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La anatomía del cerebro del fósil del Cámbrico Jianfengia multisegmentalis informa sobre la filogenia de los
Nicholas J Strausfeld1, David R Andrew2, Xianguang Hou3
1Department of Neuroscience, University of Arizona, Tucson, AZ, 85721, USA. flybrain@arizona.edu.
Nature communications
|August 28, 2025
Resumen
Los primeros euartrópodos del Cámbrico, como Jianfengia multisegmentalis, muestran rasgos neuronales cruciales. Estos hallazgos aclaran las relaciones evolutivas dentro de Euarthropoda, particularmente los orígenes de Mandibulata y Chelicerata.
Área de la Ciencia:
- Paleontología
- Biología evolutiva
- La neuroanatomía
Sus antecedentes:
- La biota de Chengjiang muestra a los primeros euartrópodos que coexistieron con grupos de coronas reconocibles hace más de 500 millones de años.
- Estudios anteriores identificaron a Fuxianhuia protensa y Alalcomenaeus como mandibulados del tallo y quelicerados del tallo, respectivamente, basados en rasgos cerebrales y ganglionares.
Objetivo del estudio:
- Para investigar los sistemas visuales y el cerebro de Jianfengia multisegmentalis, un enigmático euartrópodos del Bajo Cámbrico.
- Determinar la posición filogenética de Jianfengia y sus implicaciones para la evolución temprana de los euartrópodos, particularmente con respecto a la morfología del "gran apéndice".
Principales métodos:
- Análisis neuroanatómico de Jianfengia multisegmentalis, centrado en las neuropilas ópticas, los ocelos rostrales y las vías neuronales asociadas.
- Análisis filogenéticos que incorporan rasgos neuronales de Jianfengia, otros taxones del Cámbrico y Euarthropoda existentes.
Principales resultados:
- Jianfengia multisegmentalis exhibe rasgos neuronales, incluidas tres neuropilas ópticas anidadas y ocelos rostrales, sugestivos de Pancrustacea.
- Los análisis filogenéticos colocan a Jianfengia como hermana del total de Mandibulata y Leanchoiliidae (un taxón de "gran apéndice") como hermana del total de Chelicerata.
- El estudio proporciona evidencia de que la morfología del "gran apéndice" caracteriza el tallo temprano que conduce a los principales linajes de euartrópodos.
Conclusiones:
- Los datos neuroanatómicos de fósiles del Cámbrico como Jianfengia son herramientas poderosas para resolver las relaciones de los euartrópodos.
- Los hallazgos apoyan una hipótesis de larga data con respecto a la importancia de la morfología del "gran apéndice" en la diversificación temprana de los euartrópodos.
- La neuroanatomía de Jianfengia proporciona información sobre la divergencia basal de los principales clados de euartrópodos.
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