Mountain bike helmets cover lower on the skull. Try a few and see if you like them. I did a couple of weeks ago and was pleasantly surprised to find they fit well, were comfortable on my Frankenstein shaped noggin, and had clearance in the back for my ponytail and bandanna knots, while still covering the base of the skull more effectively than most road bike helmets.

However I got a Bell Formula MIPS, mostly because I wanted a hi-vis yellow helmet and it was among the few REI had in stock in that color. There was also a very comparable Giro, but I got the Bell. Not much difference between 'em, although the Giro strap is softer, more comfortable and less fussy.

My older Bell Solar was more oval shaped, which initially seemed better suited to my skull. But the newer Bell was shaped more like the Giro, and both of those were comfortable as well. No complaints after two weeks and a few rides in summer heat.

The Bell Formula MIPS seems more minimal than the Bell Solar, but that's due in part to less stuff protruding out the back. It probably still offers adequate coverage. But if I had to go with a mountain bike helmet instead that would have been fine. They fit well too and didn't look dorky once the visors were removed.