Read ‘em：新種の草食恐竜の化石発見

A previously unknown species of plant-eating dinosaur roamed on an island off the south coast of England around 125 million years ago, new research has found.

The dinosaur would have been the size of a large American bison and weighed around a ton, according to Jeremy Lockwood, a doctoral researcher at the University of Portsmouth in the United Kingdom and lead author of a study on the prehistoric creature.

Fossilized footprints found near the skeleton show the dinosaur was probably a herding animal, Lockwood said, adding: “Possibly large herds of these dinosaurs may have been thundering around if spooked by predators on the floodplains over 120 million years ago.”

The dinosaur fossil, comprising 149 bones, was discovered on the Isle of Wight in 2013 and is the most complete skeleton found in the UK in more than a century, the research published in the Journal of Systematic Palaeontology said.

The bones were found by avid local fossil collector Nick Chase, who died of cancer in 2019.

“Nick had a phenomenal nose for finding dinosaur bones – he really was a modern-day Mary Anning,” Lockwood said, alluding to the famous 19th-century paleontologist, in a news release. “He collected fossils daily in all weathers and donated them to museums. I was hoping we’d spend our dotage collecting together as we were of similar ages, but sadly that wasn’t to be the case.”

The new dinosaur species has been named Comptonatus chasei after Chase and the location where he found the skeleton, Compton Bay.

The researchers were able to determine the skeleton belonged to a new dinosaur species because of unique features, such as its jaw and particularly large pubic hip bone.

Lockwood described the discovery as “a remarkable find,” explaining: “It helps us understand more about the different types of dinosaurs that lived in England in the Early Cretaceous.”

Mike Greenslade, general manager of the conservation charity National Trust on the Isle of Wight, praised the “extraordinary discovery.”

“Finding the most complete dinosaur in the UK in a century not only showcases the island’s palaeontological significance but also underscores the importance of preserving our landscapes for future generations to explore and learn from,” Greenslade said.

“Nick Chase’s remarkable find and Jeremy Lockwood’s dedicated research are a testament to the incredible history waiting to be uncovered here,” he added.

およそ１億２５００万年前、現在の英イングランド南部沖の島に生息していた新種の草食恐竜の化石が、英国史上、最も完全な形で見つかった。

論文を発表した英ポーツマス大学のジェレミー・ロックウッド氏によると、この恐竜はアメリカバイソンほどの大きさで、体重は１トン前後と推定される。

骨格の近くにあった足跡の化石は、この恐竜が恐らく草食動物だったことを物語っているとロックウッド氏は指摘。「１億２０００万年以上前、この恐竜の大きな群れが、氾濫原（はんらんげん）で捕食動物に驚かされ、轟音（ごうおん）を立てて駆け回っていたのかもしれない」と想像している。

１４９本の骨で構成されるこの恐竜の化石は、イングランド沖のワイト島で２０１３年に発見された。学術誌に発表された論文によると、英国でこの１００年あまりの間に見つかった化石の中では最も完全な形で残っていた。

化石を発見した地元の収集家ニック・チェイス氏は、１９年にがんのため死亡した。

ロックウッド氏はチェイス氏について、「恐竜の骨を見つける驚異的な嗅覚（きゅうかく）を持っていた。まさに現代のメアリー・アニング（１９世紀の著名古生物学者）だった」と回想し、「彼はどんな天候でも化石を採集して博物館に寄贈してくれた。私たちは年齢が近いので、老後は一緒に化石採集をして過ごしたいと思っていたが、かなわなかった」とチェイス氏をしのんだ。

新種の恐竜は、発見者のチェイス氏と発見場所のコンプトン湾にちなんで「Ｃｏｍｐｔｏｎａｔｕｓ　ｃｈａｓｅｉ」と命名された。