In the last two years seemed to have proliferated in basal theropods and plazopánvými all. Start would be with předloňským taxon Tawa (described by Nesbitt et al. 2009), which represented the first refreshment in an otherwise poorly known theropod evolution phase - the phase that precedes the emergence neoteropodů. Since the early plazopánvých which represents such Eoraptor , it's the first neoteropodům (like celofyzisovi) still quite a long way. Tawa is on this road a certain milestone - the authors even has its morphology close to the ideal "relays" between herrerasaury and celofyzoidy. Perhaps most surprising was that tawy addition to the traditional phylogenetic analysis revealed celofyzoidy parafyl as consisting taxa of increasingly advanced teropodům closer. The truth is that this strange conclusion, further studies have not confirmed. But it turned out that Nesbitt et al. you are absolutely right blend herrerasauřích neoteropodích and characters. Just because it might as Andrew Cao in his "megamatrici" uncover tawu as basal herrerasaura (herrerasauridy standing outside), whereas Martinez et al. (2011) found it to be representative nejbazálnějším monofyletických celofyzoidů.
in 2010, followed description of a new herrarasaura, originating from the legendary Argentine Ischigualasto formation. Sanjuansaurus Alcober & Martinez, 2010 (description was published in a new way, a completely open-access journal ZooKeys ), although not so important phylogenetic implications, but it was interesting from the perspective of evolution and ecology of early dinosaurs. Again, today confirmed the indisputable fact that the diversity of dinosaurs plazopánvých was already in the earliest Upper Triassic very good, which moves in the first branch on dinosaur evolution in the past. He showed a somewhat surprising fact that large predatory dinosaurs were common in the elderly, Carnic Ischigualastu than later in the Los Colorados in the burrow. The authors used it to defend a model of early, comprehensive evolutionary radiation of dinosaurs (which held Brusatte et al. 2010) in contrast to hypotheses, the importance of assigning a significant extinction at the turn of Karni and Nora (Langer et al. 2009).
And finally, earlier this year, arrived here the blog has several mentioned Eodromaeus (described by Martinez et al. 2011), which slid into the basal Eoraptor (guaibasauridních) sauropodomorfů and he was replaced by an attractive position early theropod. It would even say that it succeeded tawu's position "relays," because the analysis published along with a description of took exactly the same position, have been Tawa in cladograms Nesbitt et al: between herrerasaury and neoteropody.
And now, barely three months after eodromeovi, comes another early theropods with the right to change the existing ideas about the evolution of the group. Dinosaur is a great name chosen Daemonosaurus chauliodus (described by Sues et al. 2011) comes from the famous "Ghost Ranch" (Ghost Ranch) in novomexickém Chinle Formation, and specifically from the site called Coelophysis Quarry. This formation already in the pan-avianní Having made a name for paleontology chindesaurem (problematic plazopánvým dinosaur, perhaps early herrerasaurem) dromomeronem (lagerpetidem - nejbazálnější agent ever known dinosauromorfů line), or perhaps already mentioned tawou. All of these taxa, however, come from the Hayden Quarry, while Daemonosaurus was found in Coelophysis Quarry. Abstract (the only part of the study, which is available to me) the reader to the fundamentals of: the earliest theropods appear in the Argentine Karna and rapidly undergoing radiation, until the turn of the Triassic and Jurassic (about some 17 million years later), but their fossil record remains very thin and does not fully understand the evolutionary history of the group. Daemonosaurus course it would be helpful. The abstract shows that along with the eodromeem tawou and this taxon is the itch to bridge the gap between the morphological and herrerasaury neoteropody. Andrew Cao once again brings further information and states that according Sues et al. should be Daemonosaurus more basal than Tawa. Even closer are the basis of theropods and herrerasauři Eoraptor .
démonosaura authors also considered a relic of the "initial radiation" dinosaurs, and because it occurs in layers dated to the very end of the Triassic period (along with much more advanced, neoteropodním celofyzisem), believe that in my time already represented a kind of anachronism. Abstract (and again Andrew Cao) draws attention to several traits. First, it the pleziomorfie that actually show that the new taxon outside neoteropody: for example, is the last tooth in the jaw rather far back, just below the eye socket. Autapomorfickými but are tilted forward and strongly předčelistní enlarged teeth on the bones. Bowed are the bones and teeth teeth, while excessive dimensions still have teeth in front of the maxilla. This strange teeth démonosaura clearly distinguishes it from all contemporary neoteropodů, although - as noted by A. Cau - tens of millions of years later, the same characters develop (each independently *) basal oviraptorosauři (as Incisivosaurus , or it may be synonymous Protarchaeopteryx ) skanzoriopterygidní and "sapeornitidní" birds or noasauridní ceratosaur Masiakasaurus . Cao also found one more interesting (though no doubt acquired convergent) similarity with oviraptorosaury, and short předočnicovou part of the skull. Similarities in the gearing according to him, indicate the same food. The question remains just what - it could be a fruit, but also insects (for maziakasaura again speculated rybožravosti). Sues et al. (2011) note that the unique shape of the teeth and skull shows unexpected morphological diversity of theropod already in this early stage in their evolution. Holotype
démonosaura skeleton forms, cataloged as CM 76,821, consisting of skull, cervical vertebrae and ribs. It shows an animal with a total length of about 1.5m, hence relatively small to medium size.
in 2010, followed description of a new herrarasaura, originating from the legendary Argentine Ischigualasto formation. Sanjuansaurus Alcober & Martinez, 2010 (description was published in a new way, a completely open-access journal ZooKeys ), although not so important phylogenetic implications, but it was interesting from the perspective of evolution and ecology of early dinosaurs. Again, today confirmed the indisputable fact that the diversity of dinosaurs plazopánvých was already in the earliest Upper Triassic very good, which moves in the first branch on dinosaur evolution in the past. He showed a somewhat surprising fact that large predatory dinosaurs were common in the elderly, Carnic Ischigualastu than later in the Los Colorados in the burrow. The authors used it to defend a model of early, comprehensive evolutionary radiation of dinosaurs (which held Brusatte et al. 2010) in contrast to hypotheses, the importance of assigning a significant extinction at the turn of Karni and Nora (Langer et al. 2009).
And finally, earlier this year, arrived here the blog has several mentioned Eodromaeus (described by Martinez et al. 2011), which slid into the basal Eoraptor (guaibasauridních) sauropodomorfů and he was replaced by an attractive position early theropod. It would even say that it succeeded tawu's position "relays," because the analysis published along with a description of took exactly the same position, have been Tawa in cladograms Nesbitt et al: between herrerasaury and neoteropody.
démonosaura phylogenetic position of two different analysis. Andrew Cao and his unpublished "megamatrice" revealed a new taxon of all nejbazálnějšího plazopánvého, outside the example Eusaurischia (+ sauropodomorfové theropods). Let us consider the more interesting results - as silesauridů ptakopánvých (including 245 million years old asilisaura - how far would such a thing moved the emergence of dinosaurs!) Eodromea bazálnějšího than herrerasauři (Martinez et al. 2011 saw vice versa) or Eoraptor, which remains the sauropodomorfem, but no longer guaibasauridem (as uncovered Martinez et al. 2011). Sues et al. (2011), the authors describe démonosaurova, in contrast, offer a somewhat more conservative tree. Eoraptor in it, as in earlier studies, has a basal position within the theropods, which Tawa and Daemonosaurus fill the gap, which spans between him and neoteropody. Since the internal structure neoteropodů is very close to what he discovered Nesbitt et al. (2009) - including controversial parafyletických celofyzoidů, I believe that the Sues et al. built directly on the matrix. (Modified from a theropoda.blogspot.com en.wikipedia.org)
And now, barely three months after eodromeovi, comes another early theropods with the right to change the existing ideas about the evolution of the group. Dinosaur is a great name chosen Daemonosaurus chauliodus (described by Sues et al. 2011) comes from the famous "Ghost Ranch" (Ghost Ranch) in novomexickém Chinle Formation, and specifically from the site called Coelophysis Quarry. This formation already in the pan-avianní Having made a name for paleontology chindesaurem (problematic plazopánvým dinosaur, perhaps early herrerasaurem) dromomeronem (lagerpetidem - nejbazálnější agent ever known dinosauromorfů line), or perhaps already mentioned tawou. All of these taxa, however, come from the Hayden Quarry, while Daemonosaurus was found in Coelophysis Quarry. Abstract (the only part of the study, which is available to me) the reader to the fundamentals of: the earliest theropods appear in the Argentine Karna and rapidly undergoing radiation, until the turn of the Triassic and Jurassic (about some 17 million years later), but their fossil record remains very thin and does not fully understand the evolutionary history of the group. Daemonosaurus course it would be helpful. The abstract shows that along with the eodromeem tawou and this taxon is the itch to bridge the gap between the morphological and herrerasaury neoteropody. Andrew Cao once again brings further information and states that according Sues et al. should be Daemonosaurus more basal than Tawa. Even closer are the basis of theropods and herrerasauři Eoraptor .
démonosaura authors also considered a relic of the "initial radiation" dinosaurs, and because it occurs in layers dated to the very end of the Triassic period (along with much more advanced, neoteropodním celofyzisem), believe that in my time already represented a kind of anachronism. Abstract (and again Andrew Cao) draws attention to several traits. First, it the pleziomorfie that actually show that the new taxon outside neoteropody: for example, is the last tooth in the jaw rather far back, just below the eye socket. Autapomorfickými but are tilted forward and strongly předčelistní enlarged teeth on the bones. Bowed are the bones and teeth teeth, while excessive dimensions still have teeth in front of the maxilla. This strange teeth démonosaura clearly distinguishes it from all contemporary neoteropodů, although - as noted by A. Cau - tens of millions of years later, the same characters develop (each independently *) basal oviraptorosauři (as Incisivosaurus , or it may be synonymous Protarchaeopteryx ) skanzoriopterygidní and "sapeornitidní" birds or noasauridní ceratosaur Masiakasaurus . Cao also found one more interesting (though no doubt acquired convergent) similarity with oviraptorosaury, and short předočnicovou part of the skull. Similarities in the gearing according to him, indicate the same food. The question remains just what - it could be a fruit, but also insects (for maziakasaura again speculated rybožravosti). Sues et al. (2011) note that the unique shape of the teeth and skull shows unexpected morphological diversity of theropod already in this early stage in their evolution. Holotype
démonosaura skeleton forms, cataloged as CM 76,821, consisting of skull, cervical vertebrae and ribs. It shows an animal with a total length of about 1.5m, hence relatively small to medium size.
Very nice démonosaura reconstruction, which stands for Jeffrey Martz. Great shows are forward projecting teeth; protopeří is artistic license (even though his presence is not unlikely). (Source: smithsonianscience.org)
* Remember, however Cauovu unpublished hypothesis "velkooviraptorosaurů" , according to which "sapeornitidi" skanzoriopterygidi and classical forms oviraptorosauři example, eliminating all other Maniraptora, which falls between avialanní birds (= closer to to living birds than to deinonychosaurům). This hypothesis driven by similarities in shape and proportions of the skull and předočnicové noticeably enlarged teeth, Cao himself but rejected it because of his "megamatrici" required 26 steps more than the standard topology.
Sources:
- http://en.wikipedia.org/wiki/Daemonosaurus
- http://theropoda.blogspot.com/2009/12/tawa-hallae-nesbitt-et- Al-2009-ED-il.html
- http://theropoda.blogspot.com/2011/04/daemonosaurus.html
- Alcober PC, Martinez RN 2010 A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina. ZooKeys 63: 55–81
- Brusatte SL, Nesbitt SJ, Irmis RB, Butler RJ, Benton MJ, Norell MA 2010 The origin and early radiation of dinosaurs. Earth-Sci Rev 101: 68–100
- Langer MC, Ezcurra MD, Bittencourt JS, Novas FE 2009 The origin and early evolution of dinosaurs. Biol Rev Camb Philos Soc 85(1): 55–110
- Martinez RN, Sereno PC, Alcober OA, Colombi CE, Renne PR, Montañez IP, Currie BS 2011 A basal dinosaur from the dawn of the dinosaur era in southwestern Pangaea. Science 331(6014): 206–10
- Nesbitt SJ, Smith ND, Irmis RB, Turner AH, Downs A, Norell MA 2009 A complete skeleton of a Late Triassic saurischian and the early evolution of dinosaurs. Science 326(5959): 1530–3
- Sues H-D, Nesbitt SJ, Berman DS, Henrici AC 2011 A late-surviving basal theropod dinosaur from the latest Triassic of North America. Proc R Soc Lond B doi:10.1098/rspb.2011.0410
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