The current model of Elliptical Galaxy Taxonomy and Growth is shown in this chart.
In the Standard Vibration Model, the Elliptical Galaxies are similar to Thermonuclear explosions in space where there is little pressure against them from external densities, magnetism or Dark Matter. The more pressure against them the stranger the shape. Stars in Ellipticals are starved not of material to form stars, but they lack the strong magnetic core to cause rotation. This lack of a strong magnetic core in the Galaxy causes its stars to loose energy. Over time the Baryon no longer has information to transmit and becomes Dark Matter.