The Mesopotamian tradition of extispicy of dead sacrificial sheep remained remarkably consistent throughout Old Babylonian, Middle Babylonian and Neo-Assyrian times (1, p xiii).
The tradition was kept continuous by texts such as Barutu and KAR 423, and liver models such as the British Museum's Old Babylonian sheep liver model (1, p xiii-xiv). The sheep's entire organs were scrutinized during these autopsies.
Starr, Ivan. 1990. Queries to the Sungod: Divination and Politics in Sargonid Assyria. Helsinki: Helsinki University Press.