Complex sentence: Many "Smilodon" specimens have been excavated from asphalt seeps that once acted as natural carnivore traps, wherein animals were accidentally trapped and became bait for predators that came to scavenge, but were then trapped themselves.
Split into simpler sentences: Many "Smilodon" specimens have been excavated from asphalt seeps that once acted as natural carnivore traps. Animals were accidentally trapped in the seeps and became bait for predators that came to scavenge, but these were then trapped themselves.