scholarly journals New turtle remains from the Late Cretaceous of Monte Alto-SP, Brazil, including cranial osteology, neuroanatomy and phylogenetic position of a new taxon

2017 ◽  
Author(s):  
Gabriel S. Ferreira ◽  
Fabiano Vidoi Iori ◽  
Guilherme Hermanson ◽  
Max C. Langer

A high diversity of land vertebrates is known from the Late Cretaceous deposits of the Bauru Basin, Brazil, including at least five turtle taxa, all belonging tothe cladePodocnemidoidae. Some of the richest fossil sites of this basin are in the area of Monte Alto, which yielded several squamate, dinosaur, and crocodyliform taxa. Yet, the single turtle reported so far from this area was only briefly described. Here, we further describe that specimen, a complete but very crushed shell, as well as a partial skull, both found in outcrops of the Adamantina Formation. Comparison of the shell to other podocnemidoid taxa reveals its affinities to Roxochelys wanderleyi, a turtle originally described from that same stratigraphic unit. The comparative description of the skull and its inclusion in a phylogenetic study, supports the proposal of a new taxon representing a lineage (Peiropemydodda) so far known only from the Marília Formation of the Bauru Basin and the early Paleocene of Bolivia. The digitally reconstructed endocast and inner ear of the new taxon were also described, as not previously done fora fossil pleurodire.

PalZ ◽  
2018 ◽  
Vol 92 (3) ◽  
pp. 481-498 ◽  
Author(s):  
Gabriel S. Ferreira ◽  
Fabiano V. Iori ◽  
Guilherme Hermanson ◽  
Max C. Langer

Zootaxa ◽  
2021 ◽  
Vol 4981 (3) ◽  
pp. 449-468
Author(s):  
S.R. GANESH ◽  
ASHOK KUMAR MALLIK ◽  
N.S. ACHYUTHAN ◽  
KARTIK SHANKER ◽  
GERNOT VOGEL

We conducted a molecular phylogenetic study on the Boiga ceylonensis group from the Western Ghats of India, building on a recent morphology-based study. Our analysis supports previous work in elucidating the phylogenetic position of B. nuchalis and B. beddomei s. str. (of Matheran, Western Ghats) as clustering closely with B. ceylonensis, while B. flaviviridis clustered with the Sri Lankan taxon close to B. ranawanei. Additionally, our phylogenetic study revealed the presence of an undescribed taxon in the Southern Western Ghats, more closely related to B. ceylonensis than to any other sampled taxon, including sympatric congeners. This new taxon is described here as a new species Boiga whitakeri sp. nov. from the Devar Malai–Anaimalai hill complex. Based on molecular and morphometric studies, we expand the description of the recently described B. thackerayi as inhabiting almost the entire stretch of the Western Ghats. We also complement the diagnoses of B. nuchalis and B. flaviviridis, and determine the phylogenetic position of B. thackerayi with molecular data. 


2020 ◽  
Author(s):  
Chen Shao ◽  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Khaled A.S. Al-Rasheid ◽  
...  

Abstract Background: Ciliated species, unicellular eukaryotes, are extremely diverse and occupy a very broad spectrum of ecological niches. Even though there is a growing recognition that enormous ciliates associates with key ecosystem processes in different niches, their diversity is not well understood. One reason is that ciliates are very tiny and may often be overlooked in routine biodiversity survey. Furthermore, the morphological and genetic diversity of ciliates per se is vast and dwarfs that among other multicellular eukaryotes. Here, we present the study of a new stichotrichid ciliate, Parasincirra sinica n. g., n. sp. based on classical living morphology, infraciliature, ontogenesis analyses and a comprehensive phylogenetic study, and enhance understanding of ciliates diversity in sludge soil.Results: This new, monotypic genus is defined by having a bipartite adoral zone of membranelles, three frontal cirri, an amphisiellid median cirral row about as long as, or slightly longer than, the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal cirrus and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) five frontoventral-transverse cirral anlagen (excluding undulating membranes anlage) are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellida. The morphological/ morphogenetical differences between the new genus/species and Uroleptoides/ Parabistichella, as well as other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra.


Palaeobotany ◽  
2014 ◽  
Vol 5 ◽  
pp. 73-93 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov

The Gedan floristic assemblage occurs from upper layers of the Kholchan Formation of the Okchotsk-Chukotka volcanogenic belt (OCVB). The locality is situated at the Gedan River in the middle part of the Arman River basin. The Gedan assemblage is composed of 6 taxa: Cladophlebis sp., Sphenobaiera sp., Ginkgo ex gr. adiantoides (Ung.) Heer, Taxodium amguemensis (Efimova) Golovn., Metasequoia sp., Pagiophyllum sp. The similarity of the Gedan floristic assemblage with the Karamken and the Khirumki floristic assemblages from the Kholchan Formation of the Okhotsk sector of the OCVB allows us to join them in the Kholchan flora. This flora is distinct from more ancient Arman flora, which dated as the Turonian-Coniacian and from younger Ola flora, which dated as the Santonian-early Campanian. The age of the Kholchan flora is estimated as the Coniacian on the basis of stratigraphic position, presence of Podozamites, Metasequoia and Quereuxia and also isotopic data. This flora is equivalent with the Chaun flora of Central Chukotka, with the Aleeki flora from the Villigha and Toomahni Rivers interfluve and with the Ulya flora from the southern part of the Okhotsk-Chukotka volcanogenic belt.


Zootaxa ◽  
2021 ◽  
Vol 4958 (1) ◽  
pp. 489-502
Author(s):  
FILIPE MICHELS BIANCHI

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided. 


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2502 ◽  
Author(s):  
Walter G. Joyce ◽  
Tyler R. Lyson ◽  
James I. Kirkland

BackgroundBothremydidae is a clade of extinct pleurodiran turtles known from the Cretaceous to Paleogene of Africa, Europe, India, Madagascar, and North and South America. The group is most diverse during the Late Cretaceous to Paleogene of Africa. Little is known, however, about the early evolution of the group.MethodsWe here figure and describe a fossil turtle from early Late Cretaceous deposits exposed at MacFarlane Mine in Cedar Canyon, southwestern Utah, USA. The sediments associated with the new turtle are utilized to infer its stratigraphic provenience and the depositional settings in which it was deposited. The fossil is compared to previously described fossil pleurodires, integrated into a modified phylogenetic analysis of pelomedusoid turtles, and the biogeography of bothremydid turtles is reassessed. In light of the novel phylogenetic hypotheses, six previously established taxon names are converted to phylogenetically defined clade names to aid communication.ResultsThe new fossil turtle can be inferred with confidence to have originated from a brackish water facies within the late Cenomanian Culver Coal Zone of the Naturita Formation. The fossil can be distinguished from all other previously described pleurodires and is therefore designated as a new taxon,Paiutemys tibertgen. et. sp. nov. Phylogenetic analysis places the new taxon as sister to the EuropeanPolysternon provinciale,Foxemys trabantiandFoxemys mechinorumat the base of Bothremydinae. Biogeographic analysis suggests that bothremydids originated as continental turtles in Gondwana, but that bothremydines adapted to near-shore marine conditions and therefore should be seen as having a circum-Atlantic distribution.


Author(s):  
Nikolay G. ZVERKOV ◽  
Dmitry V. GRIGORIEV ◽  
Andrzej S. WOLNIEWICZ ◽  
Alexey G. KONSTANTINOV ◽  
Evgeny S. SOBOLEV

ABSTRACT The first ichthyosaurian specimens discovered from the Upper Triassic of the Russian Arctic (Kotelny Island, New Siberian Islands) are described herein. They include the remains of large- to small-bodied ichthyosaurians originating from six stratigraphic levels spanning the lower Carnian to middle Norian. The material is mostly represented by isolated vertebrae and ribs, which are not possible to accurately diagnose, but also includes specimens comprising associated vertebrae and a fragmentary skeleton that preserves cranial remains (parabasisphenoid, fragmentary quadrate, partial mandible and hyoids). Based on vertebral and rib morphology, we identify the specimens as representatives of the following taxonomic groups: large-bodied shastasaurids, medium-sized indeterminate ichthyosaurians with a single rib facet in the presacral centra, and small euichthyosaurians with double rib facets present throughout the presacral vertebrae that likely represent toretocnemids and/or basal parvipelvians. In addition, the cranial and mandibular remains preserved in one of the specimens, ZIN PH 5/250, were studied using micro-computed tomography. Its mandible is highly similar to that of toretocnemids, whereas the parabasisphenoid demonstrates a peculiar combination of both plesiomorphic and derived character states, providing the first detailed data on this cranial element in a Late Triassic ichthyosaurian. Furthermore, the specimen also demonstrates a distinctive condition of rib articulation in the anteriormost presacral (cervical) vertebrae, which together with other features allows for the erection of a new taxon – Auroroborealia incognita gen. et sp. nov. Although the phylogenetic position of this taxon is uncertain due to its fragmentary nature, its anatomy, indicating toretocnemid or parvipelvian affinities, further supports the previously hypothesised sister-group relationships between these two clades. The morphology of the parabasisphenoid and vertebral column of the new taxon is discussed in broader contexts of the patterns of evolution of these skeletal regions in ichthyosaurs.


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