Complex sentence: Except certain salamandrid salamanders that can extrude sharp venom-tipped ribs, amphibians are not known to actively inject venom, most toxic amphibians are instead known to be poisonous to touch or eat.
Split into simpler sentences: Except certain salamandrid salamanders that can extrude sharp venom-tipped ribs, amphibians are not known to actively inject venom. Most toxic amphibians are instead known to be poisonous to touch or eat.