Mandahu (Inner Mongolia, People's Republic of China), and comments on the phylogenetic relationships of the Amphisbaenia

1996 ◽  
Vol 33 (4) ◽  
pp. 541-577 ◽  
Author(s):  
Xiao-Chun Wu ◽  
Donald B. Brinkman ◽  
Anthony P. Russell
Keyword(s):  
Central Asia ◽  
Phylogenetic Relationships ◽  
Inner Mongolia ◽  
Upper Cretaceous ◽  
Phylogenetic Analyses ◽  
Temporal Region ◽  
People's Republic Of China ◽  
Way Of Life ◽  
Lacustrine Environment ◽  
Republic Of China

Sineoamphisbaena hexatabularis Wu et al., 1993 is the earliest known amphisbaenian represented by well-preserved cranial and postcranial material. It reveals a mosaic of generalized lizard-like features and amphisbaenian characters. Most distinctive of the latter are features of cranial consolidation adaptive for a fossorial way of life. Phylogenetic analyses strongly confirm the monophyly of the Amphisbaenia inclusive of S. hexatabularis. The Amphisbaenia is diagnosed by a suite of apomorphic characters. The available evidence suggests a probable Amphisbaenia–Macrocephalosauridae relationship within the Scincomorpha. This is supported primarily by the unique modifications of the palate and temporal region of the skull. It is argued here that the Amphisbaenia evolved in Central Asia during the Cretaceous, in response to the transition from a perennial lacustrine environment to a dry, semiarid eolian environment. The relatively primitive morphology indicates that S. hexatabularis was not permanently subterranean. The further derived modifications of later forms are associated with tunneling in an environment of more compact soils.

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 Frequency of HIV-1 Infection in Iranian Children and Determination of the Transmitted Drug Resistance in Treatment-Naïve Children

2020 ◽  
Vol 17 (6) ◽  
pp. 397-407
Author(s):  
Maryam Jarchi ◽  
Farah Bokharaei-Salim ◽  
Maryam Esghaei ◽  
Seyed Jalal Kiani ◽  
Fatemeh Jahanbakhsh ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Pediatric Patients ◽  
Phylogenetic Analyses ◽  
Rna Extraction ◽  
Transmitted Drug Resistance ◽  
The Arts ◽  
Treatment Naïve ◽  
Iranian Children ◽  
Hiv 1

Background: The advent of resistance-associated mutations in HIV-1 is a barrier to the success of the ARTs. Objective: In this study, the abundance of HIV-1 infection in Iranian children, and also detection of the TDR in naïve HIV-1 infected pediatric (under 12 years old) were evaluated. Materials: From June 2014 to January 2019, a total of 544 consecutive treatment-naïve HIV-1- infected individuals enrolled in this study. After RNA extraction, amplification, and sequencing of the HIV-1 pol gene, the DRM and phylogenetic analysis were successfully performed on the plasma specimens of the ART-naïve HIV-1-infected-children under 12 years old. The DRMs were recognized using the Stanford HIV Drug Resistance Database. Results: Out of the 544 evaluated treatment-naïve HIV-1-infected individuals, 15 (2.8%) cases were children under 12 years old. The phylogenetic analyses of the amplified region of pol gene indicated that all of the 15 HIV-1-infected pediatric patients were infected by CRF35_AD, and a total of 13.3% (2/15) of these children were infected with HIV-1 variants with SDRMs (one child harbored two related SDRMs [D67N, V179F], and another child had three related SDRMs [M184V, T215F, and K103N]), according to the last algorithm of the WHO. No PIs-related SDRMs were observed in HIV-1-infected children. Conclusion: The current study demonstrated that a total of 13.3% of treatment-naïve HIV-1-infected Iranian pediatrics (under 12 years old) were infected with HIV-1 variants with SDRMs. Therefore, it seems that screening to recognize resistance-associated mutations before the initiation of ARTs among Iranian children is essential for favorable medication efficacy and dependable prognosis.

scholarly journals Molecular Epidemiology and Whole-Genome Analysis of Bovine Foamy Virus in Japan

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1017
Author(s):  
Hirohisa Mekata ◽  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
Takayuki Miyazawa
Keyword(s):  
Phylogenetic Analyses ◽  
Foamy Virus ◽  
Pcr Analysis ◽  
Whole Genome ◽  
Genome Sequences ◽  
Whole Genome Analysis ◽  
Virus Family ◽  
Bovine Foamy Virus ◽  
Novel Genotype

Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.

Diversity, morphology, and phylogeny of coleoid cephalopods from the Upper Cretaceous Plattenkalks of Lebanon-Part I: Prototeuthidina

2011 ◽  
Vol 85 (2) ◽  
pp. 234-249 ◽  
Author(s):  
Dirk Fuchs ◽  
Neal Larson
Keyword(s):  
Digestive Tract ◽  
Upper Cretaceous ◽  
Soft Part ◽  
Phylogenetic Analyses ◽  
Early Jurassic ◽  
The Other ◽  
Large Collection ◽  
Shaped Body ◽  
Cretaceous Deposits

Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species:Dorateuthis syriacaandBoreopeltis smithin. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge ofD. syriaca.Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial.Boreopeltis smithin. sp. is erected on the basis of its comparatively wideParaplesioteuthis-like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early JurassicParaplesioteuthisand leads toPlesioteuthisandDorateuthis.The other lineage is morphologically more conservative and leads toBoreopeltis.

Systematic status of Campydora Cobb, 1920 (Nematoda: Campydorina)

Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers
Keyword(s):  
Maximum Likelihood ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Maximum Parsimony ◽  
Phylogenetic Analyses ◽  
Small Subunit ◽  
Systematic Position ◽  
Nominal Species ◽  
Competing Hypotheses ◽  
Small Subunit Ribosomal Dna

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.

Mitogenome of Alaudala cheleensis (Passeriformes: Alaudidae) and comparative analyses of Sylvioidea mitogenomes

Zootaxa ◽  
2021 ◽  
Vol 4952 (2) ◽  
pp. 331-353
Author(s):  
CHAO YANG ◽  
LE ZHAO ◽  
QINGXIONG WANG ◽  
HAO YUAN ◽  
XUEJUAN LI ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Gene Order ◽  
Phylogenetic Relationships ◽  
Gene Rearrangement ◽  
Phylogenetic Analyses ◽  
Protein Coding ◽  
Comparative Analyses ◽  
Protein Coding Genes ◽  
Basal Position

To gain a better understanding of mitogenome features and phylogenetic relationships in Sylvioidea, a superfamily of Passerida, suborder Passeri, Passeriformes, the whole mitogenome of Alaudala cheleensis Swinhoe (Alaudidae) was sequenced, a comparative mitogenomic analysis of 18 Sylvioidea species was carried out, and finally, a phylogeny was reconstructed based on the mitochondrial dataset. Gene order of the A. cheleensis mitogenome was similar to that of other Sylvioidea species, including the gene rearrangement of cytb-trnT-CR1-trnP-nad6-trnE-remnant CR2-trnF-rrnS. There was slightly higher A+T content than that of G+C in the mitogenome, with an obvious C skew. The ATG codon initiated all protein-coding genes, while six terminating codons were used. The secondary structure of rrnS contained three domains and 47 helices, whereas rrnL included six domains and 60 helices. All tRNAs could be folded into a classic clover-leaf secondary structure except for trnS (AGY). The CR1 could be divided into three domains, including several conserved boxes (C-string, F, E, D, C and B-box, Bird similarity box, CSB1). Comparative analyses within Sylvioidea mitogenomes showed that most mitochondrial features were consistent with that of the A. cheleensis mitogenome. The basal position of the Alaudidae within the Sylvioidea in our phylogenetic analyses is consistent with other recent studies. 

I.—Description of the Cretaceous Saw-Fish Sclerorhynchus Atavus

1892 ◽  
Vol 9 (12) ◽  
pp. 529-534 ◽  
Author(s):  
Arthur Smith Woodward
Keyword(s):  
Upper Cretaceous ◽  
British Museum ◽  
Systematic Position ◽  
Complex Nature ◽  
The Family

In the “Catalogue of Fossil Fishes in the British Museum“ (pt. i. 1889, p. 76, pl. iii. fig. 1), the imperfect rostrum of a Selachian fish from the Upper Cretaceous of Mount Lebanon was described under the new generic and specific name of Sclerorhynchm atavus. Presenting some resemblances to the rostrum both of the typical saw-fish (Prislis) and of PristiopJtorus, hesitation was expressed in determining the systematic position of the genus to which the fossil pertained; but from the apparently complex nature of the rostral cartilages and the absence of extended prepalatines, it was deemed advisable to place the fish provisionally in the family of Pristidæ.

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