Research press release


Communications Biology

Palaeontology: New predatory diving dinosaur species identified

現生種の潜水鳥類(ペンギン、ウミスズメなど)に似た流線型の体を持つ非鳥類型恐竜の新種を記述した論文が、Communications Biologyに掲載される。この知見は、流線型の体を持つ非鳥類型獣脚類(二足歩行をする肉食恐竜の一種)の初めての事例となる。

今回、Yuong-Nam Leeたちは、モンゴルのウムヌゴビ県で出土した化石標本に含まれる遺骸化石を調べて、新種を特定し、Natovenator polydontusと命名した。この名称は、「多くの歯を持ち、遊泳する狩猟者」という意味だ。この化石標本は、ほぼ完全な骨格化石で、頭蓋骨、脊柱、1本の前肢、2本の後肢の残骸が含まれている。



A new species of non-avian dinosaur with a streamlined body similar to those of modern diving birds, such as penguins and auks, is described in a study published in Communications Biology. The findings represent the first case of a non-avian theropod — a type of carnivorous dinosaur that walked on two legs — to have a streamlined body.

Yuong-Nam Lee and colleagues identified the new species by examining the fossilised remains of a specimen from the Omnogovi Province, Mongolia. They have named the species Natovenator polydontus, meaning “swimming hunter with many teeth”. The specimen is a mostly complete skeleton and features the skull, spinal column, one forelimb, and the remains of two hindlimbs.

The authors report several adaptations that suggest that Natovenator may have been a semiaquatic diving predator, including a streamlined body similar to those of modern diving birds — with ribs that point towards its tail — and a long neck similar to modern water birds such as geese. These adaptions may have reduced the drag that Natovenator would have been subjected to when swimming and helped it to catch prey. The authors also speculate that the unusually high number of teeth that Natovenator had in relation to the size of its jaw could indicate that it ate a fish or insect-based diet, however further evidence — such as the fossilised remains of its stomach contents — is needed to confirm this.

Analysis of the evolutionary relationships between Natovenator and other theropod dinosaurs indicate that it was closely related to halszkaraptorines — a group of non-avian theropods that previous research has suggested may have been adapted for a semiaquatic lifestyle, similar to modern day waterfowl. Together, the findings indicate that Natovenator was a semi-aquatic diving predator and provide further insight into theropod evolution.


doi: 10.1038/s42003-022-04119-9


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