actually, they are fall in the category of analogous groups. as they do the same function but have different structure.
Quil is to porcupine as spine is to cactus
protects it from predators.
A spine.
'Spine' is another word for 'thorn'.
Spine
stem. if i am wrong please correct me
Only if the spine doesn't get stuck in their throat.
Skeletal System.
Lemurs, being animals who have developed notocords, that is, spine, belong to Phyllum Chordata.
Roundworms (scientific name: Nematoda) are invertebrates, as they do not have a spine.
It hurts but if the spine is carefully removed, it should cause nothing more than a bit of discomfort.
vertebrae make up the spine (backbone) of vertebrate animals.