Buenaspis

Buenaspis is a genus of extinct ptychopariid trilobites belonging to the family Conocoryphidae. These marine arthropods lived during the Early Cambrian period, specifically the Cambrian Series 2, Stage 4, approximately 514 to 509 million years ago. Fossils of Buenaspis have been primarily discovered in the Sirius Passet Lagerstätte of North Greenland.

Buenaspis is characterized by its relatively small size, typically reaching lengths of only a few centimeters. The cephalon (head shield) is semicircular, with well-defined glabella (central lobe of the cephalon). The thorax consists of several segments, and the pygidium (tail shield) is generally small and triangular. Distinctive features of Buenaspis include the presence of elongated genal spines extending from the cephalon and its well-preserved soft tissue, which has provided valuable insights into the anatomy and lifestyle of early trilobites. The soft tissue preservation, including appendages, digestive systems, and other internal organs, is a key aspect making Buenaspis an important fossil for paleontological research.

The name Buenaspis refers to the Buen Formation, the geological unit in which the fossils were found, and the Greek word "aspis," meaning shield, a common suffix for trilobite genera. Studies of Buenaspis have contributed to our understanding of trilobite evolution, early arthropod diversification, and the paleoecology of Cambrian marine environments. They provide insights into the conditions that led to the extraordinary preservation of soft tissues in the Sirius Passet Lagerstätte.