Mesozoic Biological Events and Ecosystems in East Asia
Mesozoic Biological Events and Ecosystems in East Asia covers a wide range of topics, encompassing palaeoenvironments, palaeoecosystems and important vertebrate, invertebrate and plant fossils, some found in amber with excellent preservation of delicate morphological features. Fifty-three authors from a number of different disciplines – geochronology, palaeontology, stratigraphy, sedimentology, tectonics and geochemistry – contribute to the 18 articles in the volume.
Well-preserved fossils and rocks continue to be found from marine and terrestrial sediments across East Asia. Over some years, the palaeontological and geological evidence discovered from this region has significantly improved our understanding of Mesozoic environments. In discussing feathered dinosaurs, primitive birds, early mammals, diverse insects, amber inclusions, the oldest-known flowers and research utilizing new, advanced methods, this volume explores Earth's history in even greater detail. What other exciting discoveries are waiting to be unveiled in the future?
New prospects on the cranial evolution of non-avialan paravian theropods based on geometric morphometrics
Published:July 29, 2022
Rui Pei, Xing Xu, 2022. "New prospects on the cranial evolution of non-avialan paravian theropods based on geometric morphometrics", Mesozoic Biological Events and Ecosystems in East Asia, S-C. Chang, D. Zheng
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The cranial morphology of theropod dinosaurs has been used to examine the phylogeny, ontogeny, ecology and biomechanics of the clade. Previous studies have recognized that paedomorphosis and peramorphosis occurred multiple times throughout theropod evolution, with skull paedomorphism being one of the major changes during the transition from non-avialan theropods to birds. This study supplemented previous works with more detailed sampling of the morphological data of non-avialan paravians. Principal component analyses based on the cranial geometry confirm that the small-bodied non-avialan paravians have paedomorphic skulls compared with the early-diverging theropods, but independent peramorphosis is also observed in various groups. The secondary elongation of the preorbital portion of the cranium was present in both the late-diverging troodontids and the late-diverging dromaeosaurids, but it was achieved through different morphological configurations in these two lineages.
- biologic evolution
- Far East
- Lower Cretaceous
- principal components analysis
- statistical analysis
- Jehol biota
- Yanliao biota