As suggested by SproutSchon ask the reseller what BIOS version is installed or make sure you can return the motherboard if it won't support the CPU. There's absolutely nothing on the box or on the motherboard that indicates the BIOS version; testing it with a CPU seems to be the only way (or contacting the manufacturer with the serial number, but most resellers obviously won't do that for free). I went with H97 and Z97 motherboards because I knew the CPU would be supported and I also wanted better audio and Intel LAN controllers.
Have you considered buying from a local store that could flash the BIOS if need be?