2023-01-11 テキサス大学オースチン校(UT Austin)
この化石は、パタゴニアのチリ地域から発見された獣脚類(現生鳥類とその近縁種を含む恐竜グループ)の最初の記録である。研究者たちは、大きな鎌のような爪を持つ巨大なメガラプトルや、現在の現生種も含むグループの鳥類を発見しました。
UTジャクソン大学地質科学科のジュリア・クラーク教授のもとで博士課程研究の一環としてこの研究を行った主著者サラ・デイビスは、「大量絶滅に至るまでのパタゴニアの動物相は実に多様でした」と述べています。「大型獣脚肉食動物と小型肉食動物、そしてこれらの鳥類群が、他の爬虫類や小型哺乳類と共存していたのです。」
この研究は、Journal of South American Earth Sciencesに掲載されました。
<関連情報>
- https://www.jsg.utexas.edu/news/2023/01/fossils-reveal-dinosaurs-of-prehistoric-patagonia/
- https://www.sciencedirect.com/science/article/abs/pii/S0895981122004497
パタゴニア、マガラネス-オーストラリア海盆の白亜紀後期(カンパニアン-マーストリヒテン)地域からの獣脚類の新記録と白亜紀末期の獣脚類の多様性に関する洞察 New records of Theropoda from a Late Cretaceous (Campanian-Maastrichtian) locality in the Magallanes-Austral Basin, Patagonia, and insights into end Cretaceous theropod diversity
Sarah N.Davis,Sergio Soto-Acuña,Roy A.Fernández,Jared Amudeo-Plaza,Marcelo A.Leppe,David Rubilar-Rogers,Alexander O.Vargas,Julia A.Clarke
Journal of South American Earth Sciences Available online: 17 December 2022
DOI:https://doi.org/10.1016/j.jsames.2022.104163
Abstract
The end Cretaceous mass extinction was marked by a dramatic change in biodiversity, and the extinction of all non-avian dinosaurs. To understand the diversity of dinosaur clades prior to this event, as well as recovery by avian dinosaurs (birds), we need a better understanding of the global fossil record. However, the fossil record from southern localities, particularly southernmost (>60°S) South America, has only recently begun to be described. Discoveries from Patagonia are important to accurately assess global trends in dinosaur diversity, particularly during the latest Cretaceous before the Cretaceous/Paleogene (K/Pg) mass extinction event. Here we describe new theropod dinosaur specimens, representing both associated material and isolated elements, from Upper Cretaceous (Campanian-Maastrichtian) deposits of the Río de las Chinas Valley, Magallanes-Austral Basin, Chile. These discoveries include the southern-most known occurrences of several theropod clades outside of Antarctica, including megaraptorids, unenlagiines, enantiornithines and ornithurines. Notably, these remains provide much needed time-constrained records of smaller theropods, including birds, which are less often recovered from Upper Cretaceous deposits. While fragmentary, these fossils are the first records of theropods from Chilean Patagonia, and provide insight into the distribution of avian and non-avian theropods in southern high latitude ecosystems prior to the K/Pg mass extinction event. Sampling from this region is still sparse, and more fossils from age-controlled sections are needed to accurately assess global extinction dynamics through the end Cretaceous.
