Indeed the evidence is now so strong that birds evolved from theropod dinosaurs that recently the class aves was redesignated as a subclass of reptilia. The new fossil is thought to be around 155 million years old and is called Xiaotingia. Pharyngula has a nice rundown on what the new fossil means.
The reclassification of Archaeopteryx is expected to be exploited by creationists, who are likely to pick up on the fact that scientists are appearing to change their mind about the fossil's iconic status as the first bird, but this would be wrong, said Lawrence Witmer, professor of anatomy at Ohio University.
The reclassification does not alter the fact that Archaeopteryx possessed features that are both reptilian and avian, nor does it change the fact that birds evolved from feathered dinosaurs, he said. "What this does is change our view of Archaeopteryx. For 150 years it's been our oldest and most prominent bird. Part of the reason why we should care about this is that Archaeopteryx is probably one of the most famous fossils ever," Professor Witmer said. "It changes a lot inhttp://www.blogger.com/img/blank.gif terms of how we view early birds, and how early birds evolved."
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