A triangle shape in Guelph, ON

I was driving to an apointment and. decided to take a quieter more rural route than usual. At a particularity unpopulated strecth of thr road I saw ahead of me an unuasually large completey black bird. It was croutched over some roadkill. This was a road with one lane in each direction. The bird was close to the middle line on my side of the road. The bird saw my car approaching and spread its wings and took off. When the bird did so I was completely shocked. Its wing tips spread from the line on the soft shulder on my side to most of the width of the next lane. At first before it spread its wings like this I asumed it was a turkey vulture which is very common in my area. But as it raised to fly off and it turned to the side a bit and spread its wings I could see it was absolutely not a turkey vulture. This bird was imense and was completely jet black from beak to tail. No markings at all. And its head shape was very sharply triangular with what seamed like a disproportionatley small sharp beak. It was not a raven, crow, hawk or any species I could identify. I got a very clear look at it and I am certain of what I saw. One other very interesting note is - my windows were open and I heard the initial flap as it took off - which was very loud most likely due to its size. I have looked online for similar reports and have found nothing so far. Thanks!