Seals were oftentimes passed on as heirloom items making them difficult for dating.
Uruk is more naturalistic with plants and animals and priest-king.
The transtion from one Early Dynastic phase to another is clearly reflected in changing designs of cylinder seals.
When we think of Early Dynasic seals, banquet scenes and combat/conquest scenes ought come to mind; and also the Early Dynastic I images of animal figures that were dovetailed (ie, overlapped and intertwined). Early Dynastic III seals heralded fine muscle rendering. However, animal scenes had been abandoned in favor of religious and banquet iconography. Natural motifs resurged in the Akkadian era, but these differed from their predecessors by incorporating the muscle detail developed in the ED III (and included landscapes).
Early Dynastic I
With the abandonment of mythological and religious symbolism, the brocade style is the hallmark of Early Dynastic I cylinder seals.
The brocade style is characterized by decorative animals and plants supplemented by meaningless textile-like designs. The animals are typically dovetailed to such an extent that these scenes are sometimes referred to as crossing scenes. The musculature of the animals remains undefined and these are more of abstract designs using animals' shapes, rather than lifelike depictions.
Early Dynastic II
Imaginative characters return to cylinder seals.
The animal contest soon becomes popular: lions attack cattle, which are defended by guardian figures, especially the bull-man (now with an ornamental girdle and side-locks beneath his horns) and bearded hero. The figures intertwine into intricate patterns, though plastic rendering (ie, musculature) and linear designing is undisciplined.
Another hallmark of Early Dynastic II cylinder seals is the advent of inscriptions, though these were occasional and only became widespread in Early Dynastic III designs. Later in the Early Dynastic II era, other imagery such as the banquet scene begins to appear. These showed one or two seated figures with attendants and a plentiful abundance of food.
Early Dynastic III
Seal-making reaches its utmost as miniature relief-carving during the Early Dynastic II era.
Figures become more massive and are skilfully modelled; lions and guardians alike often face the viewer and more ornamental ruminants are introduced; combat/conquest scenes are punctuated with empanlled inscriptions; and designs are occasionally divided into two horizontal registers.
In addition to secular topics such as combat/conquest and banquets, Early Dynastic III seals are characterized by mythological/ceremonial scenes. While initially esoteric to modern scholars, they have become clearer as more Sumerian literature is translated. So far as materials, seals of semi-precious stone are now found, even sometimes capped with silver or, rarely, made of solid gold.
Early Dynastic IIIa
Typical of the ED IIIa is a contest scene with animals kind of crossing.
Cylinder seal motifs now include the ever-flowing vase and the six-locked hero.
Natural landscape. Mountains, etc. Another is that we do NOT see the crossed animals. We see mythological scenes however. With AKkadian seals we have a much richer variety of scenes. Figures are uncrossed, more straight, we have landscapes, sometimes mythological scenes portrayed. That's how we distinguish ED from Akkadian seals. Much more naturalistic in Akkadian also, with muscle detail.