Core excercises without getting on the floor?

I use a stability ball for some of my exercises. That adds a core component. So, for example, biceps curls resting one foot on the ball. Triceps extensions and chest presses while lying in bridge position on the ball. Lateral rows while sitting on the ball.

Are you able to plank?

ETA: Also shoulder exercises. Y's and T's on the ball.

And bird-dogs

I'm looking through my book of strength exercises to see what else can be done without lying on the ground. I have not tried these, but:

• Abs crunches on the ball (lying with your low and mid-back on the ball, knees at 90 degrees, feet hip-width apart, upper back and shoulders slightly below the top of the ball. Fingertips behind ears, elbows wide, chin up. Exhale and contract abs, lifting shoulders up, low back pressed firmly against the ball. Pause at top, inhale, and slowly return to start without releasing abs.
• Waist crunch and twist on the ball. From seated position, roll down until midback is supported on the ball. Keep head and neck aligned with your spine and parallel to the floor. Hold a 3-8lb weight in both hands, keeping it vertical against your chest. Inhale. Exhale, contracting abs and lift your head and neck, twisting your left shoulder toward your right hip. Hold, then inhale and slowly release back to center. Repeat to other side. Do all your reps, alternating right to left.
• Kneeling pelvic tilt. Kneel on mat with wrists under shoulders and knees under hips, back in neutral spine alignment. Inhale, filling belly with air. Exhale forcefully, pulling abs in tight, drawing belly button toward spine. With one fluid motion, reverse curve in low back and tilt your hips under. Release and repeat.
• Sitting pelvic tilt on stability ball. Sit up tall on ball, feet parallel, hip width apart. rest hands on knees. Keep back straight, in neutral spine alignment. Inhale, filling belly with air. Exhale forcefully, pulling abs in tight, drawing belly button toward spine. With one fluid motion, reverse curve in low back by tucking your hips under, rolling the ball forward 1". Release and repeat.

One other thing: My book states that lying in the supine position is not advised for pregnant women past the first trimester. Maybe Google "core exercises during pregnancy"? There could be others.

there are tons and tons of core exercises that you dont have to be on the floor. Hanging knee or leg raises, dead lifts, oblique band twists , weighted side bends, slam ball, battling ropes, the list goes on and on and on,

Google standing abs