But a bird's heavier than feathers.

Eggs were laid long before birds even evolved. If that's the criteria then the question becomes much easier to answer.

I mean, as considered by Aristotle, et al, the question was really asking "If you have a sequence of alternating events going infinitely far into the past, which came first?", which is more a math problem than a biology problem. (To which Aristotle, admirably, reached the conclusion that there wasn't a first event and it was a meaningless question.) It was only in the context of the Biblical creation that people decided it had a definitive answer (the chicken), and like 70% of "the egg came first" is really saying "Biblical creation was wrong!!1!", which is fun at first but kind of boring in the long haul.

A more useful point of meditation in the modern world is this: which is more important, the design (the egg) or the implementation (the chicken)? Was the chicken "created" when the first egg containing the design for a chicken was laid, or when the first chicken was fully implemented (the egg-laying chicken)?

Obvious parallels to technology, engineering, and startups, etc.