What specific structural feature in ALH84001 was considered one of the primary lines of evidence implying ancient life?

Answer

Worm-like forms resembling fossilized bacteria when viewed under an electron microscope (Morphology).

One of the three primary lines of evidence presented for ancient life in ALH84001 was morphology, describing worm-like shapes observed microscopically that resembled fossilized bacteria.

What specific structural feature in ALH84001 was considered one of the primary lines of evidence implying ancient life?
discoverylifealienbacterium