Term Name:	spine appendage
Synonyms:	spiny appendage
Definition:	A hard, thorny or needle-like structure which occurs on various animals. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism. Spines are often formed of keratin. Other animals with spines are hedgehogs, spiny mice and at least two ornithischian dinosaurs.
Ontology:	Uberon Ontology [UBERON:0008260]