Branched integumental structures in Sinornithosaurus and the origin of feathers

  title={Branched integumental structures in Sinornithosaurus and the origin of feathers},
  author={Xing Xu and Zhonghua Zhou and Richard O. Prum},
The evolutionary origin of feathers has long been obscured because no morphological antecedents were known to the earliest, structurally modern feathers of Archaeopteryx. It has been proposed that the filamentous integumental appendages on several theropod dinosaurs are primitive feathers; but the homology between these filamentous structures and feathers has been disputed, and two taxa with true feathers (Caudipteryx and Protarchaeopteryx) have been proposed to be flightless birds… 

The dorsal appendages of the Triassic reptile Longisquama insignis: reconsideration of a controversial integument type

The existing feather similarity is explained by their development from a filamentous primordium and a complex sequence of individual processes, some of which are reminiscent of processes observed in feather development.

Filamentous Integuments in Nonavialan Theropods and Their Kin: Advances and Future Perspectives for Understanding the Evolution of Feathers

F fossil specimens will continue to provide key data for the reconstruction and documentation of the evolutionary history of feathers, including evolutionary experiments and forms that no longer occur in nature.

Origin of archosaurian integumentary appendages: the bristles of the wild turkey beard express feather-type beta keratins.

The discovery that structurally unique "filamentous integumentary appendages" are associated with several different non-avian dinosaurs continues to stimulate the development of models to explain the

Feather Evolution in Pennaraptora

The origin and early evolution of complex feathers and flight abilities in paravian theropods were not linear processes, but more complex than previously thought.


Five major morphogenesis events are inferred to have occurred sequentially early in feather evolution before the origin of the Aves, and the function of the first feather is inferred to be neither related to flight nor to insulation.

Evolution of birds: ichthyosaur integumental fibers conform to dromaeosaur protofeathers

The overall findings of the study are that the thesis of dinosaur "protofeathers" requires more substantial support than exists at present.

Additional information on the primitive contour and wing feathering of paravian dinosaurs

Comparing a range of dinosaur taxa with preserved integumentary appendages using high-resolution photographs to better understand fossil feather morphology and gain insight into their function and evolution suggests that differentiated barbicels are relatively derived compared to pennaceous feathers and the appearance of wings.

S06-2 Origin and early evolution of feathers: evidence from the Early Cretaceous of China

It is postulate that protofeathers evolved through a stage when they were used for balance both in trunk-climbing, and in jumping and gliding between tree branches, and if the homology of integumentary appendages in non-theropod archosaurs to feathers is established, then the most primitive feathers might have a much earlier origin and wider distribution than is thought today.

A new Chinese specimen indicates that ‘protofeathers’ in the Early Cretaceous theropod dinosaur Sinosauropteryx are degraded collagen fibres

A new specimen of Sinosauropteryx is reported which shows that the integumental structures proposed as protofeathers are the remains of structural fibres that provide toughness.

The evolution of the feather: Sinosauropteryx, life, death and preservation of an alleged feathered dinosaur

The signs point strongly to invertebrate colonization of the carcass of Sinosauropteryx rather than vertebrate predation or scavenging, with moderate decay associated with the purge fluids while major decay was forestalled by burial, at most a few days after death.



A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China

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.

A therizinosauroid dinosaur with integumentary structures from China

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.

The smallest known non-avian theropod dinosaur

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 theropod relatives.

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.

Nonavian feathers in a late Triassic archosaur.

It is suggested that Longisquama's elongate integumentary appendages are probably homologous with avian feathers and antedate the feathers of Archaeopteryx, the first known bird from the Late Jurassic.

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.

Walker's mammals of the world

From aardwolves and bandicoots to yapoks and zorillas, Ernest P. Walker's Mammals of the World is the most comprehensive-the pre-eminent-reference work on mammals. Now, completely revised and

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

Two feathered dinosaurs from northeastern China

Two theropods from the Upper Jurassic/Lower Cretaceous Chaomidianzi Formation of Liaoning province, China are described, which represent stages in the evolution of birds from feathered, ground-living, bipedal dinosaurs.

Cursoriality in bipedal archosaurs

Surprisingly, Caudipteryx, described as a theropod dinosaur, possessed an anterior centre of mass and hindlimb proportions resembling those of cursorial birds, which may have implications for interpreting the locomotory status of its ancestors.