It doesnt matter how long they are, their still fingernails no matter what.
Do you mean black claws or back claws? Well, the answer is yes, to both. Their claws are blackish-looking on the inside (although on the outside they are translucent like human fingernails), and yes, female red-eared sliders have both front and back claws, just like the males. The difference is that the claws of the male are usually much longer.
All birds Talons and Claws are also made of Keratin. The same as Human fingernails, Rino Horn, Porcupine and other such things.
The rattle is made of keratin, the same group of substances that make up the human's outer layer of skin, fingernails, claws, horns, etc.
A cat's claws are made out of the same material that human fingernails are made out of: Keratin. A cat's nails are constantly growing like a human's or a dog's, but grow in layers instead of length. Newly grown claws are covered by a protective outer layer that the cat removes by "sharpening" his claws. However, a cat's claw is firmly attached to first toe bone. This ensures that the claws cannot be pulled out during hunting, fighting or climbing. Tendons and special joints are what enable a cat's claws to retract and flex.
Calcium
To note a few things, dinosaurs had tails, and humans do not. Dinosaurs had snouts, unlike us. They also had claws, while we have keratin fingernails. Many types of dinosaurs had bony armor, horns, or headcrests, which humans do not have.
Fingernails are made from a protein called "Keratin".
due to cuticle and protein keratin
Human Brains. With fingernails.
Fingernails & hair. The cornea. Tendons.
Depends on the nail. Toenail or fingernail?
20- 10 fingernails/10 toenails