Invertebrates are a type of creature without a skeleton.

He is an expert in ethology, and his research is highly regarded worldwide.

He is studying about ancient animal worship.

As the name suggests, onychophorans are a unique group of animals that have claws.

He has a deep interest in paleozoology.

He is an expert in paleozoology and has a deep knowledge about the ecology of dinosaurs.

Anthropozoonosis, or animal-derived infectious diseases, have the potential to spread between humans and animals.

He is receiving treatment for obsessive-compulsive disorder.

In mathematics, it is important to examine the parity of numbers.

This metal has very high malleability.