Conversely, reading about such animals, my first thought is "can we please sequence their DNA already"?
That's one critical reason for being very upset about us extincting countless species, even those that do not play any significant role in keeping the planet habitable - losing all these genes means losing pages from a book that contains ready-made biotech, and information that helps to explain how things came to be (which helps explain why it works).
Interestingly, vertibrates rely heavily on metals for the strength of their skeletons via the calcium mineral matrix calcium hydroxiapatite, up to 50% by volume and 70% by weight of human bone is a modified form of hydroxyapatite.
And many of our enzymes contain metals (magnesium, a lot), and some transport proteins too (famously haemoglobin).
Zinc is essential in humans for DNA replication. We need chromium and molybdenum in tiny amounts for blood sugar control and hunger regulation.
Though none of these seem quite as spectacular as metal plares body parts!
And various other wasps have heavy metals concentrated near the apex of their mandibles.
There's also resilin, an elastic-like compound(?) that concentrates energy at certain parts of insect joins, used during jumping, or other fast movements.
https://www.popularmechanics.com/science/animals/a12957/foun...