On this day, in 1253, Mindaugas....

On this day, in 1253, Mindaugas was crowned as King of Lithuania.

The arms are similar to the modern arms of Lithuania, except that the knight's shield has a different symbol, which is repeated in the crest.

Anybody knows what that is?

[https://commons.wikimedia.org/wiki/File:Vytis_COA_Lithuania.Codex_Bergshammar.png#/media/File:Vytis_COA_Lithuania.Codex_Bergshammar.png] https://commons.wikimedia.org/wiki/File:Vytis_COA_Lithuania.Codex_Bergshammar.png#/media/File:Vytis_COA_Lithuania.Codex_Bergshammar.png

File:Vytis COA Lithuania.Codex Bergshammar.png - Wikimedia Commons