alula

1.Also, in all of these photos, you cannot see "hanging" alula or primary coverts often shown by Rook.

同时，所有照片都看不到『悬挂起来』羽或大覆羽，通常秃鼻会有这个特徵。

2.The team also noted a hinged flap near the base of the wing, called an Alula, which is deployed at right angles to the wing, which may be being used as a air flow-control device.

这个意到，根附近铰接副，被称为，对成直角配置，它可能被用来作为空气流量控制装置。