The mystery of the ant-lion (Commentary on Job, part 8)

The next surviving verse commentary is on Job 4:11. The Armenian mrjownariwtsn (մրջունառիւծն) is a calque on the Greek μυρμηκολέων (literally 'ant-lion') of the Septuagint. The Hebrew is lysh (ליש), which just means 'lion.' So where did 'ant-lion' come from? Perhaps relevant is Strabo's Geography 16.4.15, which describes a region on the Red Sea where 'elephants and lions called ants (μύρμηξιν) abound.' Is the ant-lion an ant or a lion or neither? And why did the LXX use this word here?

In any event, Stepanos interprets the compound word as a description of Satan:

“The ant-lion perished for lack of food” (4:11)
 Satan is a lion toward sinners and an ant toward the righteous. Some people read with a question ‘lion and the voice of a lioness’ (4:10).