• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Feel the intensity, not your equipment. Maximum image quality. Minimum weight. The new ZEISS SFL, up to 30% less weight than comparable competitors.

Microstructural and crystallographic evolution of palaeognath (Aves) eggshells (1 Viewer)

Fred Ruhe

Well-known member
Seung Choi, Mark E Hauber, Lucas J Legendre, Noe-Heon Kim, Yuong-Nam Lee & David J Varricchio, 2022

Microstructural and crystallographic evolution of palaeognath (Aves) eggshells

bioRxiv 2022.07.12.499761 (preprint)
doi: https://doi.org/10.1101/2022.07.12.499761

Free pdf and abstract: https://www.biorxiv.org/content/10.1101/2022.07.12.499761v1.full.pdf


The avian palaeognath phylogeny has been recently revised significantly due to the advancement of genome-wide comparative analyses and provides the opportunity to trace the evolution of the microstructure and crystallography of modern dinosaur eggshells. Here, eggshells of all major clades of Palaeognathae (including extinct taxa) and selected eggshells of Neognathae and non-avian dinosaurs are analysed with electron backscatter diffraction. Our results show the detailed microstructures and crystallographies of (previously) loosely categorized ostrich-, rhea-, and tinamou-style morphotypes of palaeognath eggshells. All rhea-style eggshell appears homologous, while respective ostrich-style and tinamou-style
morphotypes are best interpreted as homoplastic morphologies (independently acquired)
Ancestral state reconstruction and parsimony analysis additionally show that rhea-style eggshell represents the ancestral state of palaeognath eggshells both in microstructure and crystallography. The ornithological and palaeontological implications of the current study are not only helpful for the understanding of evolution of modern and extinct dinosaur eggshells, but also aid other disciplines where palaeognath eggshells provide useful archive for comparative contrasts (e.g. palaeoenvironmental reconstructions, geochronology, and



Users who are viewing this thread