在《主采坦耶的教导》一书，提到主奎师那有六类化身，其中有一类称为年代化身，指的是在四个年代（名为萨提亚，特瑞塔，杜瓦帕尔，喀历；也称为金银铜铁）里，奎师那以不同的化身到来教导适合那个年代的自觉之法，书中对显现在萨提亚和特瑞塔年代的化身没有列出名字，经向krishna.com查询，年代化身是以下四位：

         年代                化身
萨提亚年代Satya-yuga      汉萨Hamsa
特瑞塔年代Treat-yuga      亚格纳Yajna
杜瓦帕尔年代Dvapara-yuga  奎师那Krishna
喀历年代Kali-yuga         柴坦亚Caitanya

以下是英文回信的原文
SB 11th canto 5th chapter talks about the various incarnations of God in different yugas. Verses 20 thru 32 lists the incarnations. In Satya yuga the Lord is glorified by the names Hamsa, Suparna etc. In Treta yuga He is glorified by the names Visnu, Yajna, Prsnigarbha etc. In Dvapara yuga the Lord appears with a dark blue complexion and Jiva Gosvami says the characteristics mentioned are indicative of Krishna, though He appeared at the end of Dvapara yuga. In Kali yuga it is Lord Caitanya.
 
So the yuga avatras would be Hamsa, Yajna, Krishna and Caitanya.
Hope this helps.
Your servant,
Gopi Gita D. Dasi