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Saurornithoides Mongoliensis
''Saurornithoides'' ( ) is a genus of troodontid maniraptoran dinosaur, which lived during the Late Cretaceous period. These creatures were predators, which could run fast on their hind legs and had excellent sight and hearing. The name is derived from the Greek stems ''saur~'' (lizard), ''ornith~'' (bird) and ''eides'' (form), referring to its bird-like skull. Description ''Saurornithoides'' is a member of the troodontids, a group of small, bird-like, gracile maniraptorans. All troodontids have many unique features of the skull, such as closely spaced teeth in the lower jaw, and large numbers of teeth. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian encephalization quotients, meaning they were behaviourally advanced and had keen senses. ''Saurornithoides'' was a rather small troodontid. Though a possible adult, the type specimen has a midline skull length of 189 millimetres, compared to 272 millimetres for ''Zanabazar junior'', itself ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maniraptora
Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to ''Ornithomimus velox''. It contains the major subgroups Avialae, Deinonychosauria, Oviraptorosauria and Therizinosauria. '' Ornitholestes'' and the Alvarezsauroidea are also often included. Together with the next closest sister group, the Ornithomimosauria, Maniraptora comprises the more inclusive clade Maniraptoriformes. Maniraptorans first appear in the fossil record during the Jurassic Period (see '' Eshanosaurus''), and survive today as living birds. Description Maniraptorans are characterized by long arms and three-fingered hands (though reduced or fused in some lineages), as well as a "half-moon shaped" (semi-lunate) bone in the wrist (carpus). In 2004, Tom Holtz and Halszka Osmólska pointed out six other maniraptoran characters relating to specific details of the skeleton. Unlike most other saurischian dinosaurs, which h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Ear
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts: * The cochlea, dedicated to hearing; converting sound pressure patterns from the outer ear into electrochemical impulses which are passed on to the brain via the auditory nerve. * The vestibular system, dedicated to balance The inner ear is found in all vertebrates, with substantial variations in form and function. The inner ear is innervated by the eighth cranial nerve in all vertebrates. Structure The labyrinth can be divided by layer or by region. Bony and membranous labyrinths The bony labyrinth, or osseous labyrinth, is the network of passages with bony walls lined with periosteum. The three major parts of the bony labyrinth are the vestib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zanabazar (dinosaur)
''Zanabazar'' (meaning "Zanabazar") is a genus of large troodontid dinosaurs from the Late Cretaceous of Mongolia. The genus was originally named by Rinchen Barsbold as the new species ''Saurornithoides junior''. In 2009 it was reclassified as its own genus and species, ''Zanabazar junior'', named after the first spiritual figurehead of Tibetan buddhism, Zanabazar. The holotype includes a skull, vertebrae, and right hindlimb. ''Zanabazar'' was one of the largest and most derived troodontids. History of discovery The holotype was discovered in 1964 from the Bügiin Tsav locality of the Nemegt Formation and initially described by Rinchen Barsbold as a new species of ''Saurornithoides'' (''S. junior'') in 1974. This specimen, IGM 100/1, includes a nearly complete skull and braincase, part of the pelvis, some tail vertebrae, and parts of the right hindlimb. In 2009 a review of the genus found that the support for ''S. junior'' in the same genus as ''S. mongoliensis'' was lacking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Vertebra
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part of the pelvic cavity, between the two wings of the pelvis. It forms joints with four other bones. The two projections at the sides of the sacrum are called the alae (wings), and articulate with the ilium at the L-shaped sacroiliac joints. The upper part of the sacrum connects with the last lumbar vertebra (L5), and its lower part with the coccyx (tailbone) via the sacral and coccygeal cornua. The sacrum has three different surfaces which are shaped to accommodate surrounding pelvic structures. Overall it is concave (curved upon itself). The base of the sacrum, the broadest and uppermost part, is tilted forward as the sacral promontory internally. The central part is curved outward toward the posterior, allowing greater room for the pelv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinusonasus
''Sinusonasus'' is a genus of dinosaurs from the Early Cretaceous Period, recovered from the Yixian Formation. It lived in what is now the Liaoning Province of China. ''Sinusonasus'' was a theropod, specifically a troodontid dinosaur. The type species, ''Sinusonasus magnodens'', was named and described by Xu Xing and Wang Xiaolin in 2004.Xu X. and Wang X.-l. 2004. "A New Troodontid (Theropoda: Troodontidae) from the Lower Cretaceous Yixian Formation of Western Liaoning, China". ''Acta Geologica Sinica'' 78(1): 22-26 The generic name, derived from Latin ''sinus'', "wave", and ''nasus'', "nose", refers to the sinusoid form, in lateral view, of the nasals. The specific name means "big-toothed" from Latin ''magnus'', "large" and ''dens'', "tooth". In a later publication the species is referred to as "Sinucerasaurus" but this is a junior objective synonym. The holotype, IVPP V 11527, was found in the Lujiatun Member of the Yixian Formation, dating from the Hauterivian. It consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinornithoides
''Sinornithoides'' (meaning "Chinese bird form") is a genus of troodontid theropod dinosaurs containing the single species ''Sinornithoides youngi''. ''S. youngi'' lived during the Early Cretaceous ( Aptian/Albian stage, around 113 million years ago).Sereno, P.C. (2010). "Taxonomy, cranial morphology, and relationships of parrot-beaked dinosaurs (Ceratopsia: ''Psittacosaurus'')." ''New Perspectives on Horned Dinosaurs''. Bloomington: Indiana, 21-58. It measured approximately one meter long (3.3 ft). It lived in Inner Mongolia, China, and probably ate invertebrates and other small prey. They lived in what is now Mongolia, which was part of Laurasia. Discovery In 1988, a Chinese-Canadian expedition discovered the remains of a small theropod near Huamuxiao, in the Ordos Basin of Inner Mongolia. ''Sinornithoides youngi'', the type species, was named and described in 1993/1994 by Dale Russell and Dong Zhiming based on this fossil specimen from the Lower Cretaceous Ejinhoro Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Tree
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobi Desert
The Gobi Desert (Chinese: 戈壁 (沙漠), Mongolian: Говь (ᠭᠣᠪᠢ)) () is a large desert or brushland region in East Asia, and is the sixth largest desert in the world. Geography The Gobi measures from southwest to northeast and from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°–89° east). In 2007, it occupied an arc of land in area. In its broadest definition, the Gobi includes the long stretch of desert extending from the foot of the Pamirs (77° east) to the Greater Khingan Mountains, 116–118° east, on the border of Manchuria; and from the foothills of the Altay, Sayan, and Yablonoi mountain ranges on the north to the Kunlun, Altyn-Tagh, and Qilian mountain ranges, which form the northern edges of the Tibetan Plateau, on the south. A relatively large area on the east side of the Greater Khingan range, between the upper waters of the Songhua (Sungari) and the upper waters of the Liao-h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalization Quotient
Encephalization quotient (EQ), encephalization level (EL), or just encephalization is a relative brain size measure that is defined as the ratio between observed to predicted brain mass for an animal of a given size, based on nonlinear regression on a range of reference species. It has been used as a proxy for intelligence and thus as a possible way of comparing the intelligences of different species. For this purpose it is a more refined measurement than the raw brain-to-body mass ratio, as it takes into account allometric effects. Expressed as a formula, the relationship has been developed for mammals and may not yield relevant results when applied outside this group. Perspective on intelligence measures Encephalization quotient was developed in an attempt to provide a way of correlating an animal's physical characteristics with perceived intelligence. It improved on the previous attempt, brain-to-body mass ratio, so it has persisted. Subsequent work, notably Roth, found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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