Sinornithosaurus by Jim Robins

Feathered dinosaurs are regarded by many paleontologists as transitional fossils between birds and dinosaurs (see Dinosaur-bird connection). It was already well known that ancient birds such as Archaeopteryx had many saurian characteristics, such as claws on their 'fingers' and teeth. For many years it had been theorized that birds evolved from theropod dinosaurs. In the late 1990s, discoveries of feathered dinosaurs provided conclusive evidence of the connection, though the genealogical details are still incomplete. Sinornithosaurus by Jim Robins Used with permission See http://palaeo. ... Sinornithosaurus by Jim Robins Used with permission See http://palaeo. ... Binomial name Sinornithosaurus millenii Xu, Wang and Wu, 1999 Sinornithosaurus millenii (Chinese lizard-bird of the new millennium) is a feathered dromaeosaurid dinosaur species from the Lower Cretaceous (Middle Barremian) of the Yixian Formation in China. ... Paleontology or palaeontology (see Spelling differences) is the study of the history and development of life on Earth, including that of ancient plants and animals, based on the fossil record (evidence of their prehistoric existence as typically preserved in sedimentary rocks). ... A transitional fossil is the fossil remains of a creature that exhibits primitive traits in comparison with the more derived life-forms it is related to. ... Orders Many - see section below. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... The current scientific consensus holds that birds evolved from theropod dinosaurs. ... Binomial name Archaeopteryx lithographica Meyer, 1861 Synonyms see text Archaeopteryx (pronounced )(Greek archaio = ancient + pteryx = wing)), from the Late Jurassic of Germany, is the earliest and most primitive known bird. ... Families See text Theropods (beast foot) are a group of bipedal, primarily carnivorous dinosaurs, belonging to the saurischian (lizard-hip) family. ... See also 1990s, the band The 1990s decade refers to the years from 1990 to 1999, inclusive, sometimes informally including popular culture from the late 1980s and shortly after the year 2000. ... Two feathers Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. ...

Early theories

Shortly after the 1859 publication of Charles Darwin's The Origin of Species, British biologist and evolution-defender Thomas Henry Huxley proposed that birds were descendants of dinosaurs. He cited skeletal similarities, particularly among some saurischian dinosaurs, fossils of the 'first bird' Archaeopteryx and modern birds. In 1868 he published On the Animals which are Most Nearly Intermediate between Birds and Reptiles, making the case. The leading dinosaur expert of the time, Richard Owen, disagreed, claiming Archaeopteryx as the first bird outside dinosaur lineage. For the next century, claims that birds were dinosaur descendants faded, with more popular bird-ancestry hypotheses including 'crocodylomorph' and 'thecodont"'ancestors, rather than dinosaurs or other archosaurs. Charles Robert Darwin FRS (12 February 1809 – 19 April 1882) was an English naturalist who achieved lasting fame by producing considerable evidence that species originated through evolutionary change, at the same time proposing the scientific theory that natural selection is the mechanism by which such change occurs. ... The title page of the 1859 edition of On the Origin of Species. ... A biologist is a scientist devoted to and producing results in biology through the study of organisms. ... In 1832, while travelling on the Voyage of the Beagle, naturalist Charles Darwin collected giant fossils in South America. ... Thomas Huxley Thomas Henry Huxley F.R.S. (May 4, 1825 – June 29, 1895) was a British biologist, known as Darwins Bulldog for his defence of Charles Darwins theory of evolution. ... Groups Sauropodomorpha    Saturnalia    Prosauropoda    Sauropoda Theropoda    Eoraptor    Herrerasauridae    Ceratosauria    Tetanurae       Aves(extant) Saurischians (from the Greek Saurischia meaning lizard hip) are one of the two orders/branches of dinosaurs. ... Binomial name Archaeopteryx lithographica Meyer, 1861 Synonyms see text Archaeopteryx (pronounced )(Greek archaio = ancient + pteryx = wing)), from the Late Jurassic of Germany, is the earliest and most primitive known bird. ... 1868 (MDCCCLXVIII) was a leap year starting on Wednesday (see link for calendar) of the Gregorian calendar or a leap year starting on Friday of the 12-day-slower Julian calendar. ... Sir Richard Owen KCB (July 20, 1804–December 18, 1892) was an English biologist, comparative anatomist and palaeontologist. ... Thecodont (socket-toothed reptile), is a catch-all (paraphyletic) group, now considered an obsolete term, that was formerly used to describe a group of the earliest archosaurs that lived during the Permian and Triassic periods. ... Groups Pterosauria Crocodylia (crocodiles) Dinosauria    Aves (birds) Archosaurs (Greek for ruling reptiles) are a group of diapsid reptiles that first appeared during the late Permian (roughly 250 million years ago). ...

Then, in 1964, John Ostrom discovered a fossilized dinosaur he called Deinonychus antirrhopus, a theropod whose skeletal resemblance to birds seemed unmistakable. Ostrom has since become a leading proponent of the theory that birds are direct descendants of dinosaurs. Further comparisons of bird and dinosaur skeletons, as well as cladistic analysis strengthened the case for the link, particularly for a branch of theropods called maniraptors. Skeletal similarities include the neck, the pubis, the wrists (semi-lunate carpal), the 'arms' and pectoral girdle, the shoulder blade, the clavicle and the breast bone. In all, over a hundred distinct anatomical features are shared by birds and theropod dinosaurs. 1964 (MCMLXIV) was a leap year starting on Wednesday (the link is to a full 1964 calendar). ... John Ostrom John H. Ostrom (February 18, 1928 – July 16, 2005) was an American paleontologist who revolutionized modern understanding of dinosaurs in the 1960s, when he demonstrated that dinosaurs are more like big non-flying birds than they are like lizards (or saurians), an idea first proposed by Thomas Henry... Binomial name Deinonychus antirrhopus Ostrom, 1969 Deinonychus (IPA ) meaning terrible claw (Greek δεινος meaning terrible and ονυξ/ονυχος meaning claw) was a jaguar-sized, carnivorous dromaeosaurid dinosaur species from the Early Cretaceous Period. ... Families See text Theropods (beast foot) are a group of bipedal, primarily carnivorous dinosaurs, belonging to the saurischian (lizard-hip) family. ... This cladogram shows the relationship among various insect groups. ... Maniraptora is a group used in biological classification to cover the birds and the dinosaurs that were related to them. ... The neck is the part of the body on many limbed vertebrates that distinguishes the head from the torso or trunk. ... A man and a woman in the Pioneer plaque. ... In human anatomy, the wrist is the flexible and narrower connection between the forearm and the hand. ... In human anatomy, the carpal bones are the bones of the human wrist. ... In anatomy, an arm is one of the upper limbs of a two-legged animal. ... The pectoral girdle is a set of bones that support the front legs in vertebrates. ... In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone). ... Collarbone and collar bone redirect here. ... Sternum or breastbone is a long, flat bone located in the center of the thorax (chest). ...

By the 1990s, most paleontologists considered birds to be surviving dinosaurs and referred to 'non-avian dinosaurs' (those that went extinct), to distinguish them from birds (aves or avian dinosaurs). Some dinosaur restorations began to picture dinosaurs with a downy or feathery cover. For other meanings of bird, see bird (disambiguation). ...

Direct evidence to support the theory was missing, however. Some mainstream ornithologists including Smithsonian Institute curator Storrs L. Olson, disputed the links, citing the lack of fossil evidence for feathered dinosaurs. The Smithsonian castle, as seen through the garden gate. ...

Fossil evidence

After a century of hypotheses without hard evidence, beautifully preserved (and legitimate) fossils of feathered dinosaurs were discovered, during the 1990s and 2000s. The fossils were preserved in a Lagerstätte — a sedimentary deposit exhibiting remarkable richness and completeness in its fossils — in Liaoning, China. The area had repeatedly been smothered in volcanic ash produced by eruptions in Inner Mongolia, 124 million years ago, during the Early Cretaceous Period. The fine-grained ash preserved the living organisms, that it buried, in extraordinary detail. The area was teeming with life, with millions of leaves, the oldest known angiosperms, insects, fish, frogs, salamanders, mammals, turtles, lizards and crocodilians having been discovered, to date. See also 1990s, the band The 1990s decade refers to the years from 1990 to 1999, inclusive, sometimes informally including popular culture from the late 1980s and shortly after the year 2000. ... This article or section does not cite its references or sources. ... Lagerstätten (German; singular Lagerstätte; literally place of storage, resting place) are sedimentary deposits that exhibit extraordinary fossil richness or completeness. ... Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ... Liaoning (Simplified Chinese: 辽宁; Traditional Chinese: 遼寧; pinyin: ) is a northeastern province of the Peoples Republic of China. ... Inner Mongolia (Mongolian: ᠥᠪᠦᠷ ᠮᠣᠨᠺᠤᠯᠤᠨ ᠥᠪᠡᠷᠲᠡᠺᠡᠨ ᠵᠠᠰᠠᠬᠤ ᠣᠷᠤᠨ r Mongghul-un bertegen Jasaqu Orun; Chinese: 内蒙古自治区; Hanyu Pinyin: N... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... A geologic period is a subdivision of geologic time that divides Eras into smaller timeframes. ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also angiosperms or Magnoliophyta) are one of the major groups of modern plants, comprising those that produce seeds in specialized reproductive organs called flowers, where the ovulary or carpel is enclosed. ... Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ... The Guppy (Poecilia reticulata) is one of the most popular freshwater aquarium fish species in the world. ... Distribution of frogs (in black) Suborders Archaeobatrachia Mesobatrachia Neobatrachia - List of Anuran families The frog is an amphibian in the order Anura (meaning tail-less from Greek an-, without + oura, tail). ... Suborders Cryptobranchoidea Salamandroidea Sirenoidea Salamander is the common name applied to approximately 500 amphibians with slender bodies, short legs, and long tails. ... Orders Multituberculata (extinct) Palaeoryctoides (extinct) Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Cingulata Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Leptictida (extinct) Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata... Suborders Cryptodira Pleurodira See text for families. ... Families Many, see text. ... Suborders Eusuchia Protosuchia † Mesosuchia † Sebecosuchia † Thalattosuchia † Crocodilia is an order of large reptiles that appeared about 220 million years ago. ...

The most important discoveries at Liaoning have been a host of spectacular feathered dinosaur fossils, with a steady stream of new finds filling in the picture of the dinosaur-bird connection and adding more to theories of the evolutionary development of feathers and flight.

Genuine feathers?

There had been claims that the supposed feathers of the Chinese fossils were a preservation artifact. Actually they have roughly the same appearance as those of birds fossilized in the same locality, so there is no serious reason to think they are of different nature; moreover, no non-theropod fossil from the same site shows such an artifact, but sometimes show unambiguous hair (some mammals) or scales (some reptiles).

The Archaeoraptor fake

In 1999 a supposed 'missing link' fossil of an apparently feathered dinosaur named "Archaeoraptor liaoningensis", found in Liaoning Province, northeastern China, turned out to be a fake, composed of two portions of different animals. The bottom portion is from a dromaeosaurid now known as Microraptor and the upper portion from a primitive bird now known as Yanornis (formerly Archaeovolans). Archaeoraptor was a fossil believed to be an intermediary between dinosaurs and birds, but proved to be an archaeological forgery. ... 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Old Farts by the Sometimes-United Nations. ... Archaeoraptor was a fossil believed to be an intermediary between dinosaurs and birds, but proved to be an archaeological forgery. ... Liaoning (Simplified Chinese: 辽宁; Traditional Chinese: 遼寧; pinyin: Liáoníng) is a northeastern province of the Peoples Republic of China. ... Microraptor was a small, bird-like dinosaur related to the dromaeosaurs. ... Yanornis was an early Cretaceous bird, thought to be closely related to the common ancestor of all birds. ... Yanornis was an early Cretaceous bird, thought to be closely related to the common ancestor of all birds. ...

This fake fossil, of course, does not discard the numerous other, valid feathered dinosaur fossils; in fact, the initial mistaken identity and its eventual resolution provides firm evidence that both avian and non-avian dinosaurs with feathers existed during the Cretaceous.

Current knowledge

List of dinosaur genera preserved with feathers

A number of non-avian dinosaurs are now known to have been feathered. Direct evidence of feathers exists for the following genera (listed in order of publication):

1. Sinosauropteryx (1996)
2. Shuvuuia (1998)
3. Sinornithosaurus (1999)
4. Beipiaosaurus (1999)
5. Microraptor (2000)
6. Epidendrosaurus (2002)
7. Cryptovolans (2002)
8. Scansoriopteryx (2002)
9. Yixianosaurus (2003)
10. Dilong (2004)
11. Pedopenna (2005)

Some other fossils show evidence of true feathers. Although they are usually classified as non-avian dinosaurs, they have many characterisics of true birds, and are probably related to them. Binomial name Sinosauropteryx prima Ji Q. & Ji S., 1996 Sinosauropteryx prima (first Chinese lizard-feather) was the first non-avian dinosaur found with the fossilized impressions of feathers. ... Binomial name Shuvuuia deserti Shuvuuia deserti is a 3-foot carnivorous feathered dinosaur which belongs to the family Alvarezsauridae. ... Binomial name Sinornithosaurus millenii Xu, Wang and Wu, 1999 Sinornithosaurus millenii (Chinese lizard-bird of the new millennium) is a feathered dromaeosaurid dinosaur species from the Lower Cretaceous (Middle Barremian) of the Yixian Formation in China. ... Binomial name Beipiaosaurus inexpectus Xu, Tang & Wang, 1999 Beipiaosaurus inexpectus is a therizinosauroid, a member of a bizarre group of theropod dinosaurs. ... Microraptor was a small, bird-like dinosaur related to the dromaeosaurs. ... Binomial name Epidendrosaurus ningchengensis Zhang et. ... Cryptovolans pauli is a 90 cm long feathered dromaeosaurid dinosaur recently discovered in the Jiufotang site, China. ... Binomial name Epidendrosaurus ningchengensis Zhang et. ... Binomial name Yixianosaurus longimanus Xu and Wang, 2003 Yixianosaurus longimanus (long-handed Yixian lizard) was a maniraptoran dinosaur from the Early Cretaceous of China. ... Dilong paradoxus was an ancestor of Tyrannosaurus rex and had a covering of feathers. ... Pedopenna daohugouensis (Xu & Zhang 2005) was a small eumaniraptoran dinosaur from the Late Jurassic from the Daohugou beds in China. ...

1. Protarchaeopteryx (1997)
2. Caudipteryx (1998)
3. Jinfengopteryx (2005)

Protarchaeopteryx robustus is a turkey-sized feathered dinosaur from China. ... Caudipteryx was a genus of small, peacock-sized Early Cretaceous theropods (members of Theropoda, the group of typically carnivorous dinosaurs that lived about 125 million years ago). ... Binomial name Jinfengopteryx elegans Ji et. ...

Primitive feather types

At present, the most primitive (known) feathered dinosaur is Sinosauropteryx (Jurassic/Cretaceous, 150-120 mya), whose body was covered with feather-like structures that look like hollow tubes, or hairs. They may or may not have had barbs, like downy (plumulaceous) feathers. Another early fossil, Dilong paradoxus (Early Cretaceous), an ancestor of Tyrannosaurus rex, also had similar feather structures. These early fossils suggest that feathers originally developed as insulators, to maintain body temperatures (thus also providing evidence for warm-blooded dinosaurs). Flight would have been a later evolutionary adaptation (or exaptation) of feathers. Binomial name Sinosauropteryx prima Ji Q. & Ji S., 1996 Sinosauropteryx prima (first Chinese lizard-feather) was the first non-avian dinosaur found with the fossilized impressions of feathers. ... Mya has more than one meaning: Mya, an American R&B singer mya (unit), an abbreviation for million years ago, used as a unit of time in astronomy and geology mya, the ISO 639 alpha-3 code for the Burmese language General Bo Mya, Chief Commander of the Karen National... Dilong paradoxus was an ancestor of Tyrannosaurus rex and had a covering of feathers. ... Binomial name Tyrannosaurus rex Osborn, 1905 Tyrannosaurus rex (ty-RAN-o-sawr-us) meaning king tyrant lizard because of its size and large teeth and claws (Greek tyrannos = tyrant + sauros = lizard; Latin rex = king), also known colloquially as T. rex and The King of the Dinosaurs, was a giant carnivorous... // Definition An Insulator is a material or object which resists the flow of electric charge. ... A warm-blooded (homeothermic) animal is one that can keep its core body temperature at a nearly constant level regardless of the temperature of the surrounding environment (that is, to maintain thermal homeostasis) . This can involve not only the ability to generate heat, but also the ability to cool down... An exaptation is a biological adaptation where the biological function currently performed by the adaptation was not the function performed while the adaptation evolved under earlier pressures of natural selection. ...

A model of Microraptor at the American Museum of Natural History

The first dinosaur fossils from the region found to have true flight-structured feathers (pennaceous feathers) were Protarchaeopteryx and Caudipteryx (135-121 mya). It is more likely that their feathers were used for display rather than for flight. Image File history File linksMetadata Amnh30. ... Image File history File linksMetadata Amnh30. ... Microraptor was a small, bird-like dinosaur related to the dromaeosaurs. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Pennaceous feathers are also known as contour feathers and are present in most modern birds and in some species of maniraptoran dinosaurs. ... Protarchaeopteryx robustus is a turkey-sized feathered dinosaur from China. ... Caudipteryx was a genus of small, peacock-sized Early Cretaceous theropods (members of Theropoda, the group of typically carnivorous dinosaurs that lived about 125 million years ago). ...

Taxonomy and the inference of feathers in other dinosaurs

Feathered dinosaur fossil finds to date, together with cladistic analysis, suggest that many types of theropod may have had feathers, not just those that are especially similar to birds. In particular, the smaller theropod species may all have had feathers and possibly even the larger theropods (for instance T. rex) may have had feathers, in their early stages of development after hatching. Large adult theropods are unlikely to have had feathers, however, as the need for insulation would be less important, since inertial heat retention would likely be sufficient to manage heat. Retention of internal heat may even have become a problem, had these very large creatures been feathered. This cladogram shows the relationship among various insect groups. ...

Fossil feather impressions are extremely rare therefore only a few feathered dinosaurs have been identified so far. However, through a process called phylogenetic bracketing, scientists can infer the presence of feathers on poorly-preserved specimens. All fossil feather specimens have been found to show certain similarities. Due to these similarities and through developmental research almost all scientists agree that feathers could only have evolved once in dinosaurs. Feathers would then have been passed down to all later, more derived species (although it is possible that some lineages lost feathers secondarily). If a dinosaur falls at a point on an evolutionary tree within the known feather-bearing lineages, scientists assume it too had feathers, unless conflicting evidence is found. This technique can also be used to infer the type of feathers a species may have had, since the developmental history of feathers is now reasonbly well-known (Prum & Brush, 2002).

The evolutionary tree below shows the relationships of the various groups of feathered dinosaurs, noting which species have been discovered with feather impressions and which scientists infer had feathers via 'bracketing'.

 Coelurosauria ├─Tugulusaurus (may or may not have been feathered) │ └───Tyrannosauroidea (primitive feathers) │ ├──?Dilong paradoxus (feather impressions) │ └───Tyrannosaurus (scale impressions, may have lost some feathers) │ ├─Compsognathidae (primitive, two-branched feathers) │ ├─?Sinosauropteryx (feather impressions) │ ├─Juravenator (scale impressions, may have lost some feathers) │ └─Compsognathus (feathers possible) │ └─Maniraptoriformes ├─Ornithomimosauria (feathers likely) ├─Alvarezsauridae (feathers with a central vane) │ └───Shuvuuia (feathers preserved in three dimensions) │ └───Maniraptora (flight feathers and down-like contour feathers) ├─Yixianosaurus (feather impressions) │ ├─Oviraptoriformes (vaned, plumaceous feathers) │ ├─Protarchaeopteryx (feather impressions) │ │ │ ├─Oviraptorosauria │ │ ├─Caudipteryx (feather impressions) │ │ └───Oviraptoridae (feathers extremely likely, skeletal feather adaptations) │ │ │ └─Therizinosauria │ └─Beipiaosaurus (feather impressions) │ └───Paraves (flight feathers and down-like contour feathers) ├─Pedopenna (feather impressions) │ ├─Deinonychosauria (symmetrical pennaceous wing feathers) │ ├─Troodontidae │ │ └─Jinfengopteryx (feather impressions) │ │ │ └─Dromaeosauridae │ ├─Rahonavis (skeletal feather/flight adaptations) │ ├─Cryptovolans (feather impressions) │ ├─Microraptor (feather impressions) │ ├─Sinornithosaurus (feather impressions) │ └───Velociraptor (feathers extremely likely) │ ├─Epidendrosaurus (feather impressions) │ └───Aves (asymmetrical flight feathers) 

Dilong paradoxus was an ancestor of Tyrannosaurus rex and had a covering of feathers. ... Binomial name Sinosauropteryx prima Ji Q. & Ji S., 1996 Sinosauropteryx prima (first Chinese lizard-feather) was the first non-avian dinosaur found with the fossilized impressions of feathers. ... Binomial name Shuvuuia deserti Shuvuuia deserti is a 3-foot carnivorous feathered dinosaur which belongs to the family Alvarezsauridae. ... Binomial name Yixianosaurus longimanus Xu and Wang, 2003 Yixianosaurus longimanus (long-handed Yixian lizard) was a maniraptoran dinosaur from the Early Cretaceous of China. ... Protarchaeopteryx robustus is a turkey-sized feathered dinosaur from China. ... Caudipteryx was a genus of small, peacock-sized Early Cretaceous theropods (members of Theropoda, the group of typically carnivorous dinosaurs that lived about 125 million years ago). ... Binomial name Beipiaosaurus inexpectus Xu, Tang & Wang, 1999 Beipiaosaurus inexpectus is a therizinosauroid, a member of a bizarre group of theropod dinosaurs. ... Pedopenna daohugouensis (Xu & Zhang 2005) was a small eumaniraptoran dinosaur from the Late Jurassic from the Daohugou beds in China. ... Binomial name Jinfengopteryx elegans Ji et. ... Cryptovolans pauli is a 90 cm long feathered dromaeosaurid dinosaur recently discovered in the Jiufotang site, China. ... Microraptor was a small, bird-like dinosaur related to the dromaeosaurs. ... Binomial name Sinornithosaurus millenii Xu, Wang and Wu, 1999 Sinornithosaurus millenii (Chinese lizard-bird of the new millennium) is a feathered dromaeosaurid dinosaur species from the Lower Cretaceous (Middle Barremian) of the Yixian Formation in China. ... Binomial name Velociraptor mongoliensis Osborn, 1924 Synonyms Ovoraptor djadochtari Osborn, 1924 (nomen nudum) Velociraptor (meaning swift thief) is a genus of dromaeosaurid theropod dinosaur that existed approximately 83 to 70 million years ago during the later part of the Cretaceous Period. ... Binomial name Epidendrosaurus ningchengensis Zhang et. ... For other meanings of bird, see bird (disambiguation). ...

References

• Prum, R. & Brush A.H. (2002). "The evolutionary origin and diversification of feathers". The Quarterly Review of Biology 77: 261-295.

See also

• Archaeopteryx
• Bird
• Dinosaur
• Dinosaur-bird connection
• Dromaeosauridae
• Luis Rey

Binomial name Archaeopteryx lithographica Meyer, 1861 Synonyms see text Archaeopteryx (pronounced )(Greek archaio = ancient + pteryx = wing)), from the Late Jurassic of Germany, is the earliest and most primitive known bird. ... Orders Many - see section below. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... The current scientific consensus holds that birds evolved from theropod dinosaurs. ... Genera Achillobator Adasaurus Atrociraptor Bambiraptor Buitreraptor Dromaeosauroides Dromaeosaurus Deinonychus Neuquenraptor Pyroraptor Saurornitholestes Unenlagia Utahraptor Variraptor Velociraptor Dromaeosaurids, raptors or members of the family Dromaeosauridae (running lizards) are theropod dinosaurs. ... Luis V. Rey (b. ...

External links

• Downy Dinos on EvoWiki
• DinoBuzz, dinosaur-bird controversy explained, by UC Berkley.
• Journal of Dinosaur Paleontology, with many articles on dinosaur-bird links.
• Life-like images of feathered dinosaurs