A new Lower Cretaceous bird from China and tooth reduction in early avian evolution

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2009, Volume and Issue: 277(1679), P. 219 - 227

Published: July 8, 2009

A new avian genus and species, Zhongjianornis yangi gen. et sp. nov., is reported from the Lower Cretaceous lacustrine deposits of Jiufotang Formation in Liaoning, northeast China. The taxon characterized by possessing following combination features: upper lower jaws toothless, snout pointed, humerus with large robust deltopectoral crest, second phalanx major manual digit longer than first phalanx, unguals alular digits similar length significantly shorter corresponding penultimate phalanges, tibiotarsus slender more twice tarsometatarsus, metatarsal IV other metatarsals. Phylogenetic analysis indicates that phylogenetically basal to Confuciusornis dominant Mesozoic groups, Enantiornithes Ornithurae, therefore provides significant information regarding diversification birds Early Cretaceous. It also represents most bird completely lacks teeth, suggesting tooth loss was common expected early evolution beak appeared independently several lineages, probably as a response selective pressure for weight reduction. Finally, presence enlarged humeral crest suggests shares such Jeholornis, Sapeornis distinctive mode adaptation flight contrasting seen advanced birds, which instead possess an elongated sternum prominent keel.

Language: Английский

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Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds

Geosciences, Journal Year: 2012, Volume and Issue: 2(3), P. 157 - 177

Published: Sept. 14, 2012

At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution apparently modern feathers occurred within Maniraptora, basal the avian transition, with asymmetrical pennaceous suited flight present in most recognized avian, Archaeopteryx lithographica. number extinct primitive morphotypes among non-avian dinosaurs continues increase new discoveries; some these resemble birds. As result, between phylogenetically widely separated taxa been described as homologous. Here we examine Aves and compare structures those found dinosaurs. We conclude that "rachis dominated" tail Confuciusornis sanctus enantiornithines not equivalent "proximally ribbon-like" juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis unusual rectrices supports interpretation they modified feathers. Because this seen living birds, build on current understanding molecular morphogenesis suggest hypothetical developmental model formation rachis dominated

Language: Английский

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Anurans from the Lower Cretaceous Jehol Group of Western Liaoning, China

PLoS ONE, Journal Year: 2013, Volume and Issue: 8(7), P. e69723 - e69723

Published: July 26, 2013

Background To date, the Lower Cretaceous Jehol Group of western Liaoning, China has yielded five monotypic genera anurans, including Liaobatrachus grabaui, Callobatrachus sanyanensis, Mesophryne beipiaoensis, Dalianbatrachus mengi, and Yizhoubatrachus macilentus. However, validity distinctness these taxa have been questioned. Methodology/Principal Finding We provide a comprehensive analysis frogs that includes re-examination published as well an examination number new specimens collected over past 10 years. The results show previously named can be referred to three species one genus–Liaobatrachus L. beipiaoensis comb. nov. macilentus nov.. diagnosis is revised, provided for each this genus. also establish zhaoi sp. nov., on basis dozen well-preserved from locality. This taxon distinguished by unique combination characteristics, relatively long hind limbs, rounded rather than triangular acetabulum, gradually-tapering cultriform process parasphenoid. In addition, unnamed frog higher horizon, which narrow sacral diapophyses particularly legs, different represents another form anuran in Biota. Conclusion/Significance Comparisons with other Mesozoic extant anurans primary phylogenetic both suggest member crown-group forms polytomy leiopelmatids (Ascaphus Leiopelma) remaining (Lalagobatrachia).

Language: Английский

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A New Species of Pengornithidae (Aves: Enantiornithes) from the Lower Cretaceous of China Suggests a Specialized Scansorial Habitat Previously Unknown in Early Birds

PLoS ONE, Journal Year: 2015, Volume and Issue: 10(6), P. e0126791 - e0126791

Published: June 3, 2015

We describe a new enantiornithine bird, Parapengornis eurycaudatus gen. et sp. nov. from the Lower Cretaceous Jiufotang Formation of Liaoning, China. Although morphologically similar to previously described pengornithids Pengornis houi, IVPP V18632, and Eopengornis martini, morphological differences indicate it represents taxon Pengornithidae. Based on information this specimen we reassign V18632 The well preserved pygostyle elucidates morphology element for clade, which is unique in among Mesozoic birds. Similarities with modern scansores such as woodpeckers may specialized vertical climbing clinging behavior that has not been inferred early preserves pair fully pennaceous rachis-dominated feathers like those holotype martini; together pygostyle, discovery lends evidence hypotheses have had functional significance. This adds diversity ecological niches occupied by enantiornithines if correct reveals are remarkable amount locomotive differentiation Enantiornithes.

Language: Английский

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Early evolution of the biological bird: perspectives from new fossil discoveries in China

Journal of Ornithology, Journal Year: 2015, Volume and Issue: 156(S1), P. 333 - 342

Published: April 20, 2015

Language: Английский

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