Crotalocephalina

Crotalocephalina is a genus of trilobite that lived during the Middle Devonian period, approximately 393.3 to 382.7 million years ago. This genus is part of the family Phacopidae, known for their well-developed eyes and ornate exoskeletons. Crotalocephalina is characterized by its large, bulbous glabella (the central part of the head), and its long, curved genal spines (projections from the side of the head).

Description[edit | edit source]

Crotalocephalina trilobites have a semi-circular cephalon (head) with a large, bulbous glabella that often has a furrowed or wrinkled surface. The glabella is flanked by large, crescent-shaped eyes that provide a wide field of vision. The thorax consists of numerous segments, each with a pair of broad, flat pleurae (side lobes). The pygidium (tail) is typically small and semi-circular, with a smooth or slightly wrinkled surface.

The most distinctive feature of Crotalocephalina is the pair of long, curved genal spines that extend backwards from the cephalon. These spines, which can be as long as the body itself, may have served a defensive function.

Distribution and habitat[edit | edit source]

Fossils of Crotalocephalina have been found in Devonian rocks in many parts of the world, including North America, Europe, and North Africa. These trilobites lived in marine environments, where they were likely bottom-dwellers.

Taxonomy[edit | edit source]

The genus Crotalocephalina was first described by the French paleontologist Joachim Barrande in 1846. It includes several species, such as Crotalocephalina gibbus and Crotalocephalina crassifrons.