A variety of ornithopods and related cerapods had thin cartilaginous plates along the outside of the ribs; in some cases, these plates mineralized and were fossilized.
Razni ornitopodi i srodni cerapodi imali su tanke ploče od hrskavice na vanjskoj strani rebara; u nekim slučajevima te su se ploče mineralizirale i fosilizirale.