Insights into the early evolution of modern avian physiology from fossilized soft tissues from the Mesozoic

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2025, Номер 380(1920)

Опубликована: Фев. 27, 2025

Modern birds (Neornithes) are the mostly highly modified group of amniotes, bearing little resemblance to other extant sauropsids. Archaeopteryx , with its nearly modern wings but plesiomorphic skeleton, demonstrated more than 160 years ago that soft tissue specializations preceded skeletal modifications for flight. Soft tissues thus great importance understanding early evolution avian physiology. Most commonly, traces integumentary system preserved; exceptional discoveries include remnants organs. Together, these have helped elucidate lungs, ovaries, plumage and beak in diverging birds. These fossils reveal many important adaptations efficient digestion, high oxygen intake, reduced body mass improved wing structure, all which serve improve aerial capabilities and/or meet energetic demands this costly form locomotion, evolved within first 20–30 Myr evolution. preservation also provides clues ecology may even extinction certain groups. However, current fossil record Mesozoic is almost entirely limited Early Cretaceous thus, from Late potential drastically transform our interpretation available data. This article part theme issue ‘The biology respiratory system’.

Язык: Английский

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Evidence of proteins, chromosomes and chemical markers of DNA in exceptionally preserved dinosaur cartilage

National Science Review, Год журнала: 2019, Номер 7(4), С. 815 - 822

Опубликована: Дек. 16, 2019

A histological ground-section from a duck-billed dinosaur nestling (Hypacrosaurus stebingeri) revealed microstructures morphologically consistent with nuclei and chromosomes in cells within calcified cartilage. We hypothesized that this exceptional cellular preservation extended to the molecular level had features common extant avian Histochemical immunological evidence supports situ of extracellular matrix components found cartilage, including glycosaminoglycans collagen type II. Furthermore, isolated Hypacrosaurus chondrocytes react positively two DNA intercalating stains. Specific staining is only observed inside cells, suggesting endogenous nuclear material survived fossilization. Our data support hypothesis cartilage preserved at Mesozoic material, suggest remnants once-living chondrocytes, their DNA, may preserve for millions years.

Язык: Английский

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Anatomy of Parahesperornis: Evolutionary Mosaicism in the Cretaceous Hesperornithiformes (Aves)

Life, Год журнала: 2020, Номер 10(5), С. 62 - 62

Опубликована: Май 14, 2020

The Hesperornithiformes constitute the first known avian lineage to secondarily lose flight in exchange for evolution of a highly derived foot-propelled diving lifestyle, thus representing truly aquatic birds. First unearthed 19th century, and today from numerous Late Cretaceous (Cenomanian-Maastrichtian) sites distributed across northern hemisphere, these toothed birds have become icons early evolution. Initially erected as taxon 1984 by L. D. Martin, Parahesperornis alexi is two most complete hesperornithiform specimens discovered date has yet be fully described. P. contributes significantly our understanding birds, despite often being neglected favor iconic Hesperornis. Here, we present full anatomical description based upon nearly collections University Kansas Natural History Museum, well an extensive comparison other taxa. This study reveals possess mosaic basal traits found among taxa, indicating transitional form describes broad evolutionary patterns within Hesperornithiformes, highlighting significance not only incredible example ecological specializations, but also modern bird evolution, they are last divergence pre-modern diversification.

Язык: Английский

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Hummingbird-sized dinosaur from the Cretaceous period of Myanmar

Nature, Год журнала: 2020, Номер 579(7798), С. 245 - 249

Опубликована: Март 11, 2020

Язык: Английский

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Description and osteohistology of two early immature enantiornithines (Aves: Ornithothoraces) from the Early Cretaceous Jehol Biota

Geobios, Год журнала: 2024, Номер unknown

Опубликована: Авг. 1, 2024

Язык: Английский

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Two new Early Cretaceous ornithuromorph birds provide insights into the taxonomy and divergence of Yanornithidae (Aves: Ornithothoraces)

Journal of Systematic Palaeontology, Год журнала: 2020, Номер 18(21), С. 1805 - 1827

Опубликована: Ноя. 1, 2020

Yanornithidae is an Early Cretaceous ornithuromorph clade that preserves the oldest direct evidence indicative of a piscivorous diet in avian evolution. The family hitherto contained only single genus Yanornis and two putative species. yanornithids are readily distinguishable from other Mesozoic avians having long rostrum packed with numerous teeth. Despite discoveries dozens specimens, little known about taxonomical ecomorphological diversity this due to lack comparative studies. Here, we describe new yanornithid taxa, Similiyanornis brevipectus gen. et sp. nov. Abitusavis lii nov., based on nearly complete skeletons Jehol Biota. We perform reassessment rectify assignments published Yanornis-like materials. results show contains three genera species, which demonstrate wide range limb proportions exceed degree seen L early clades.http://zoobank.org/urn:lsid:zoobank.org:pub:64C621AF-48B7-499E-9F41-B6023B2E5F78

Язык: Английский

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Osteohistology of the Scapulocoracoid of Confuciusornis and Preliminary Analysis of the Shoulder Joint in Aves

Frontiers in Earth Science, Год журнала: 2021, Номер 9

Опубликована: Апрель 13, 2021

As key components of the tetrapod pectoral girdle, scapula and coracoid have played a significant role in evolution forelimb locomotion among terrestrial vertebrates. The transition from rigid fused scapulocoracoid ancestral non-avian theropods to presumably more flexible separated scapula-coracoid early birds is considered be one morphological transitions related rapid refinement flight. In most Mesozoic (e.g., Enantiornithes Ornithuromorpha) crown are separate (unfused), with few exceptions flightless paleognaths). contrast, Confuciusornis , basal pygostylian Early Cretaceous Jehol Biota known thousands specimens, remain plesiomorphically fused. This raises questions regarding influence shoulder girdle architecture on avian paravian joint has never previously been investigated using histology, thus morphology only inferred superficially. order better understand this birds, we make first histological study glenoid . results demonstrate that both consist cancellous compact bone, fibrolamellar parallel-fibered structure. A thin layer calcified cartilage present fossa surface, representing remnants articular surface for humerus. Both histology computed tomography reveal fully fused, forming synostosis. Humeral suggests studied individual was nearing completion its year growth, suggesting before skeletal maturity achieved, as paleognaths, whereas plesiomorphic condition fusion occurs late ontogeny. We hypothesize secondarily evolved suggest primary factor responsible may decrease mechanical stimulation at relative other volant linked unique flight style taxon. Further investigation into paravians extant will help clarify evolution.

Язык: Английский

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Fossilized cell nuclei are not that rare: Review of the histological evidence in the Phanerozoic

Earth-Science Reviews, Год журнала: 2021, Номер 216, С. 103599 - 103599

Опубликована: Апрель 16, 2021

Язык: Английский

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Nuclear preservation in the cartilage of the Jehol dinosaur Caudipteryx

Communications Biology, Год журнала: 2021, Номер 4(1)

Опубликована: Сен. 24, 2021

Previous findings on dinosaur cartilage material from the Late Cretaceous of Montana suggested that is a vertebrate tissue with unique characteristics favor nuclear preservation. Here, we analyze additional in Caudipteryx (STM4-3) Early Jehol biota Northeast China. The fragment highly diagenetically altered when observed ground-sections but shows exquisite preservation after demineralization. It reveals transparent, alumino-silicified chondrocytes and brown, ironized chondrocytes. histochemical stain Hematoxylin Eosin (that stains nucleus cytoplasm extant cells) was applied to both demineralized chicken. two specimens reacted identically, one chondrocyte revealed fossilized threads chromatin. This second example chromatin material. These data show some original biochemistry preserved this further support hypothesis very prone fossilization perfect candidate understand DNA deep time.

Язык: Английский

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Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China

Journal of Systematics and Evolution, Год журнала: 2021, Номер 60(5), С. 1172 - 1198

Опубликована: Дек. 29, 2021

Abstract We describe six specimens consisting of cranial remains and associated partial presacral axial series belonging to ornithuromorph birds from the Changma locality Lower Cretacous Xiagou Formation northwestern Gansu Province, China. Comparison among is limited by paucity overlapping elements, their differing exposed views, and, in some specimens, poor preservation. Despite this, three separate taxa are represented, evidenced differences dentary dentitions: one specimen edentulous, another has sharp, closely spaced, relatively high‐crowned peg‐like teeth, a third preserves blunt, low‐crowned teeth placed communal groove, morphology previously reported adult only Hesperornithiformes. propose that may be referred Gansus yumenensis based on shared similarities with related Iteravis huchzermeyeri , including very similar dentition an edentulous premaxilla elongate, unfused frontal processes no palatal processes. The two other considered new taxa, for which we erect names Meemannavis ductrix gen. et sp. nov. Brevidentavis zhangi These confirm dominated contribute better understanding this important avifauna. observed variation dental hints at trophic diversity like ornithuromorphs penecontemporaneous Jehol Group northeastern

Язык: Английский

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