Figure above:

Imaginary animal, with the body o an eagle and the head of a lion, in gold and lapis lazuli, discovered in the ancient city of Mari (Syria), attributable to about 3000-2000 B.C. It is probably an image related to Ningirsu, the city god of Girsu, who was the god of spring thunderstorms and of the Tigris river floods. He was represented in the shape of a thunderbird with a lion’s head, out of which the thunder roared (Jacobsen 2005). The object is now in the National Museum of Damascus, Syria.

[Image: http://www.geometriefluide.com/pagina.asp?cat=sumeri]

Figure below:

High relief in copper from the Ninhursag temple at Tell al’ Ubaid (Iraq), attributable to about 2500 B.C., and now in the British Museum, London. The image shows the thunderbird with a lion’s head, through which the god Ningirsu, master of thunderstorms and floods, was represented. In the subsequent period, Ningirsu acquired gradually an anthropomorphic shape, whereas the animal became simply the emblem of the god. In still later times, the bird with a lion’s head, called Imdugud, became the principal antagonist against which the god fought (Jacobsen 2005).

[Image: http://www.ancientworlds.net/aw/Post/1288377]