Quadrangular and circular shields in iconography
Pictures kindly provided by my friend VA are images from the Chola kingdom of the drAviDa country.
1) mahiShamardinI(mahAlakShmI); 2) kaushikI(mahAsarasvatI); 3) mahiShamardinI(mahAlakShmI); 4) mahAkAlI. It should be noted that this is one of the few rare depictions of the deity mahAsarasvatI the killer of shuMbha and nishuMbha. In the mArkaNDeya purANa mahAsarasvatI is aided by the mAtR^ikA goddess in this act. However, in most cases even the mAtR^ikA-s are iconographically combined with a generic mahAlakShmI rather than the mahAsarasvatI whom they accompany in the above text.
Note the use of both quadrangular and circular shields in the Tamil country in Chola temples.
A modern print from the a fire-cracker box sold in the days of yore during dIpAvalI without any shield and an odd-looking shUla but no shield. Generally, one could find high-quality art on the cracker boxes which were again typically produced by artists from the drAviDa country. But the lack of the shield suggests loss of familiarity with real combat using swords.