Early layer - 18 weeks. Whixh breed did it?

[nvdirtfreak]

Hello all, I am a first time chicken owner and discovered my first egg yesterday! Small and brown and surprisingly perfect. I am curious which breed it belongs to, though. I have 4 Americuanas (I'm assuming since the egg is brown that it wasn't one of them), 2 Gold Sex Links (who I think is responsible), 2 Rhode Island Reds and 2 Black Australorps. Are any of these breeds known for laying early? Are the other breeds likely to start laying soon as well?

 

[sourland]

One of the sex links is most likely the early maturing pullet. Look for the hen with the brightest, largest comb and wattles. Congratulations!