ibero-mesornis

from the GNU version of the Collaborative International Dictionary of English.

• noun A sparrow-sized fossil bird of the Lower Cretaceous having a strutlike pectoral bone and vestigial tail; found in Spain; considered possibly the third most primitive of all birds.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun sparrow-sized fossil bird of the Cretaceous period having a vestigial tail; found in Spain; considered possibly the third most primitive of all birds