Complex sentence: Unlike a disk-shaped spiral galaxy, Messier 87, as with most giant elliptical galaxies, has no distinctive dust lanes and it has an almost featureless, ellipsoidal shape that diminishes in luminosity with distance from the center.
Split into simpler sentences: Unlike a disk-shaped spiral galaxy, M87 has no distinctive dust lanes. Instead, it has an almost featureless, ellipsoidal shape typical of most giant elliptical galaxies, diminishing in luminosity with distance from the center.