The event that occurs in the cytoplasmic division of plant cells but not animal cells is the formation of a cell plate.

Here's why:

* Cell plate formation: During cytokinesis (cytoplasmic division) in plants, a cell plate forms in the middle of the parent cell. This cell plate, made of cellulose, gradually expands outward, eventually fusing with the existing cell walls, dividing the parent cell into two daughter cells.

* Animal cell division: Animal cells lack rigid cell walls. Instead, they undergo cytokinesis through a process called cleavage furrow formation, where the plasma membrane pinches inward, eventually separating the daughter cells.

Therefore, cell plate formation is a unique characteristic of plant cell division, differentiating it from animal cell division.