The smallest known non-avian theropod dinosaur

  title={The smallest known non-avian theropod dinosaur},
  author={Xing Xu and Zhonghe Zhou and Xiaolin Wang},
Non-avian dinosaurs are mostly medium to large-sized animals, and to date all known mature specimens are larger than the most primitive bird, Archaeopteryx. Here we report on a new dromaeosaurid dinosaur, Microraptor zhaoianus gen. et sp. nov., from the Early Cretaceous Jiufotang Formation of Liaoning, China. This is the first mature non-avian dinosaur to be found that is smaller than Archaeopteryx, and it eliminates the size disparity between the earliest birds and their closest non-avian… 

A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin

Recent fossil discoveries have substantially reduced the morphological gap between non-avian and avian dinosaurs, yet avians including Archaeopteryx differ from non-avian theropods in their limb

Largest bird from the Early Cretaceous and its implications for the earliest avian ecological diversification

A new bird from the Early Cretaceous feathered-dinosaur-bearing continental deposits of Liaoning, northeast China is reported, which is not only larger than Archaeopteryx but is nearly twice as large as the basal dromaeosaur Microraptor.

A new tiny dromaeosaurid dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and niche differentiation among the Jehol dromaeosaurids

The Early Cretaceous Jehol dromaeosaurids are taxonomically and morphologically diverse, and one of them, Microraptor zhaoianus, has been suggested to be among the smallest known non-avialan

A microraptorine (Dinosauria–Dromaeosauridae) from the Late Cretaceous of North America

  • N. LongrichP. Currie
  • Environmental Science, Geography
    Proceedings of the National Academy of Sciences
  • 2009
Hesperonychus is the youngest known member of this lineage, extending the temporal range of the clade by 45 million years, and it is the first microraptorine known from North America, providing further evidence for an affinity between the dinosaur faunas of North America and Asia.

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The lacustrine deposits of the Yixian and Jiufotang Formations in the Early Cretaceous Jehol Group in the western Liaoning area of northeast China are well known for preserving feathered dinosaurs,

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There is no evidence for a major or mass extinction of birds at the end of the Cretaceous, nor for a sudden ‘bottleneck’ in diversity that fostered the early Tertiary origination of living bird ‘Orders’.

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The new discovery amplifies the range of morphological disparity among unenlagiines, demonstrating that by the end of the Cretaceous this clade included large, short-armed forms alongside crow-sized, long-armed, possibly flying representatives.

Description and ontogenetic assessment of a new Jehol microraptorine

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A new microraptorine theropod from the Jehol Biota and growth in early dromaeosaurids

Comparison of histology in the new taxon and Sinornithosaurus indicates that macroscopic signs of maturity developed after the first year, but before cessation of growth, demonstrating that nonhistological indicators of adulthood may be misleading when applied to dromaeosaurids.



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Phylogenetic analysis indicates that, among known theropods with integumentary filaments or feathers, Dromaeosauridae is the most bird-like, and is more closely related to birds than is Troodontidae.

The phylogenetic position of the Tyrannosauridae: implications for theropod systematics

  • T. Holtz
  • Environmental Science, Geography
    Journal of Paleontology
  • 1994
The inclusion of the Tyrannosauridae within Maniraptora suggests a major adaptive radiation of coelurosaurs within Cretaceous Asiamerica comparable to contemporaneous radiations in various herbivorous dinosaurian clades.

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This new taxon from the Yixian Formation provides fresh evidence that therizinosauroids are nested within the coelurosaurian theropods, and supports the hypothesis that the filamentous integumentary structures may be homologous to the feathers of birds.

New information on the anatomy and relationships of Dromaeosaurus albertensis (Dinosauria: Theropoda)

Repreparation and restudy of the holotype of Dromaeosaurus albertensis has produced new anatomical information useful for evaluating the relationships of dromaeosaurids.

The theropod ancestry of birds: new evidence from the late cretaceous of madagascar

Rahona has a robust, hyperextendible second digit on the hind foot that terminates in a sicklelike claw, a unique characteristic of the theropod groups Troodontidae and Dromaeosauridae.

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

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

Anatomy and phylogenetic relationships of the theropod dinosaur Microvenator celer from the Lower Cretaceous of Montana. American Museum novitates ; no. 3240

Reexamination of the holotype revealed the presence of several autapomorphies that provide the basis for a revised diagnosis of Microvenator celer, the earliest known oviraptorosaurian or ovarian theropod represented by diagnostic skeletal remains.

The evolution of dinosaurs.

  • P. Sereno
  • Environmental Science, Geography
  • 1999
The ascendancy of dinosaurs on land near the close of the Triassic now appears to have been as accidental and opportunistic as their demise and replacement by therian mammals at the end of the

Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia)

A critical examination of all jaws and teeth attributed to Troodon, Stenonychosaurus, and Pectinodon concluded that Troodon is the senior synonym of these genera, and that the name Troodontidae has priority over Saurornithoididae.

The earliest known tyrannosaur from the Lower Cretaceous of Thailand

A newly discovered incomplete skeleton of a large theropod from the Early Cretaceous Sao Khua Formation of northeastern Thailand is described as an early and primitive representative of the Tyrannosauridae, suggesting that the early evolution of tyrannosaurids may have taken place in Asia.