Well, I got the recent news about that feathered dinosaur. Apparently Ken Ham and other Creationists have declared it to be 100% bird despite lacking a bony breast muscle anchor birds have and possessing dinosaur features like clawed fingers and teeth. This brings me back to a point I was thinking about including in Creationism is in a State of Chaos, though I rewrote it partway through to cover bigger issues, rather than list miscellaneous details. I’ve seen some Creationists claim that the more famous archeopteryx was all bird. I’ve seen others claim it was all reptile/dinosaur. It will not surprise me if this latest fossil triggers more flip-floppery from Creationists trying to shoehorn it into the categories they’re comfortable with.
The evolutionary answer doesn’t necessitate glossing over contradictions. It’s a theropod dinosaur that has evolved some early bird features. All birds are theropod dinosaurs, since they descended from theropod dinosaurs. They’re a subcategory that developed identifying features on top of the ones that define theropod dinosaurs. All birds are theropods, but not all theropods were birds. Inheritance and polymorphism are important concepts here. Theropods beget theropods by the rule of inheritance, but new theropods can have traits that are unique to them, which is polymorphism. One branch of theropod descendents evolved traits on top of the theropod template that we use to define what a bird is. Those theropods that possess some bird traits but not all of them are a part of the transition from the general category of theropod to the specific category birds.
One big problem with Creationism is that its proponents are trapped in Platonic idealism, treating “bird” as if it were defined by some ideal independent of the actual feathered creatures making tweeting noises outside my window. Evolutionary taxonomy starts with the actual organisms that existed and defines them based on their features and how they’re passed on. Platonic Creationism looks at the creatures that exist now and try to define past creatures based on modern categories. It’s kind of like trying to assign the telegraph to the category of smart phone or desktop computer. All three are electric devices that communicate to others in a binary code. The telegraph lacks the numerous features that define the other two categories, so it doesn’t fit into either.
Aside: The invention metaphor isn’t a good fit for evolution in general, since you can move features horizontally across branches. Smart phones are phones, but they’re also computers because some people thought it was a good idea to add those computer features to a phone. When organisms do seem to copy a different branch, you can pretty much count on the copier doing a superficially similar end result in its own distinct way instead of simply copying and pasting DNA from the other branch. Living organisms larger than a handful of cells generally don’t borrow features from other branches in the tree of life, outside of some ‘oddball’ cases like making something out of a deactivated ERV.