The skull of a relative of the stem-group bird Mononykus

  title={The skull of a relative of the stem-group bird Mononykus},
  author={Luis Mar{\'i}a Chiappe and Mark A. Norell and James M. Clark},
In joint expeditions, researchers from the American Museum of Natural History and the Mongolian Academy of Sciences have recovered over 20 alvarezsaurid (Theropoda: Aves) specimens in the Late Cretaceous beds of Mongolia's Gobi Desert. Here we describe a new taxon that is closely related to Mononykus,. This new taxon is represented by two exquisitely preserved skulls — the first known for Alvarezsauridae — details of which support the theory that the group is related to birds,. This theory was… 

A tamerican museum

Comparisons with adult troodontids demonstrate that many characters historically considered important for phylogenetic and taxonomic assessments of adult maniraptorans are present at a relatively early stage of ontogeny.

A Large Bird from the Early Cretaceous of China: New Information on the Skull of Enantiornithines

The histological characterization of CNUVB-0903 indicates that it was not yet a full-grown individual at the time of death, and supports previous evidence indicating that early in their history, enantiornithines were able to achieve relatively large sizes.

Morphological Diversity and Evolution of the Jugal in Dinosaurs

The conspicuous jugal ornaments seen in many ornithischian dinosaurs, like the less striking ones documented in some saurischians, may have played an important role in the social behavior of the species that possessed them, adding to the evidence that agonistic behavior was likely widespread among Ornithischians in particular.

A New Skull of Gobipteryx minuta (Aves: Enantiornithes) from the Cretaceous of the Gobi Desert

The new skull from Ukhaa Tolgod and the reinterpretation of cranial aspects of the previously published material of Gobipteryx minuta and Nanantius valifanovi permit an accurate reconstruction of the palate of this enantiornithine bird, thus adding significant data for understanding the poorly known palatal structure of Mesozoic birds.

The Skull and Head Muscles of Archosauria

This chapter’s goal is to provide a review ofarchosaur anatomy and to give at least some sense of the similarities and differences between archosaur musculature.

Fossil that fills a critical gap in avian evolution

The new taxon, Apsaravis ukhaana, is the best-preserved specimen of a Mesozoic ornithurine bird discovered in over a century and provides data important for assessing morphological evolution across Avialae, with implications for the monophyly of Enantiornithes and Sauriurae.

Cranial Osteology of the Theropod Dinosaur Incisivosaurus gauthieri (Theropoda: Oviraptorosauria)

The holotype skull of the unusual oviraptorosaur Incisivosaurus gauthieri is provided, which indicates that although the incisiform teeth of I. g authieri are morphologically distinct they are replaced in typical archosaurian fashion.

A re-appraisal of Parvicursor remotus from the Late Cretaceous of Mongolia: implications for the phylogeny and taxonomy of alvarezsaurid theropod dinosaurs

The transversely compressed sacral centrum with a sharp ventral keel is the last sacral, not the first sacral as originally alleged, and the two successive sister taxa for Parvicursor are Ceratonykus and Linhenykus.

A Review of Dromaeosaurid Systematics and Paravian Phylogeny

This study provides the most detailed and comprehensive phylogenetic analysis of paravians to date in order to explore the phylogenetic history of dromaeosaurid taxa and reviews and revises the membership of DromaeOSauridae and provides an apomorphy-based diagnosis for all valid taxa.

New Material and Diagnosis of a New Taxon of Alvarezsaurid (Dinosauria, Theropoda) from the Upper Cretaceous Bissekty Formation of Uzbekistan

Dzharaonyx is the most plesiomorphic and geologically oldest member of Parvicursorinae known to date and found within Parvic cursorinae in a polytomy with other Asiatic taxa.



Extraordinary preservation in a new vertebrate assemblage from the Late Cretaceous of Mongolia

WE report here a new locality, Ukhaa Tolgod ('brown hills'), from the Upper Cretaceous of the Gobi Desert of Mongolia, which shows an unmatched abundance of well preserved vertebrate fossils,

Cranial morphology of Archaeopteryx: evidence from the seventh skeleton

The avian features of the skull demonstrate that Archaeopteryx is a bird rather than a feathered nonavian archosaur.

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.

Flightless bird from the Cretaceous of Mongolia

Several features suggest that Mononychus olecranus is more closely related to modern birds than is Archaeopteryx lithographica, and suggests that the early radiation of avialians is only beginning to be sampled.

Anatomy of Patagonykus puertai (Theropoda, Avialae, Alvarezsauridae), from the Late Cretaceous of Patagonia

ABSTRACT The fragmentary skeleton of a new Late Cretaceous avialan theropod from Patagonia is described. Patagonykus puertai possesses caudal trunk vertebrae that are slightly convex caudally. The

Cranial kinesis in the late Cretaceous birds Hesperornis and Parahesperornis

-A recently discovered skull of the Cretaceous toothed diving bird Hesperornis permits evaluation of previous descriptions of the skull, analysis of cranial kinesis in hesperornithid birds, and

On the Mechanical Implications of the Avian Skull and Their Bearing on the Evolution and Classification of Birds

Preliminary investigations dealing with the relationship existing between the morphology of the bird's skull and its kinetic possibilities, appear to show that the thecodont ancestors of Birds, as

A Nestling Bird from the Lower Cretaceous of Spain: Implications for Avian Skull and Neck Evolution

This fossil was a nestling and suggests that early postnatal developments in the Cretaceous enantiornithine birds and those in their extant counterparts are comparable, and reemphasizes the notion that the early morphological transformations of birds were focused on the flight apparatus.

The origin and evolution of birds

Ornithologist and evolutionary biologist Alan Feduccia, author of "Age of Birds," here draws on fossil evidence and studies of the structure and biochemistry of living birds to present knowledge and data on avian evolution and propose a model of this evolutionary process.

A unique multitoothed ornithomimosaur dinosaur from the Lower Cretaceous of Spain

A new specimen, the first ornithomimosaur theropod found in Europe, is reported, which suggests an alternative evolutionary process towards the toothless condition in Ornithomi-mosauria, which could be explained by an exaptation.