OBJECT DOSSIER · SMITHSONIAN OPEN ACCESS

Trilobite — Ceraurus pleurexanthemus

SAGE Museum Deep Time scientific dossier

Date / Period

Ordovician · Ordovician; exact age of this individual display fossil is not assigned here.

Object Type

exoskeleton fossil

Medium

representative_scientific_visual

About This Object

Geologic period: Ordovician

Age: Ordovician; exact age of this individual display fossil is not assigned here.

Feeding: Diet is not directly preserved by this display fossil.

Locomotion: Exceptional Ceraurus material elsewhere preserves paired biramous appendages used for movement.

Body plan: Armored arthropod body with cephalon, segmented thorax, pygidium and defensive-looking spines.

Evidence: Shell anatomy is direct evidence. Knowledge of limbs comes from exceptionally preserved members of the same species.

Why it matters: Rare three-dimensional Ceraurus fossils help scientists study appendages normally hidden beneath trilobite shells.

Plain Language Identity: A spiny Ordovician trilobite.

What You Are Looking At: A segmented trilobite exoskeleton with prominent spines.

Ecosystem: Ordovician marine ecosystem.

Preservation: Mineralized arthropod exoskeleton.

Open Questions: Do not imply that hidden soft anatomy is visible in every specimen.

Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://www.sciencedirect.com/science/article/abs/pii/S1467803924000410

Enrichment Method: SAGE curated research pass; title and scientific name matched; evidence separated from inference

Scientific name: Ceraurus pleurexanthemus

Evidence / representation: Representative evidence-type visual; not the exact specimen.

Why It Is In This SAGE Exhibit

Representative evidence-type visual; not the exact specimen.

Oceans Before Dinosaurs: The Rise of Complex Animal Life.

Provenance

Smithsonian Deep Time source scene: Early Life in the Ocean

Exhibition History

Included in the SAGE Museum Dinosaurs & Deep Time staging exhibit.

Subjects & Themes

Ceraurus pleurexanthemus Ordovician exoskeleton fossil Early Life in the Ocean Oceans Before Dinosaurs

ORIGINAL COLLECTION SOURCE

This object page stays inside SAGE Museum. The Smithsonian link below is provided only as the original scholarly collection record. It opens separately.