[INDOLOGY] Sacrificial Tortoise?

[George Hart]

Akanāṉūṟu 361 (probably dating to the first 2 centuries CE) mentions a sacrifice in which a tortoise is placed in a fiery sacrificial pit (tittiyam) for the gods "whose flowers do not fade" to eat.  This is also referred to 5 or 6 centuries later in the Cīvakacintāmaṇi (2878).  I have never heard of such a ritual and am wondering whether it is mentioned in Sanskrit.  The poem uses the image quite beautifully: a man separated from his beloved as he crosses the wilderness to get wealth addresses his heart, telling it that it must not think of her and must not be like the tortoise in the sacrificial pit longing for its cool, shadowed pond.  George Hart