Which sources would preserve the soft tissues of an early mammal? Check all that apply.

Soft tissues are most likely to be preserved when an organism is trapped in amber or kept frozen, because these conditions slow decay. Amber in Russia, frozen soil in the Arctic, and ice sheets in Greenland can preserve soft tissues. Shale and sandstone usually preserve hard parts as fossils, while foraminifera are tiny shelled organisms rather than a preservation source for an early mammal.

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