jedzenie: Origin of birds

Evidence: 100 • authority: 72

The scientific question of which larger group of animals birds evolved within has traditionally been called the "origin of birds". The present scientific consensus is that birds are a group of maniraptoran theropod dinosaurs that originated during the Mesozoic era. A close relationship between birds and dinosaurs was first proposed in the nineteenth century after the discovery of the primitive bird Archaeopteryx in Germany. Birds and extinct non-avian dinosaurs share many unique skeletal traits. Moreover, fossils of more than thirty species of non-avian dinosaur with preserved feathers have been collected. There are even very small dinosaurs, such as Microraptor and Anchiornis, which have l…

Evidence: 45 • authority: 88

Trophic shift and the origin of birds. Abstract Birds are characterized by evolutionary specializations of both locomotion (e.g., flapping flight) and digestive system (toothless, crop, and gizzard), while the potential selection pressures responsible for these evolutionary specializations remain unclear. Here we used a recently developed molecular phyloecological method to reconstruct the diets of the ancestral archosaur and of the common ancestor of living birds (CALB). Our results showed that the ancestral archosaur exhibited a predominant Darwinian selection of protein and fat digestion and absorption, whereas the CALB showed a marked enhanced selection of carbohydrate and fat digestion…

Evidence: 39 • authority: 88

Evolutionary Origin of Nocturnality in Birds. Abstract The diel activity patterns of living animals are observable, whereas knowing about those patterns in ancestral or extinct animals remains a challenge. Differences in the diel activity patterns of animals may have led to morphological and genetic differences in their visual systems. Recent developments in reconstructing the traits of ancestral animals offer the opportunity to improve our knowledge of the diel activity patterns of ancestral animals. One of the most important findings is the nocturnality of the common ancestors of living birds. Accumulating evidence based on morphological, behavioural and molecular data suggest the potenti…

Evidence: 39 • authority: 72

John Alan Feduccia (born April 25, 1943) is a paleornithologist specializing in the origins and phylogeny of birds. He is S. K. Heninger Distinguished Professor Emeritus at the University of North Carolina. Feduccia's authored works include three major books, The Age of Birds, The Origin and Evolution of Birds, and Riddle of the Feathered Dragons. Feduccia opposes the scientific consensus that birds originated from and are deeply nested within Theropoda, and are therefore living theropod dinosaurs. He has argued for an alternative theory in which birds share a common stem-ancestor with theropod dinosaurs among more basal archosaurian lineages, with birds originating from small arboreal arch…

Evidence: 34 • authority: 80

Birds' evolutionary origin and diversification occurred earlier in the Jurassic Period than previously believed

Evidence: — • authority: 72

Avialae ("bird wings") is a clade of archosaurian vertebrates containing the only living branch of dinosaurs, the birds (class Aves), and their closest relatives. It is usually defined as all theropod dinosaurs more closely related to birds than to deinonychosaurs, though alternative definitions are occasionally used (see below). Archaeopteryx lithographica, from the late Jurassic Period Solnhofen Formation of Germany, is usually considered the earliest known avialan which may have had the capability of powered flight; a minority of studies have suggested that it might have been a deinonychosaur instead. Several older (but non flight-capable) possible avialans are known from the late Jurass…

Evidence: — • authority: 72

A feathered dinosaur is any species of dinosaur possessing feathers, including all species of birds. In recent decades, evidence has accumulated that many non-avian dinosaur species also possessed feathers or feather-like structures in some shape or form. The extent to which feathers or feather-like structures were present in dinosaurs as a whole is a subject of ongoing debate and research. It has been suggested that feathers had originally functioned as thermal insulation, as it remains their function in the down feathers of infant birds prior to their eventual modification in birds into structures that support flight. Since scientific research began on dinosaurs in the early 1800s, they w…

Evidence: — • authority: 72

Archosauria or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only known extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many Mesozoic marine reptiles. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians…

Evidence: — • authority: 72

Dinosaurs are a diverse group of reptiles that first appeared during the Triassic period, between 243 and 233.23 million years ago. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 million years ago, and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record demonstrates that birds are modern feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic. Birds were therefore the only dinosaur lineage to survive the Cretaceous–Paleogene extinction event approximately 66 million years ago, and constitute the only known living dinosaurs. This list of dinosaurs is a comprehensive listin…

Evidence: — • authority: 72

The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. Birds are categorized as a biological class, Aves. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird. Modern phylogenies place birds in the dinosaur clade Theropoda. According to the current consensus, Aves and a sister group, the order Crocodilia, together are the sole living members of an unranked reptile clade, the Archosauria. Four distinct lineages of bird survived the Cretaceous–Paleogene extinction event 66 million years ago, giving rise to ostri…

Evidence: — • authority: 72

Dinosaurs are a diverse group of warmblooded reptiles of the clade Dinosauria. They existed through most of the Mesozoic era, first appearing early in the Triassic period. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosa…

Evidence: — • authority: 88

Archosaurian reptiles with Gondwanan affinities in the Upper Cretaceous of Europe. ABSTRACT The Late Cretaceous (mainly Campanian and Maastrichtian) non‐marine vertebrate faunas of Europe contain archosaurian reptiles which belong to groups otherwise known mainly or only from the southern ('Gondwanan') continents. They include titanosaurid sauropods, abelisaurid theropods, and trematochampsid crocodilians. The occurrence of these forms together with others of ‘Asiamerican’ affinities gives the Late Cretaceous vertebrate faunas of Europe a peculiar composition, which makes them clearly different from the well‐known faunas from western North America and Central Asia. The Gondwanan dinosaurs a…