I'm beginning to think China is a country paved with interesting fossils; every week I'm seeing something new published. This is another enantiornithine bird like the one I mentioned yesterday, only this fellow was caught as an embryo—it's all coiled around within a tight oval, a confusing jumble of bones with the skull on the left, looking down (if you can't sort it out in this picture, click on the image for a larger image with a diagrammatic key.)

The authors note a few interesting features: the bird is precocial, with feather traces present. It would have hatched as something a bit more advanced and active than your typical naked peeper. It's also lacking an egg tooth, but it's got regular teeth in its beak—as well as a long bony tail that make it look rather different from modern birds.

Zhou Z, Zhang F (2004) A precocial avian embryo from the lower Cretaceous of China. Science 306(5696):653.