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

1993 ◽  
Vol 30 (10) ◽  
pp. 2128-2138 ◽  
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.

A nearly complete skeleton of a new troodontid dinosaur from the Early Cretaceous of the Ordos Basin, Inner Mongolia, People's Republic of China

1993 ◽  
Vol 30 (10) ◽  
pp. 2163-2173 ◽  
Author(s):  
Dale A. Russell ◽  
Zhi-Ming Dong
Keyword(s):  
Early Cretaceous ◽  
Inner Mongolia ◽  
Hind Limb ◽  
New Genus ◽  
Ordos Basin ◽  
New Genus And Species ◽  
Republic Of China ◽  
Vertebral Count ◽  
The Ordos Basin ◽  
Orbital Rim

An articulated skeleton of a 1 m long theropod from Early Cretaceous strata in Inner Mongolia is clearly referrable to the Troodontidae, representing the most complete specimen known of this group of small carnivorous dinosaurs. The tail and neck of the animal were curled next to its body upon burial; the upper surface of the skeleton was badly damaged by erosion. Previously unknown details of troodont morphology include a quadratic contact with the braincase wall (forming part of a channel leading to the lateral depression), a presacral vertebral count possibly similar to that of most theropods, absence of ossified caudal tendons, presence of a rod-like clavicle, and absence of sternal ossifications. A new genus and species (Sinornithoides youngi n.gen., n.sp.) is established for the specimen on the basis of its short skull, laterally directed orbital rim of the frontal, and elongated hind limb. A reassessment of character distributions in other small theropods and primitive birds must be completed before troodontid affinities can be established with greater precision.

A Lower Cretaceous enantiornithine bird from the Ordos Basin of Inner Mongolia, People's Republic of China

1993 ◽  
Vol 30 (10) ◽  
pp. 2177-2179 ◽  
Author(s):  
Zhi-Ming Dong
Keyword(s):  
Early Cretaceous ◽  
Lower Cretaceous ◽  
Inner Mongolia ◽  
Ordos Basin ◽  
People’S Republic Of China ◽  
People's Republic Of China ◽  
Republic Of China ◽  
The Ordos Basin

The discovery of an Early Cretaceous bird from the Ordos Basin of Inner Mongolia (People's Republic of China) is reported. The specimen, collected by the Dinosaur Project (China – Canada – Alberta – Ex Terra) Expedition of 1990, includes scapulocoracoids, humeri, radii, ulnae and metacarpals. It is referred to the Enantiornithes.

New material of Ikechosaurus sunailinae (Reptilia: Choristodira) from the Early Cretaceous Laohongdong Formation, Ordos Basin, Inner Mongolia, and the interrelationships of the genus

1993 ◽  
Vol 30 (10) ◽  
pp. 2153-2162 ◽  
Author(s):  
Donald B. Brinkman ◽  
Zhi-Ming Dong
Keyword(s):  
Early Cretaceous ◽  
Inner Mongolia ◽  
Ordos Basin ◽  
Temporal Region ◽  
Republic Of China ◽  
Skull Roof ◽  
Anterior Position ◽  
Anterior Extension ◽  
New Material ◽  
The Ordos Basin

New material of Ikechosaurus sunailinae from the Early Cretaceous Laohongdong Formation of the Ordos Basin, Inner Mongolia, People's Republic of China, is described. This material, which includes well-preserved articulated skeletons and a series of isolated elements, demonstrates that Ikechosaurus is more closely related to Champsosaurus than to Simoedosaurus, sharing with Champsosaurus the presence of an elongate snout, anteriorly constricted parasphenoid with the foramen canalis caroticus internus located in or near the suture between the parasphenoid and the pterygoid, an anterior extension of the anterior end of the jugal, and an elongate symphysis including the splenial. Ikechosaurus is primitive relative to Champsosaurus in the anterior position of the internal narial openings, in the less strongly flared temporal region with the temporal openings placed largely above one another, in the absence of fenestra in the occiput between the parietal and squamosal, and in the interpterygoid vacuity bordered posteriorly by the basisphenoid. Ikechosaurus and Tchoiria are at a similar grade of evolution, but can be separated by details in the arrangement of bone forming the skull roof.

New material of Sinemys (Testudines, Sinemydidae) from the Early Cretaceous of China

1993 ◽  
Vol 30 (10) ◽  
pp. 2139-2152 ◽  
Author(s):  
Donald B. Brinkman ◽  
Jiang-Hua Peng
Keyword(s):  
Early Cretaceous ◽  
Inner Mongolia ◽  
Ordos Basin ◽  
Sensu Stricto ◽  
Posterior Lobe ◽  
Lateral Expansion ◽  
New Material ◽  
The Ordos Basin ◽  
Hydrodynamic Function ◽  
A New Species

Sinemys lens is redescribed on the basis of new material from the Early Cretaceous of Shandong, China, and a new species of Sinemys from the Ordos Basin in Inner Mongolia is recognized. Sinemys and Manchurochelys are placed in the Sinemydidae (sensu stricto) on the basis of the derived features of a small first suprapygal and an elongate, narrow posterior lobe of the plastron. Sinemys is autapomorphic in the absence of a cervical scute, the entry of the first vertebral onto the anterior margin of the carapace, the absence of a pygal bone, the entry of the fifth vertebral scute into the posterior margin of the carapace, in that the riblike lateral projections of the last three costal bones fit between the adjacent peripherals, and in the isolation of the epiplastra from the hyoplastra by lateral expansion of the entoplastron.Sinemys gamera sp.nov., from the Early Cretaceous Luohandong Formation of the Ordos Basin, Inner Mongolia, is characterized by the presence of a flat carapace with an abbreviated posterior end and the presence of long spines on the seventh costal. The spines in S. gamera may serve a hydrodynamic function.

A microsaur from the Mississippian of illinois and a standard format for morphological characters

1999 ◽  
Vol 73 (5) ◽  
pp. 908-923 ◽  
Author(s):  
R. Eric Lombard ◽  
John R. Bolt
Keyword(s):  
Vertebral Column ◽  
Sister Group ◽  
Morphological Characters ◽  
Occipital Condyle ◽  
Sister Group Relationship ◽  
Neural Arch ◽  
Standard Format ◽  
Caudal Vertebrae ◽  
Early Tetrapods ◽  
Occipital Condyles

The oldest known microsaur is preserved in a nodule from the Kinkaid Formation (Mississippian; Elvirian) collected near Goreville, Illinois. At least eight individuals are represented: three by partial skulls plus vertebral column segments with associated limb elements, and five by postcrania only. Skulls are crushed, incomplete, and exposed mainly in palatal view. Palatal bones are denticulate and the palatine has in addition a single large tooth. The basipterygoid process is laterally directed and the basipterygoid joint is open. The atlas carries large articulating facets for proatlantes, a pair of which are identifiable in one specimen. These features have not been found previously in a microsaur. All vertebral segments are dominated by a biconcave pleurocentrum; sutures between the pleurocentrum and neural arch are visible in presacral vertebrae. Distinctive microsaurian intercentra occur between all presacral pleurocentra. Their presence reinforces the hypothesis that microsaur intercentra are homologous with those of other early tetrapods. Caudal vertebrae retain separate haemal arches and some have ribs.Observed microsaur synapomorphies include: atlas with large median odontoid; atlas with concave lateral facets for occipital condyle; paired occipital condyles that are broad and concave; and thin, straplike intercentra. No observed features support a sister-group relationship with any other microsaur species, or placement within any higher level microsaur group. Because significant portions of the skeleton are missing or inaccessible, the Goreville microsaur is not formally named. A standardized, hierarchical format for skeletal characters is introduced that facilitates data sharing and comparison and fosters rapid archiving and retrieval.

First record of Eretmophyllum (Ginkgoales) with well-preserved cuticle from the Middle Jurassic of the Ordos Basin, Inner Mongolia, China

Palaeoworld ◽  
2018 ◽  
Vol 27 (2) ◽  
pp. 188-201 ◽  
Author(s):  
Yun-Feng Li ◽  
Chun-Lin Sun ◽  
Hongshan Wang ◽  
David L. Dilcher ◽  
Xiao Tan ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Inner Mongolia ◽  
Ordos Basin ◽  
First Record ◽  
The Ordos Basin
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