spin-, spino-, spini-

(Latin: thorn, prickle; by extension, "backbone", the spinal cord)

spinosaurid (s) (noun), spinosaurids (pl)
One of a large group of huge, flesh-eating dinosaurs: The spinosaurids, dating back to the Middle or Late Jurassic period and existing in the Cretaceous period, developed long spines jutting up from their backbones. They were also named by the German paleontologist Ernst Stromer von Reichenbach in 1915.
spinosaurus (s) (noun), spinosauri (pl)
A very large and carnivorous dinosaur: The extinct spinosaurus from the Late Cretaceous period is known as the "spine lizard". It was named by the German paleontologist Ernst Stromer von Reichenbach in 1915.
spinose (adjective); more spinose, most spinose
Pertaining to something covered with spines: In her biology class at school, Ivy looked through her microscope at the spinose legs of a fly!
spinosuchus (s) (noun) (no pl)
The extinct genus of trilophosaurid allokotosaur: The nonexistent fossil reptile spinosuchus, meaning "spined crocodile" dates back to the Late Triassic of Texas, USA, and was named by von Huene in 1932.
spinous (adjective); more spinous, most spinous
Referring to something which has the form of a thorn: Jim had a bad accident but was lucky in that the spinous process fracture along his lumbar vertebrae could heal without any longterm damage.
spinulate (adjective) (not comparable)
Concerning an animal or something covered with little spines: Doug's face was full of spinuate and prickly little needlelike hairs which were very scratchy!
spinulation (s) (noun), spinulations (pl)
The formation of spinules or spines: Susan read in her biology book that spinulation occurred on the extremities or on the surface of a body of epicuticular rootage or origin.
spinule (s) (noun), spinules (pl)
A small or minute spine or prickle: Gary found it interesting that the spinule, a tadpole-like larva, was very active just after being born from its parent Botryllus.

There were such tiny spinules on the wee little hedgehog!

spinulescent (adjective); more spinulescent, most spinulescent
Descriptive of something that is spiny, or rather somewhat thorny: In his biology class at school, Jack read that the species Aloe buchananii was a spinulescent perennial herb with stems up to 20 cm long and 5 cm thick!
spinuliferous (adjective); more spinuliferous, most spinuliferous
Relating to something that bears small spines: Little Tiny accidentally touched a spinuliferous plant with her fingers and made them bleed!
spinulose (adjective); more spinulose, most spinulose
Pertaining to a plant which is covered with minute spines: The spinulous or spinulose woodfern of the genus Dropteris, also called the buckler-fern, has fronds that uncurl upwards and such ferns exist in cool temperate regions of the Northern Hemisphere.
spiny (adjective); spinier, spiniest
1. Concerning plants and animals that have or are covered with barbs or quills: Good examples of spiny animals and plants can be the sea urchin, fish with spiny fins, hedgehogs, a spiny cactus, or even the rosebush stems which have lots of thorns, all of which are to protect them from predators!
2. Pertaining to something which is difficult to handle or to understand: For her math homework Mary had a very spiny or puzzling problem to solve for the next day.
3. Regarding something which is shaped like a thorn or barb: The crochet hook little Timmy found in his mother's sewing box was quite thin and spiny and looked dangerous!

The grasshopper sitting in the sun had two thin spiny legs, ready for jumping.