Fukuipteryx prima: A New Cretaceous Bird from Japan

On November 14, a new Cretaceous bird in Japan was named and described. It was named Fukuipteryx prima!

Fukuipteryx is first Japanese mesozoic bird that was named. Its name means “primitive wing from Fukui”. It was found from Kitadani Formation in Fukui. Its wingspan is about 50cm wide. It lived in Early Cretaceous, about between 127 and 115 million years ago. Its fossil was under 1 years old when it lived. When it was alive, Kitadani Formation was the swamp near the river. It lived with animals like crocodile, turtles, and dinosaurs like Fukuiraptor and Fukuivenator.

Fukuipteryx has short tail like modern birds, but it has a lot of primitive points. In modern birds, tail bones are  completely stuck each other, but in Fukuipteryx, Shapes of each bones are seen. It shows the way how bird’ tails became shorter.

It has a thick wishbone like the letter “U”. Wishbone is the bone seen in front of chest bone in some reptiles, dinosaurs, and birds. It supports chest and shoulder muscles and help their breath. In modern birds, wishbone is fine and soft like a spring, but it of Fukuipteryx is more thicker and less flexibility.

It has three fingers with claws on each wing like dinosaurs. In modern birds, instep bones are stuck each other, but they are not stuck in Fukuipteryx.

On the other hand, it has a big bump that was stuck a muscle to raise its wing on its upper arm bone. It could flap strongly. It has both old points and new points. It was halfway of the step to flight.

Classification of Fukuipteryx from T. Imai, Y. Azuma, S. Kawabe, M. Shibata, K. Miyata, M. Wang, and Z. Zhou. 2019. An unusual bird (Theropoda, Avialae) from the Early Cretaceous of Japan suggests complex evolutionary history of basal birds. Communications Biology2(1):399:1-11

To surprise, Fukuipteryx branched before Jeholornis, an early bird with long tail. It shows that tail have become shorter many times in the evolution of birds and a linage including modern birds is only one of the example.

Fukuipteryx prima is very important species in the evolution of birds. Thank-you for reading.

Reference

• T. Imai, Y. Azuma, S. Kawabe, M. Shibata, K. Miyata, M. Wang, and Z. Zhou. 2019. An unusual bird (Theropoda, Avialae) from the Early Cretaceous of Japan suggests complex evolutionary history of basal birds. Communications Biology2(1):399:1-11

• Theropods: from Carnivorous Dinosaurs to Flying Birds
• written by Hattori Soki
• published in 30th June 2018
• (The official picture record of the exhibition in Fukui Prefectural Dinosaur Museum in 2018)

• 鳥肉以上、鳥学未満。
• written by Kawakami Kazuto
• published by Iwanami Shoten, Publishers
• published in 19th February 2019

• お知らせ 前期白亜紀における最も原始的な新属新種の鳥類化石を「フクイプテリクス・プリマ」と命名しました｜ 福井県立大学http://www.fpu.ac.jp/news/d153316.html
• (The article by Fukui University)

• 福井で発見の鳥類化石は新種　始祖鳥に次ぐ原始的な鳥類：朝日新聞デジタルhttps://www.asahi.com/amp/articles/ASMCG4FX4MCGPGJB009.html
• (The article by newspaper)