GENERAL GEOLOGY

Detailed explanation-1: -The two main types of compound eyes trilobites had were holochroal and schizochroal eyes. The main difference is that holochroal eyes have many lenses covered by one cornea, whereas schizochroal have many lenses, each one covered by a separate cornea.

Detailed explanation-2: -Trilobites can also be divided into three longitudinal parts (short direction); a head called the cephalon, an abdominal region called the thorax, and a tail region called the pygidium. Trilobites were covered with an exoskeleton. Trilobites’ exoskeletons were segmented, and they could roll into balls for protection.

Detailed explanation-3: -The trilobite body is also divided lengthwise into three regions or tagmata: a head or cephalon, a middle region (thorax) composed of several to many articulated segments, and a tail plate called a pygidium, which consists of fused segments.

Detailed explanation-4: -An extinct trilobite has been found to have a type of eye unlike anything seen before or since. The unique structure in a group of trilobites, dubbed a ‘hyper-eye’, features lenses that each cover a separate group of receptors that form multiple eyes within each other.