Cerebral Organization in the trilobite Yunnanocephalus yunnanensis
- 1King's College London
Abstract
The clade Trilobita is recognized for its extraordinary morphological diversifications amidst a highly constrained body plan. This raises the question of whether trilobite nervous systems were conservative or comparably diverse. However, despite the identification of thousands of trilobite species and increasing evidence for neural preservation in other Paleozoic euarthropods, the recognition of a fossilized trilobite brain has remained elusive. Here we describe the identification of a trilobite brain and its spatially constrained position within its cranidium. An unusually preserved specimen of the lower Cambrian trilobite Yunnanocephalus yunnanensis reveals a bilaterally organized organ connected to its lateral eyes. Comparisons to the brain of a trilobitomorph xandarellid support the interpretation of this organ as a modest cerebrum comprising prosocerebral, protocerebral, and deutocerebral domains, an organization typifying the euarthropod cerebral ground pattern. These findings suggest that the cerebrum of Yunnanocephalus could have supported the multimodal sensory processing and behavioral repertoires of trilobites, while retaining the deep evolutionary conservation of brain organization across euarthropod lineages
Related
- Within-Individual Organization of the Human Cerebral Cortex: Networks, Global Topography, and Function
- These legs were made for walking: 150 years of trilobite appendage morphology and evolution
- The trilobite nervous system and the early evolution of the mandibulate central complex
- Effects of Seedling Grade on Biomass Accumulation and Allometric Growth Across Developmental Stages in Pinus yunnanensis Franch. Seedlings.
- Effects of Ageratina adenophora invasion on soil multifunctionality and microbial networks of Pinus yunnanensis forest in the Panxi region, China
BibTeX
@misc{strausfeld2026cerebral,
title = {{Cerebral Organization in the trilobite Yunnanocephalus yunnanensis}},
author = {N. Strausfeld and F. Hirth},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.22.761110},
url = {https://www.biorxiv.org/content/10.64898/2026.10.22.761110v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Cerebral Organization in the trilobite Yunnanocephalus yunnanensis
AU - N. Strausfeld
AU - F. Hirth
PY - 2026
DA - 2026/10/22
PB - bioRxiv
DO - 10.64898/2026.10.22.761110
UR - https://www.biorxiv.org/content/10.64898/2026.10.22.761110v1
AB - The clade Trilobita is recognized for its extraordinary morphological diversifications amidst a highly constrained body plan. This raises the question of whether trilobite nervous systems were conservative or comparably diverse. However, despite the identification of thousands of trilobite species and increasing evidence for neural preservation in other Paleozoic euarthropods, the recognition of a fossilized trilobite brain has remained elusive. Here we describe the identification of a trilobite brain and its spatially constrained position within its cranidium. An unusually preserved specimen of the lower Cambrian trilobite Yunnanocephalus yunnanensis reveals a bilaterally organized organ connected to its lateral eyes. Comparisons to the brain of a trilobitomorph xandarellid support the interpretation of this organ as a modest cerebrum comprising prosocerebral, protocerebral, and deutocerebral domains, an organization typifying the euarthropod cerebral ground pattern. These findings suggest that the cerebrum of Yunnanocephalus could have supported the multimodal sensory processing and behavioral repertoires of trilobites, while retaining the deep evolutionary conservation of brain organization across euarthropod lineages
ER -