New evidence concerning avian origins from the Late Cretaceous of Patagonia

  title={New evidence concerning avian origins from the Late Cretaceous of Patagonia},
  author={Fernando Emilio Novas and Pablo F. Puertat},
The spate of recent discoveries of Mesozoic birds has substantially improved our understanding of the early evolution of birds and flight1–5, but has failed to close the morphological gap between the Upper Jurassic Archaeopteryx lithographica, the earliest known bird, and the Dromaeosauridae, the group of non-avian theropod dinosaurs regarded as most closely related to birds6,7. Here we describe a theropod dinosaur from Patagonia, Unenlagia comahuensis gen. et sp. nov., which partially fills… 
Paravian Phylogeny and the Dinosaur-Bird Transition: An Overview
It is concluded that troodontid affinities of anchiornithines, and dromaeosaurids affinITIES of microraptorians and unenlagiids are dismissed in favor of sister group relationships with Avialae, and main phylogenetic hypotheses that compete some topics about the non-avian dinosaur-bird transition are analyzed.
The available evidence strongly supports the classification of birds within theropods and indicates that many avian attributes previously thought to be unique to birds first evolved among maniraptoran dinosaurs.
The origin and early evolution of birds
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’.
Pre-Archaeopteryx coelurosaurian dinosaurs and their implications for understanding avian origins
Mapping some of the salient features onto a temporally-calibrated theropod phylogeny indicates that characteristics related to flight and arboreality evolved at the base of the Paraves, earlier than the Late Jurassic.
The earliest dromaeosaurid theropod from South America
A near-complete, small dromaeosaurid is described that is both the most complete and the earliest member of the Maniraptora from South America and which provides new evidence for a unique Gondwanan lineage of DromaeOSauridae with an origin predating the separation between northern and southern landmasses.
New theropod dinosaur from the Upper Cretaceous of Patagonia sheds light on the paravian radiation in Gondwana
A new paravian from the Cenomanian-Turonian (Late Cretaceous) of Río Negro province, NW Patagonia, Argentina is found that probably constitutes a previously unknown grade in the avian-line theropods in which some flight-related adaptations of the forelimbs are present in cursorial taxa.
Feathered dinosaurs from China and the evolution of major avian characters.
  • Xing Xu
  • Biology, Medicine
    Integrative zoology
  • 2006
An evolutionary model is proposed here to describe the major stages of feather evolution, a process characterized by a combination of both transformational and innovative modifications.
Non‐avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China
The discovery of four-winged dinosaurs was suggested to provide strong evidence supporting the ‘tree-down’ hypothesis for the origin of avian flight, though in-depth analysis and more data are needed to confirm this.
New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria
Bicentenaria amplifies the array of basal coelurosaurs that inhabited Gondwana during the Cretaceous, also including compsognathids, Aniksosaurus and Santanaraptor, and reveals the importance of the new taxon in the understanding of the early diversification of Coelurosauria.
Juvenile Birds from the Early Cretaceous of China: Implications for Enantiornithine Ontogeny
The skeletal morphology of three nearly complete early juvenile avians from the renowned Early Cretaceous Yixian Formation of Liaoning Province in northeastern China are reported on, suggesting that fledging occurred very early in ontogeny, thus supporting a precocial or highly precocial strategy for enantiornithine hatchlings.


An Early Cretaceous bird from Spain and its implications for the evolution of avian flight
A new, exquisitely preserved, bird from the Lower Cretaceous Konservat-Lagerstätte of Las Hoyas (Cuenca, Spain) which provides evidence for the oldest known alula (bastard wing) and the recognition of a new enantiornithine taxon, Eoalulavishoyasi.
Archaeopteryx and the origin of birds
Analysis of the five presently known skeletal specimens of Archaeopteryx confirm the conclusions (long rejected by most subsequent workers) of Heilmann (1926), Lowe (1935, 1944, 1944) and Holmgren (1955), namely, that the skeletal anatomy of Archaeipteryx is extraordinarily similar to that of contemporaneous and succeeding coelurosaurian dinosaurs.
Archaeopteryx and the Origin of Flight
The primordial insulative function of contour feathers and the predatory hypothesis for the enlargement of the remiges seem to account for the otherwise paradoxical presence in Archaeopteryx on essentially modern "flight" feathers.
New subclass of birds from the Cretaceous of South America
Current classification of birds recognizes three subclasses which are morphologically distinct: the Archaeornithes for Archaeopteryx, the Odontornithes for the Hesperornithiformes and the
Unusual Early Cretaceous birds from Spain
The Neocomian Spanish outcrops of Montsec (province of Lérida) and the new one of Las Hoyas (province of Cuenca) have yielded several avian remains in the last few years. Several isolated feathers
Early Evolution of Avian Flight and Perching: New Evidence from the Lower Cretaceous of China
Modern avian flight function and perching capability must have evolved in small-bodied birds in inland habitats not long after Archaeopteryx.
Odontornithes; a Monograph of the Extinct Toothed Birds of North America
WEST from the valley of the Mississippi the stratified formations which underlie the prairie region spread over thousands of square miles nearly as horizontal as when they were deposited. Here and
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
The first 85 million years of avian evolution
More than half of the evolutionary history of birds is played out in the Mesozoic, and the Phylogenetic structure of this diversity has provided clues for better understanding of the evolution of functional, developmental and physiological characteristics of modern birds.
The Physics of Leaping Animals and the Evolution of Preflight
It is proposed that a running and jumping bipedal animal that used its forelimbs for balance could be the precursor of animals with powered flight, and that gliding animals do not fit a plausible model to explain the evolutionary pathway leading to powered flight.