Pandoran autopsy for mutoid ability

Hi, I am triyng to figure out witch pandoran autopsy is necessary to unlock the first ability of mutoids. Have already completed Mindfragger and Poisonworm autopsies but it is still locked. Any idea? Thanks.

Finally unlocked after Acheron autopsy… Text should be changed to relect that…

It is after almost any autopsy, worms and sentinels don’t count as they don’t have any interesting abilities.