ブラジルで新種の小型恐竜の化石、歯がなく二足歩行

【リオデジャネイロＡＦＰ＝時事】約７０００万年前に生息していた新種の恐竜の化石がブラジルで発見された。歯がなく二足歩行で、発表した研究者らは「極めて珍しい」発見だと述べた。（写真はブラジル・クルゼイロドオエステで恐竜の化石を発掘する研究者ら。ブラジル国立博物館提供）
　見つかったのは体長約１メートル、体高約８０センチの小型の獣脚類。「ベルタサウラ・レオポルディナエ」と命名された。
　獣脚類はほぼ全てが肉食だと考えられていたが、不可解なことにこの新種は歯がなく、くちばしのような口を持っていた。
　ブラジル国立博物館が１８日に発表した声明によると、発見に関わった古生物学者らは「本当に驚きの発見だ」と述べた。
　英科学誌「ネイチャー」に掲載された論文は「ブラジルで発見された白亜紀の恐竜としては、骨が最もそろったものの一つ」だと説明している。
　この化石は南部パラナ州の農村部の道路脇で、２０１１年から２０１４年にかけて出土した。分析の結果、７０００万～８０００万年前の新種だということが判明した。【翻訳編集ＡＦＰＢＢＮｅｗｓ】

〔ＡＦＰ＝時事〕（2021/11/24-13:23）

Remains of a toothless, two-legged dinosaur species that lived some 70 million years ago has been discovered in Brazil, researchers said Thursday, calling it a very rare find.
The small dinosaur, which measured about a meter (three feet) long and 80 centimeters (two and a half feet) tall, is a theropod, a group whose members were almost all believed to be carnivores.
But puzzlingly, the new species -- dubbed Berthasaura leopoldinae -- has a beak-like mouth with no teeth.
That was a real surprise, the paleontologists who made the find said in a statement released by Brazil's National Museum.
They published their findings in the journal Nature, calling the discovery one of the most complete dinosaurs found from the Cretaceous period in Brazil.
The toothless part raises doubts about what kind of diet this animal had, said researcher Geovane Alves Souza, one of the study's authors.
It doesn't necessarily mean it didn't eat meat, though. Lots of birds, such as falcons and buzzards, eat meat with beaks. Most likely, it was an omnivore living in an inhospitable environment where it had to eat whatever it could.
The fossilized skeleton was found along a rural road in the southern state of Parana between 2011 and 2014.
Analysis revealed it was an entirely new species that lived between 70 million and 80 million years ago.
The species was named for Bertha Lutz, a revered Brazilian scientist and feminist who died in 1976, and for Maria Leopoldina, Brazil's 19th-century empress, who was a patron of the sciences.