This small flathead (?) was on shallow reef on the northern GBR. Any help naming it would be appreciated. Picture is with a Sony 90mm macro lens. Thanks.

How big was it?  If it's quite small it looks reminiscent of a triplefin, except for the mouth, but a large mouth triplefin seems close?  https://www.inaturalist.org/taxa/338587-Ucla-xenogrammus/browse_photos

Thanks Chris, it was small.. The bottom jaw does look a little bit long but that must be it.