Revised morphology of Pycnonemosaurus nevesi Kellner & Campos, 2002 (Theropoda: Abelisauridae) and its phylogenetic relationships

Zootaxa ◽  
2017 ◽  
Vol 4276 (1) ◽  
pp. 1 ◽  
Author(s):  
RAFAEL DELCOURT

Abelisaurid theropods were most abundant in the Gondwana during the Cretaceous Period. Pycnonemosaurus nevesi Kellner & Campos, 2002 was the first abelisaurid dinosaur described from the Bauru Group (Brazil, Upper Cretaceous). Nevertheless, its initial description was based on the comparison of a restricted number of remains with other abelisaurids. In this paper, I present a new description of the morphology of Pycnonemosaurus nevesi, including three new caudal transverse processes and a discussion of several new characteristics based on perspectives derived from recently described abelisauroids. Pycnonemosaurus nevesi differs from other abelisaurids based on the following features: a pubis with a small rounded foot and a ventrally-bowed anterior distal end; posterior caudal vertebrae with a hook-shaped transverse process that has an anterodistal expansion that is short and bowed; a strong and massive tibia with a well-developed lateral malleolus that is ventrally expanded. The unfused sutures represent signs of skeletal immaturity, but the specific ontogenetic stage is still uncertain. The current phylogenetic analysis suggests strongly relationship within Pycnonemosaurus and the most-derived abelisaurids (e.g Carnotaurus and Aucasaurus). 

2020 ◽  
Vol 106 ◽  
pp. 104259
Author(s):  
Galuber Oliveira Cunha ◽  
Rodrigo Miloni Santucci ◽  
Marco Brandalise de Andrade ◽  
Carlos Eduardo Maia de Oliveira

Zootaxa ◽  
2011 ◽  
Vol 3085 (1) ◽  
pp. 1 ◽  
Author(s):  
RODRIGO M. SANTUCCI ◽  
ANTONIO C. DE ARRUDA-CAMPOS

Remains of a new titanosaur, Aeolosaurus maximus sp. nov., from the Adamantina Formation (Upper Cretaceous), Bauru Group, São Paulo State of Brazil are described. The new species is represented by a single partially articulated skeleton and is characterized by having a well-developed posterior protuberance below the articular area on the anterior and middle haemal arches and a lateral bulge on the distal portion of the articular process of the mid-posterior haemal arches. It shares with other Aeolosaurus species the presence of prezygapophyses curved downward on anterior caudal vertebrae and haemal arches with double articular facets set in a concave posterodorsal surface. These two characteristics are interpreted here as synapomorphies for the genus Aeolosaurus. The new diagnosis for the genus Aeolosaurus does not support the inclusion of Gondwanatitan within Aeolosaurus as previously proposed by some authors. The phylogenetic analysis recovered the two Aeolosaurus from Argentina as sister groups with A. maximus and Gondwanatitan as progressively more basal taxa (Gondwanatitan (A. maximus (A. rionegrinus, A. colhuehuapensis))). Additionally, according to the results of the phylogenetic analysis performed in this work, the taxa Panamericansaurus, Rinconsaurus, and Maxakalisaurus are also nested within Aeolosaurini, being more basal than Aeolosaurus and Gondwanatitan. On the basis of the stratigraph-ical range of the Aeolosaurus occurrences in Argentina and the age proposals based on microfossils for the Bauru Group, it is assumed a Campanian–Maastrichtian age for the top of the Adamantina Formation for the Monte Alto region in São Paulo State and the bottom of the Marília Formation in Peirópolis, Minas Gerais State—the places where Aeolosaurus remains have been reported in Brazil.


2000 ◽  
Vol 74 (5) ◽  
pp. 915-937 ◽  
Author(s):  
Michael S. Y. Lee ◽  
Michael W. Caldwell

The poorly-known, long bodied, limb-reduced marine lizard Adriosaurus suessi Seeley, 1881, is reassessed. Adriosaurus and a number of other marine lizards are known from Upper Cretaceous (Upper Cenomanian-Lower Turonian) marine carbonate rocks exposed along the Dalmatian coast of the Adriatic Sea, from Komen, Slovenia, to Hvar Island, Croatia. A revised vertebral count reveals 10 cervical, 29 dorsal, and at least 65 caudal vertebrae. The projections previously interpreted as hypapophyses are instead transverse processes. Openings on the anterior part of the skull, previously described as external nares, are probably internal nares. Important features not noted previously include accessory articulations on all presacral vertebrae, pachyostosis of dorsal vertebrae and ribs, and the presence of two pygal vertebrae. Phylogenetic analysis of 258 osteological characters and all the major squamate lineages suggests that Adriosaurus and dolichosaurs are successive sister-taxa to snakes. This is consistent with their long-bodied, limb-reduced morphology being intermediate between typical marine squamates (e.g., mosasaurs) and primitive marine snakes (pachyophiids). The analysis further reveals that up to five successive outgroups to living snakes (pachyophiids, Adriosaurus, dolichosaurs, Aphanizocnemus, and mosasauroids) are all marine, suggesting a marine (or at least, semi-aquatic) phase in snake origins. These phylogenetic results are robust whether multistate characters are ordered or unordered, thus refuting recent suggestions that snakes cluster with amphisbaenians and dibamids (rather than aquatic lizards) if multistate characters are left unordered. Also, the recent suggestion that Pachyrhachis shares synapomorphies with advanced snakes (macrostomatans) is shown to be poorly supported, because the reinterpretations of the relevant skull elements are unlikely and, even if accepted, the character states proposed to unite Pachyrhachis and advanced snakes are also present in more basal snakes and/or the nearest lizard outgroups, and are consequently primitive for snakes.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 668
Author(s):  
Tinghao Yu ◽  
Yalin Zhang

More studies are using mitochondrial genomes of insects to explore the sequence variability, evolutionary traits, monophyly of groups and phylogenetic relationships. Controversies remain on the classification of the Mileewinae and the phylogenetic relationships between Mileewinae and other subfamilies remain ambiguous. In this study, we present two newly completed mitogenomes of Mileewinae (Mileewa rufivena Cai and Kuoh 1997 and Ujna puerana Yang and Meng 2010) and conduct comparative mitogenomic analyses based on several different factors. These species have quite similar features, including their nucleotide content, codon usage of protein genes and the secondary structure of tRNA. Gene arrangement is identical and conserved, the same as the putative ancestral pattern of insects. All protein-coding genes of U. puerana began with the start codon ATN, while 5 Mileewa species had the abnormal initiation codon TTG in ND5 and ATP8. Moreover, M. rufivena had an intergenic spacer of 17 bp that could not be found in other mileewine species. Phylogenetic analysis based on three datasets (PCG123, PCG12 and AA) with two methods (maximum likelihood and Bayesian inference) recovered the Mileewinae as a monophyletic group with strong support values. All results in our study indicate that Mileewinae has a closer phylogenetic relationship to Typhlocybinae compared to Cicadellinae. Additionally, six species within Mileewini revealed the relationship (U. puerana + (M. ponta + (M. rufivena + M. alara) + (M. albovittata + M. margheritae))) in most of our phylogenetic trees. These results contribute to the study of the taxonomic status and phylogenetic relationships of Mileewinae.


1995 ◽  
Vol 69 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Daniel B. Blake ◽  
Keith Sturgeon

Aldebarania arenitea (Astropectinidae; Asteroidea; Echinodermata) is described from the Rocky Point Member of the Maastrichtian (Upper Cretaceous) Peedee Formation of North Carolina. A turbulent, shallow-water environment is suggested by sedimentary features, a diverse marine fauna, and the morphology of Aldebarania. Aldebarania appears to be a partial ecological equivalent of living Astropecten and Luidia; however, phylogenetic relationships within the Astropectinidae are unstudied and the origin of similarities is unknown.


2005 ◽  
Vol 26 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Francisca do Val ◽  
Paulo Nuin

AbstractThe systematics and phylogenetic relationships of the family Leptodactylidae are controversial as is the intrafamilial phylogeny of the leptodactylids. Here we analyze the relationships of the leptodactylid subfamily Hylodinae. This subfamily has been considered to be monophyletic and composed of three genera, Hylodes, Crossodactylus and Megaelosia. In the present study 49 characters were used, based on different studies on Leptodactylidae phylogeny. Maximum parsimony methods with unweighted and successively weighted characters were used to estimate the phylogeny of the Hylodinae. Upon analysis, the data provided further evidence of the monophyletic status of the three genera, with Megaelosia being the basal genus and the other two genera being sister taxa. The analysis with successive weighting results in a more resolved topology of the species subgroups of the genus Hylodes and separates this genus from Crossodactylus and confirms that the hylodines are monophyletic.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246620
Author(s):  
Alexander Averianov ◽  
Hans-Dieter Sues

Dzharatitanis kingi gen. et sp. nov. is based on an isolated anterior caudal vertebra (USNM 538127) from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan. Phylogenetic analysis places the new taxon within the diplodocoid clade Rebbachisauridae. This is the first rebbachisaurid reported from Asia and one of the youngest rebbachisaurids in the known fossil record. The caudal is characterized by a slightly opisthocoelous centrum, ‘wing-like’ transverse processes with large but shallow PRCDF and POCDF, and the absence of a hyposphenal ridge and of TPRL and TPOL. The neural spine has high SPRL, SPDL, SPOL, and POSL and is pneumatized. The apex of neural spine is transversely expanded and bears triangular lateral processes. The new taxon shares with Demandasaurus and the Wessex rebbachisaurid a high SPDL on the lateral side of the neural spine, separated from SPRL and SPOL. This possibly suggests derivation of Dzharatitanis from European rebbachisaurids. This is the second sauropod group identified in the assemblage of non-avian dinosaurs from the Bissekty Formation, in addition to a previously identified indeterminate titanosaurian.


1990 ◽  
Vol 38 (5) ◽  
pp. 519 ◽  
Author(s):  
PR Baverstock ◽  
M Krieg ◽  
J Birrell ◽  
GM Mckay

Microcomplement fixation of albumin was used to examine the phylogenetic relationships among the ringtail possums, family Pseudocheiridae. Phylogenetic analysis of the data supports the hypothesis of at least three distinct clades within the family: one containing Petauroides and Hemibelideus; a second consisting of Pseudocheirus herbertensis, Ps. forbesi, Ps. mayeri, and Ps. canescens; and a third containing Ps. archeri, Ps. corinnae, Ps. cupreus and Ps. dahli. The data have not resolved the phylogenetic position of Ps. peregrinus, which may either form a separate clade or lie close to the Ps. archeri clade.


Zootaxa ◽  
2009 ◽  
Vol 2164 (1) ◽  
pp. 21-32 ◽  
Author(s):  
FRANCISCO J. DE FIGUEIREDO

Clupeomorph fishes are largely diversified and widespread in Cretaceous strata of northeastern Brazil. They are represented by basal clupeiforms, †ellimmichthyiforms, and advanced clupeoids. In this paper, a new clupeoid fish, †Nolfia riachuelensis sp. nov., is described based on a specimen found in marine shale yielded in the Taquari Member (Albian) of Riachuelo Formation, Sergipe-Alagoas Basin. Although partially preserved (most of skull is lacking), the fish shows many informative characters, particularly in the axial skeleton. The fish is morphologically very similar to †Nolfia kwangoensis, a clupeoid fish originally described from marine deposit from the Upper Cretaceous (Cenomanian) of Kipala, Democratic Republic of Congo, with which it shares: 18 caudal vertebrae; long and cylindrical pleural ribs; posteriormost pleural ribs supported by long parapophyses and gradually decreasing in size posteriorly; very reduced ural centra; presence of long and distally congruent neural spines of third, second, and first preural centra; three uroneural bones (the first probably forming the pleurostyle). Otherwise, †Nolfia riachuelensis sp. nov. differs from other clupeomorphs by a unique combination of features. The number of supraneural bones, aligned rod-like postcleithra, less than 30 rays in the anal fin, and derived absence of dorsal scutes indicate its placement within Clupeidae. As far as is known, †Nolfia riachuelensis sp. nov. is the most ancient clupeoid fish known from the fossil record.


2016 ◽  
Vol 14 (1) ◽  
Author(s):  
Alejandro Londoño-Burbano ◽  
Roberto E. Reis

ABSTRACT A taxonomic revision and phylogenetic analysis were completed for Dasyloricaria . The genus includes three valid species: D . filamentosa and D . latiura previously included in the genus, and a new species described herein. Dasyloricaria have a restricted trans-Andean distribution, with D . filamentosa occurring at the lower and middle Magdalena, lower Cauca, and Sinu in Colombia, and lago Maracaibo basin in Colombia and Venezuela; D . latiura in the Atrato and the Tuyra basins in Colombia and Panama, respectively; and the new species in the upper and middle Magdalena basin in Colombia. New synonyms for D . filamentosa and D . latiura are proposed, and a lectotype is designated for the latter. Dasyloricaria is herein recognized as monophyletic, with D . filamentosa as the sister group of D . latiura , and the new speciesas sister to that clade. Spatuloricaria is hypothesized to be the sister group of Dasyloricaria based on synapomorphies of the neurocranium, branchial arches and external morphology features. The subtribe Rineloricariina was partially corroborated through the phylogenetic analysis. An identification key for the species of Dasyloricaria is provided.


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