italictitle speciesbox name Protoavis fossil range Late Triassic Norian br fossil range 210 earliest 216 latest 203 image Protoavis paratype skeletal.png image caption Protoavis texensis paratype TTU P ... Sankar Chatterjee Chatterjee , 1991 in paleontology 1991 genus Protoavis parent authority Chatterjee, 1991 species texensis authority Chatterjee, 1991 Protoavis meaning first bird is a Nomen dubium ... different interpretations of what Protoavis actually is. When it was first described, the fossils ... back Origin of birds avian origins some 60 75 million years. The original describer of Protoavis texensis ... skeletal structure is allegedly more bird like. Protoavis has been reconstructed as a carnivorous ... are actual quill knobs. However, this description of Protoavis assumes that Protoavis has been correctly interpreted as a bird. Almost all palaeontologists doubt that Protoavis is a bird ... Protoavis is usually depicted as being a Bipedalism bipedal archosaur , similar to several poposaurid ... the same time as Protoavis . ref name DMLMartzjeff1 cite mailing list url http dml.cmnh.org 1997Oct msg00571.html title Re Protoavis? date Mon, 20 Oct 1997 accessdate 2009 08 11 mailinglist Dinosaur ... as quill knobs, ref name Chatterjee1995 Chatterjee, S. 1995 The Triassic bird Protoavis . Archaeopteryx ... or not. ref name Ostrom1996 Skull and braincase The Endocast braincase of Protoavis is similar in some ... rp 2244 However, Protoavis is also remarkedly non bird like in that it possess only a single exit for the trigeminal ... Protoavis as a bird. ref name CurrieZhao93 The skull has an extremely narrow parietal bone parietal ... http dml.cmnh.org 2001Apr msg00748.html title Protoavis & Drepanosauridae sensu Renesto, 1999 date ... that portions of Protoavis may be drepanosaurid in nature. ref name DML0748 Chatterjee presents the skull of Protoavis as complete, although only the caudal aspect of the cranium is represented ... synapomorphies for the Endocast braincase of Protoavis including the structure of the otic capsule, the widespread ... more details
Refimprove date April 2009 In paleontology , a chimera is a fossil which was reconstructed with elements coming from more than a single species or genus of animal. A now classic example of chimera is Protoavis . List of paleontological chimeras Brontosaurus Lametasaurus Palaeosaurus Protoavis Ultrasauros Category Paleontology paleo stub es Quimera paleontol gica ko ru sv Chimaira paleontologi tr Kimera paleontoloji ... more details
Unreferenced date December 2009 The term Prehistory prehistoric reptile covers a broad category that is intended to help distinguish the dinosaur s from other prehistoric reptiles. As the dinosaurs, because of their long and successful reign for many millions of years, are almost exclusively dealt with in their own category of prehistoric life . The category covers all the non dinosaurian reptiles which are often erroneously considered to be dinosaur s, such as the sea faring varieties of plesiosaur s and the flying pterosaur s. Also included are ancient crocodile s such as Deinosuchus . For information on the mammal like reptiles mammal like reptiles therapsid s and other amniote s often considered reptiles including the well known Dimetrodon , which are not part of the clade Sauropsid a with which Reptilia is generally synonymized , see Synapsid amniotes related to mammals . For information on the ancestors of reptiles, traditionally classified as labyrinthodont amphibian s, see Reptiliomorpha reptile like tetrapod s . List of prehistoric reptiles by group Early reptile s Silvanerpeton Captorhinidae Captorhinids Protorothyrididae Protorothyridids Hylonomus Early anapsid s Brazilosaurus Elginia Hylonomus Hypsognathus Labidosaurus Mesosaurus Millerettid s Milleretta Pareiasaurus Scutosaurus Bolosaurid s Pareiasaur s Bradysaurus Scutosaurus Anthodon reptile Anthodon Turtle s, tortoise s and terrapin s Archelon Meiolania Palaeotrionyx Proganochelys Pleurosternon Stupendemys Testudo atlas Early diapsid s Araeoscelida ns Petrolacosaurus Spinoaequalis Araeoscelis Avicephala ns Protoavis Longisquama Coelurosauravus Champsosaurus Youngina Thalattosauria ns Askeptosaurus Eosuchia ns Lepidosauria ns Ichthyosaur s Californosaurus Cymbospondylus Shonisaurus Ichthyosaurus Mixosaurus Ophthalmosaurus Temnodontosaurus Eurhinosaurus Plesiosaur s, placodont s, and nothosaur s Ceresiosaurus Claudiosaurus Cryptocleidus Elasmosaurus Henodus Nothosaurus Placodus Placochelys Kronosaurus ... more details
Year nav topic5 1991 paleontology science Year in paleontology header 1991 Mollusca Newly named bivalves class wikitable sortable align center width 100 Name Novelty Status Authors Age Unit Location Notes Images Similodonta wahli ref name Hints2000 cite journal last1 Hints first1 L. last2 Orasp ld first2 A. last3 Kaljo first3 D. year 2000 title Stratotype of the Porkuni Stage with comments on the R a Member Uppermost Ordovician, Estonia journal Proceedings of the Estonian Academy of Sciences, Geology volume 49 issue 3 pages 177 199 url http books.google.com books?hl en&lr &id gEHPcVavLuQC&oi fnd&pg PA177&dq Stratotype of the Porkuni Stage with comments on the R C3 B6a Member uppermost Ordovician, Estonia &ots uBAmIlczAm&sig 2pJWe684ewEuPCPyKfmZW8 DtXM v onepage&q&f false ref and the type species Similodonta similis . ref name Cope1999 cite journal last1 Cope first1 J.C.W. year 1999 title Middle Ordovician bivalves from Mid Wales and the Welsh Borderland journal Palaeontology volume 42 issue 3 pages 467 499 url http onlinelibrary.wiley.com doi 10.1111 1475 4983.00081 pdf doi 10.1111 1475 4983.00081 ref Sp nov Valid Isakar Late Ordovician Arina Formation Flag Estonia Archosauromorphs Sankar Chatterjee s discovery of a possible Triassic bird, Protoavis , if genuine, would push avian origins back almost 70 million years. The find ignites controversy over the connection between dinosaurs and birds. Newly named birds Genera no longer considered to be birds Protoavis . The avian status of Protoavis has since been almost universally rejected by paleontologists. Dinosaurs Newly named dinosaurs Data courtesy of George Olshevsky s dinosaur genera list ref name ddinogeorge cite web last Olshevsky first George title Dinogeorge s Dinosaur Genera List url http www.polychora.com dinolist.html accessdate 2008 08 07 ref and Dr. Jeremy Montague s dinosaur genus database. ref name montaguedatabase cite web last Montague first Jeremy title Dr. Montague s Database url http www.barry.edu ... more details
Infobox person name Sankar Chatterjee image caption birth date birth place death date death place other names known for Study of prehistoric vertebrates occupation paleontology paleontologist nationality Sankar Chatterjee is a paleontology paleontologist , and is the Paul W. Horn Professor of Earth science Geosciences at Texas Tech University and Curator of Paleontology at the Museum of Texas Tech University . ref http www.depts.ttu.edu communications vistas archive 04 winter stories young investigators.php Texas Tech University Young Investigators ref He earned his Doctor of Philosophy Ph. D. from the University of Calcutta in 1970 and was a Post doctoral Fellow at the Smithsonian Institution from 1977 1978. ref http www.gesc.ttu.edu Fac pages chatterjee Sankar Chatterjee ref Dr. Chatterjee s has focused on the origin, evolution, functional anatomy, and systematics of Mesozoic vertebrates, including Basal phylogenetics basal archosaur s, dinosaur s, pterosaur s, and bird s. ref http www.tshaonline.org handbook online articles VV bfv1.html Handbook of Texas Online VERTEBRATE PALEONTOLOGY ref He has researched Late Triassic reptiles in India , such as phytosaur s, rhynchosaur s, and prolacertiformes . He is best known for his work on vertebrates recovered in the 1980s from the Post Quarry in the Late Triassic Cooper Canyon Formation Dockum Group of West Texas . The material includes the large rauisuchian Postosuchus , which was named for the nearby town of Post, Texas Post . It also included controversial specimens Chatterjee identified as being avian Protoavis . The identification of these specimens as avian would push back the origin of birds by at least 75 million years. ref name Bio http www.depts.ttu.edu museumttu PaleoWebsite chatterjee.html Paleontology Division Dr. Sankar Chatterjee ref In 2008, Chatterjee and Rick Lind designed a 30 inch unmanned aerial vehicle with a large, thin rudder inspired by the Crest feathers crest of Tupandactylus . Genera named cla ... more details
image Coelurosauravus BW.jpg thumb right Artist s reconstruction of Coelurosauravus Avicephala is a possibly polyphyletic and therefore disused clade of diapsid reptile s that lived during the Late Permian and Triassic periods. Many species had odd specialized grasping limbs and prehensile tails, adapted to arboreal and possibly aquatic animal aquatic lifestyles. Description The name Avicephala means bird heads , in reference to the distinctive triangular skulls of these reptiles that mimic the shape of bird skulls. A few avicephalans, such as Hypuronector , even appear to have had pointed, toothless, bird like beaks. This cranial similarity to birds has led a few scientists to theorize that birds descended from avicephalans like Longisquama , though a majority see the similarity simply as Convergent evolution convergence . This similarity may also have led to the possible misidentification of the would be first bird , Protoavis . ref name renesto2000 Renesto, S. 2000 . Bird like head on a chameleon body new specimens of the enigmatic diapsid reptile Megalancosaurus from the Late Triassic of northern Italy. Rivista Italiana di Paleontologia e Stratigrafia , 106 157 180. http users.unimi.it rips 106 106N2.html Abstract ref Avicephalans possessed a variety of odd and distinctive characteristics in addition to their bird like skulls. Some displayed unique dermal appendages, such as the feather like dorsal plumes of Longisquama , and the laterally oriented rib like rods of Coelurosauravus , which supported membranes and may have been used to glide from branch to branch in an arboreal habitat. Another avicephalan group, the drepanosauridae drepanosaurid s, featured a suite of bizarre, almost chameleon like skeletal features. Above the shoulders of most species was a specialized hump formed from fusion of the vertebrae, possibly used for advanced muscle attachments to the neck, and allowing for quick forward striking movement of the head perhaps to catch insects . Many ha ... more details
Automatic taxobox name Drepanosaurs fossil range Late Triassic , fossil range 220 216.5 image Drepanosaurus unguicaudatus.JPG image width 250px image caption Fossil specimen of Drepanosaurus unguicaudatus taxon Drepanosauromorpha authority Renesto et al. , 2010 subdivision ranks Subgroups display children 1 Drepanosaurs members of the clade Drepanosauromorpha are a group of strange reptile s that lived during the Carnian stage of the late Triassic Period , between 220 and 216 million years ago. ref name renestoetal2009 Renesto, S., Spielmann, J.A., and Lucas, S.G. 2009 . The oldest record of drepanosaurids Reptilia, Diapsida from the Late Triassic Adamanian Placerias Quarry, Arizona, USA and the stratigraphic range of the Drepanosauridae. Neues Jahrbuch f r Geologie und Pal ontologie Abhandlungen , 252 3 315 325. doi 10.1127 0077 7749 2009 0252 0315. ref The various species of drepanosaurid were characterized by odd specialized grasping limbs and often prehensile tails, adaptions for arboreal tree dwelling , and or possibly aquatic lifestyles. Fossil s of drepanosaurs, also known as Simiosaurs monkey lizards , have been found in Arizona , New Mexico , New Jersey , England , and northern Italy . The name is taken from the family s namesake genus Drepanosaurus , which means sickle lizard , a reference to their strongly curved claws. Description Image Megalancosaurus BW.jpg thumb left Megalancosaurus preonensis restoration Drepanosaurs are notable for their distinctive, triangular skulls, which resemble the skulls of bird s. Some drepanosaurs, such as Hypuronector , had pointed, toothless, bird like beak s. This similarity to birds may have led to the possible mis attribution of a drepanosaur skull to the would be first bird , Protoavis . ref name renesto2000 Renesto, S. 2000 . Bird like head on a chameleon body new specimens of the enigmatic diapsid reptile Megalancosaurus from the Late Triassic of northern Italy. Rivista Italiana di Paleontologia e Stratigrafia , 106 ... more details
. ref name ACetal86 Archaeopteryx and Protoavis In 1984, Sankar Chatterjee discovered fossils which ... to be around 210 to 225 million years old, have been assigned the name Protoavis . ref name Chatterjee91 ... have rejected the claims that Protoavis was an earlier bird or, alternatively, that it existed at all ... more details
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