Diocletian's palace was a most influential building. The carving of the entablature has little sense of Classical Greek design. Here is the precedent that culminates in the carvings in Hagia Sophia more than two centuries later. Image: An edited combination of two images from The Palace of Diocletian at Split.
of the cornice and frieze of the Temple of Vespasian, c. 90 A.D. Rome:
Small gap in the dentils, egg and dart in a different place, here; compare to Diocletian's mausoleum. (René Seindal)