A Small-Bodied Troodontid (Dinosauria, Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China

AbstractA new small-bodied troodontid (LH PV39) recovered from the Upper Cretaceous Wulansuhai Formation, Suhongtu, Inner Mongolia, China, is described. The new specimen preserves six postaxial cervical vertebrae, five completely fused sacral and four posterior caudal vertebrae in addition to two manual unguals. The completely fused neurocentral junctions indicate that a skeletally mature individual of the same species of LH PV39 would be smaller than Philovenator and comparable in body size to a skeletal mature individual of Almas. The extremely dorsoventrally compressed sacral centra and neural canal, and the middle three sacral centra that are shorter and wider than the first and the last one distinguishing LH PV39 from other known troodontids. A series of phylogenetic analyses were conducted using modified published matrices. By coding LH PV39 in different strategies, the troodontid affinity of LH PV39 is confirmed and it was recovered as the sister taxon of either Mei and Sinovenator (LH PV39 scored as a separate OTU) or Linhevenator (incorporating LH PV39 into Philovenator) in the best resolved coelurosaurian interrelationships. The referral of LH PV39 to Philovenator does not seriously alter the phylogenetic position of Philovenator nor the interrelationships of troodontids. This new finding confirms that the small and large sized troodontids are coexisted in the Gobi Desert of the Mongolia Plateau until the end of Cretaceous.

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Ordosemys leios, n.gen., n.sp., a new turtle from the Early Cretaceous of the Ordos Basin, Inner Mongolia

Canadian Journal of Earth Sciences ◽

10.1139/e93-184 ◽

1993 ◽

Vol 30 (10) ◽

pp. 2128-2138 ◽

Cited By ~ 50

Author(s):

Donald B. Brinkman ◽

Jiang-Hua Peng

Keyword(s):

Early Cretaceous ◽

Inner Mongolia ◽

Cervical Vertebrae ◽

Ordos Basin ◽

Sister Group ◽

Sister Group Relationship ◽

Articular Surfaces ◽

Caudal Vertebrae ◽

The Ordos Basin

Ordosemys leios, n.gen., n.sp., from the Early Cretaceous Luohandong Formation, Zhidan Group, Ordos Basin, Inner Mongolia, is a primitive aquatic turtle with a reduced, fenestrated plastron. It shares with the members of the Centrocryptodira the presence of well-formed articular surfaces on the cervical and caudal vertebrae. Within the Centrocryptodira, characters of the cervical vertebrae suggest it is more closely related to the Polycryptodira than is the Meiolaniidae. Ordosemys shares with the Chelydridae the presence of two procoelous anterior caudals, but this character may be primitive for the Polycryptodira. Characters of the basicranial region of the braincase shared by Ordosemys and the Chelonioidea support a sister-group relationship between these two taxa, but a sister-group relationship between Ordosemys and the Polycryptodira is more strongly supported by characters shared by the Chelonioidea and other members of the Polycryptodira.

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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

Canadian Journal of Earth Sciences ◽

10.1139/e96-042 ◽

1996 ◽

Vol 33 (4) ◽

pp. 541-577 ◽

Cited By ~ 47

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.

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Crocodyliform affinities for Kemkemia auditorei Cau & Maganuco, 2009 from the Late Cretaceous of Morocco

Natural History Sciences ◽

10.4081/nhs.2012.119 ◽

2012 ◽

Vol 153 (1) ◽

pp. 119 ◽

Cited By ~ 1

Author(s):

Gabriel Lio ◽

Federico Agnolin ◽

Andrea Cau ◽

Simone Maganuco

Keyword(s):

Upper Cretaceous ◽

New Genus ◽

Phylogenetic Position ◽

Caudal Vertebra ◽

New Genus And Species ◽

Theropod Dinosaur ◽

Incertae Sedis ◽

Theropod Dinosaurs ◽

Neural Canal ◽

Posterolateral Margin

Kemkemia auditorei Cau & Maganuco, 2009 was recently described as a new genus and species of theropod dinosaur on the basis on an isolated distal caudal vertebra. The holotype and only known specimen comes from Kem Kem beds (Upper Cretaceous) of Morocco. In the present paper we review the phylogenetic position of Kemkemia and we conclude that this taxon belongs to Crocodyliformes. It shares with crocodyliforms the presence of a concavity at the posterolateral margin of neural spines, an inflated neural canal, and reduced prezygapophyses, among other traits. This combination of characters clearly distinguishes Kemkemia from theropod dinosaurs. In this way, Kemkemia is here considered as a Crocodyliformes incertae sedis, and based on the absence of unique characters, the genus and species Kemkemia auditorei is proposed as a nomen dubium.

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The oldest and first nearly complete skeleton of a chelid, of the Hydromedusa sub-group (Chelidae, Pleurodira), from the Upper Cretaceous of Patagonia

BSGF - Earth Sciences Bulletin ◽

10.2113/172.2.237 ◽

2001 ◽

Vol 172 (2) ◽

pp. 237-244 ◽

Cited By ~ 35

Author(s):

Marcelo de la Fuente ◽

France de Lapparent de Broin ◽

Teresa Manera de Bianco

Keyword(s):

Upper Cretaceous ◽

Cervical Vertebrae ◽

Lake Area ◽

Lower Eocene ◽

Rio Negro ◽

Caudal Vertebrae ◽

The Family ◽

Lower Maastrichtian ◽

Middle Member ◽

Upper Campanian

Abstract A new pleurodiran (side necked) turtle is described on material from the Upper Cretaceous of Patagonia, from sediments outcropping at Cerro Blanco, Yaminue Creek, Rio Negro, Argentina. The sediments are compared to those from the Pellegrini lake area referred to the middle Member of the Allen Formation, Upper Campanian-Lower Maastrichtian. Yaminuechelys gasparinii n.g., n.sp., is a pleurodiran turtle on the pelvis sutured to the shell and a chelid on the formula of cervical vertebrae and the lateral cheek emargination, deeply extended towards (as here) or up to the posterior emargination. It is the oldest record of a nearly complete skeleton of a chelid, long necked (elongated cervical vertebrae, lowered skull), and the first sufficiently known of the Chelodina-Hydromedusa group (elongated skull, lowered neural arch and centrum of the cervicals, low zygapophyses processes, strong polygoned decoration) and of the Hydromedusa sub-group (widened inner nares by reduced palatine ossification). The carapace is 41,8 cm long. It is more primitive than Hydromedusa (Eocene-Extant, South America) and retains primitive characters either still present or no more present in the other chelids of the Pseudemydura, Emydura and Phrynops groups (short necked) and Chelus group (long necked), representing the anterior clades of phyletic diversification [Gaffney, 1977], or evolutive grades, of the family. Such are plesiomorphic, relative to Hydromedusa, the less pronounced lateral skull emargination, wider and longer hyoid elements, wider nucal and cervical, this not drawn back, presence of lateral mesoplastra, not shortened bridge, straight borders of the not shortened and not widened posterior plastral lobe, amphicoelous sacrals and caudal vertebrae uniting amphicoelous, concavoplaty--(i.e. anteriorly concave, posteriorly flat) and procoelous or weakly procoelous elements. As Hydromedusa, Yaminuechelys n. g. retains primitive characters such as the long series of neurals, the very lateral attachment of the axillar and inguinal processes and the attachment of the pelvis, below pleural 8 (and 7 in the extant form) and a small part of the suprapygal, and the ischitatic sutures prolonged on the xiphiplastral points. It is distinguished by the apomorphic presence of a wide and week anterior carapacial notch. Yaminuechelys n.g., or aff. Yaminuechelys spp. are known in Patagonia by fragmentary remains in a dozen of Upper Cretaceous and two Palaeocene localities. Before them, chelids are known in the world only by undefined smaller forms from Lower Albian and Upper Albian-Cenomanian Patagonian localities. In Australia, they are known from Palaeocene-Lower Eocene (no Cretaceous data before) with already extant Australian diversified forms. Yaminuechelys n.g. demonstrates how long the diversification in chelids is realized in South Gondwana before the full break of the continents.

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A new large Pliosaurid from the Barremian (Lower Cretaceous) of Sáchica, Boyacá, Colombia

Earth Sciences Research Journal ◽

10.15446/esrj.v22n4.69916 ◽

2018 ◽

Vol 22 (4) ◽

pp. 223-238 ◽

Cited By ~ 8

Author(s):

María Eurídice Páramo-Fonseca ◽

Cristian David Benavides-Cabra ◽

Ingry Esmirna Gutiérrez

Keyword(s):

Lower Cretaceous ◽

New Genus ◽

Cervical Vertebrae ◽

Cladistic Analysis ◽

Morphological Characteristics ◽

Phylogenetic Position ◽

New Genus And Species ◽

Mandibular Symphysis ◽

Caudal Vertebrae ◽

Mandibular Teeth

A new fossil MP111209-1 found in the Barremian beds of Sáchica, a town near Villa de Leiva representing the more complete skeleton found in the region is described here. After a detailed study of its morphological characteristics, it is evident that the new specimen represents a new genus and species of brachauchenine pliosaurid from Central Colombia that we named Sachicasaurus vitae gen. et sp. nov. Sachicasaurus is a large brachauchenine (almost 10 m in length) characterized by the following combination of characters: skull exceeding two meters in length, transverse constriction in the rostrum, caniniform teeth present, pineal foramen in a very advanced position, palatines separated in the midline by the pterygoids, very short mandibular symphysis (bearing four teeth positions), reduced number of mandibular teeth (less than 20), slender hyoid bones, 12 cervical vertebrae, cervical centra showing ventral foramina, single rib facet in all cervical centra, at least 40 pre-caudal vertebrae, and ilium with a long posterior projection. Although it is difficult to clearly establish the phylogenetic position of Sachicasaurus viate within Brachaucheninae due to its combination of primitive and derived features, the morphological comparisons and the cladistic analysis show an evident phylogenetic proximity of Sachicasaurus to the Aptian-Albian genus Kronosaurus.

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The taxonomy of a new parvicursorine alvarezsauroid specimen IVPP V20341 (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China

10.7287/peerj.preprints.702 ◽

2014 ◽

Author(s):

Michael Pittman ◽

Xing Xu ◽

Josef B. Stiegler

Keyword(s):

Inner Mongolia ◽

Upper Cretaceous ◽

Current Knowledge ◽

Anatomical Features ◽

Caudal Vertebrae

A new parvicursorine alvarezsauroid theropod specimen IVPP V20341 from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China is described. IVPP V20341 appears to be distinguishable amongst alvarezsauroids by cervical proceoly and relatively larger semi-circular neural canals, but these features are not proposed as autapomorphies because current knowledge of alvarezsauroid necks and tails remains sparse. IVPP V20341 is distinguishable from Linhenykus - the sole parvicursorine at Bayan Mandahu - by 13 anatomical features that mostly relate to cervical and caudal vertebrae. However, it is unclear how these vertebral elements compare positionally along the spine, so more complete future finds could revise the observed differences. Thus, there are still seven parvicursorine species from the Cretaceous Gobi Basin after the discovery of IVPP V20341.

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The taxonomy of a new parvicursorine alvarezsauroid specimen IVPP V20341 (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China

10.7287/peerj.preprints.702v1 ◽

2014 ◽

Author(s):

Michael Pittman ◽

Xing Xu ◽

Josef B. Stiegler

Keyword(s):

Inner Mongolia ◽

Upper Cretaceous ◽

Current Knowledge ◽

Anatomical Features ◽

Caudal Vertebrae

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The Complete DNA Sequence of the Mitochondrial Genome of a “Living Fossil,” the Coelacanth (Latimeria chalumnae)

Genetics ◽

10.1093/genetics/146.3.995 ◽

1997 ◽

Vol 146 (3) ◽

pp. 995-1010 ◽

Cited By ~ 1

Author(s):

Rafael Zardoya ◽

Axel Meyer

Keyword(s):

Mitochondrial Genome ◽

Tandem Repeats ◽

Phylogenetic Analyses ◽

Large Data ◽

Molecular Data ◽

Phylogenetic Position ◽

Data Set ◽

Living Fossil ◽

Latimeria Chalumnae ◽

Relationship Of

The complete nucleotide sequence of the 16,407-bp mitochondrial genome of the coelacanth (Latimeria chalumnae) was determined. The coelacanth mitochondrial genome order is identical to the consensus vertebrate gene order which is also found in all ray-finned fishes, the lungfish, and most tetrapods. Base composition and codon usage also conform to typical vertebrate patterns. The entire mitochondrial genome was PCR-amplified with 24 sets of primers that are expected to amplify homologous regions in other related vertebrate species. Analyses of the control region of the coelacanth mitochondrial genome revealed the existence of four 22-bp tandem repeats close to its 3′ end. The phylogenetic analyses of a large data set combining genes coding for rRNAs, tRNA, and proteins (16,140 characters) confirmed the phylogenetic position of the coelacanth as a lobe-finned fish; it is more closely related to tetrapods than to ray-finned fishes. However, different phylogenetic methods applied to this largest available molecular data set were unable to resolve unambiguously the relationship of the coelacanth to the two other groups of extant lobe-finned fishes, the lungfishes and the tetrapods. Maximum parsimony favored a lungfish/coelacanth or a lungfish/tetrapod sistergroup relationship depending on which transversion:transition weighting is assumed. Neighbor-joining and maximum likelihood supported a lungfish/tetrapod sistergroup relationship.

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Resolving Phylogenetic Relationships within Passeriformes Based on Mitochondrial Genes and Inferring the Evolution of Their Mitogenomes in Terms of Duplications

Genome Biology and Evolution ◽

10.1093/gbe/evz209 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2824-2849 ◽

Cited By ~ 6

Author(s):

Paweł Mackiewicz ◽

Adam Dawid Urantówka ◽

Aleksandra Kroczak ◽

Dorota Mackiewicz

Keyword(s):

Phylogenetic Analyses ◽

Mitochondrial Genes ◽

The Other ◽

Phylogenetic Position ◽

Evolutionary Relationships ◽

Mitochondrial Genomes ◽

Ancestral State ◽

Phylogenetic Information ◽

Long Time ◽

Tree Topologies

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.

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Nephromyces represents a diverse and novel lineage of the Apicomplexa that has retained apicoplasts

Genome Biology and Evolution ◽

10.1093/gbe/evz155 ◽

2019 ◽

Cited By ~ 4

Author(s):

Sergio A Muñoz-Gómez ◽

Keira Durnin ◽

Laura Eme ◽

Christopher Paight ◽

Christopher E Lane ◽

...

Keyword(s):

Life Style ◽

Metabolic Pathways ◽

Evolutionary History ◽

Phylogenetic Analyses ◽

Phylogenetic Position ◽

Biosynthetic Pathways ◽

History Of ◽

Sea Squirts ◽

Shed Light ◽

Apicoplast Genome

Abstract A most interesting exception within the parasitic Apicomplexa is Nephromyces, an extracellular, probably mutualistic, endosymbiont found living inside molgulid ascidian tunicates (i.e., sea squirts). Even though Nephromyces is now known to be an apicomplexan, many other questions about its nature remain unanswered. To gain further insights into the biology and evolutionary history of this unusual apicomplexan, we aimed to (1) find the precise phylogenetic position of Nephromyces within the Apicomplexa, (2) search for the apicoplast genome of Nephromyces, and (3) infer the major metabolic pathways in the apicoplast of Nephromyces. To do this, we sequenced a metagenome and a metatranscriptome from the molgulid renal sac, the specialized habitat where Nephromyces thrives. Our phylogenetic analyses of conserved nucleus-encoded genes robustly suggest that Nephromyces is a novel lineage sister to the Hematozoa, which comprises both the Haemosporidia (e.g., Plasmodium) and the Piroplasmida (e.g., Babesia and Theileria). Furthermore, a survey of the renal sac metagenome revealed 13 small contigs that closely resemble the genomes of the non-photosynthetic reduced plastids, or apicoplasts, of other apicomplexans. We show that these apicoplast genomes correspond to a diverse set of most closely related but genetically divergent Nephromyces lineages that co-inhabit a single tunicate host. In addition, the apicoplast of Nephromyces appears to have retained all biosynthetic pathways inferred to have been ancestral to parasitic apicomplexans. Our results shed light on the evolutionary history of the only probably mutualistic apicomplexan known, Nephromyces, and provide context for a better understanding of its life style and intricate symbiosis.

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