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El Protomelission es un alga dasiclada temprana y no un bryozoan del Cámbrico
Jie Yang1, Tian Lan2, Xi-Guang Zhang3
1Institute of Palaeontology, Yunnan University, Chenggong, Kunming, China.
Nature
|March 8, 2023
Resumen
Los primeros fósiles de animales del Cámbrico, que anteriormente se pensaba que eran el filo de los animales de musgo (Bryozoa), ahora se identifican como algas verdes. Esta reclasificación significa que el Bryozoa definitivo de la era Cámbrica permanece sin descubrir.
Área de la Ciencia:
- Paleontología
- Biología evolutiva
- Biología marina
Sus antecedentes:
- Los phyla animales y los planos corporales se originaron durante la explosión cámbrica hace más de 500 millones de años.
- El filo Bryozoa (animales de musgo) ha carecido de evidencia clara de fósiles del Cámbrico debido a las dificultades para distinguir sus esqueletos.
- La protomelisión, un microfósil fosfático, se consideró el candidato más fuerte para un bryozoan temprano.
Objetivo del estudio:
- Para reevaluar la clasificación del fósil Protomelission.
- Investigar los orígenes del plan corporal de los Briozoos en las primeras comunidades del Cámbrico.
Principales métodos:
- Análisis de la anatomía no mineralizada excepcionalmente conservada en macrofósiles similares a la Protomelisión.
- Examen detallado de la estructura del esqueleto.
- Análisis tafonómico para comprender los procesos de fosilización.
Principales resultados:
- Los fósiles de protomelisión exhiben una anatomía no mineralizada inconsistente con los Bryozoa.
- Las características esqueléticas y las "aperturas zoóides" se reinterpretan como estructuras de algas.
- La protomelisión se identifica como la más antigua de las algas verdes dasicladales conocidas.
Conclusiones:
- La protomelisión representa un fotosintetizador bentónico temprano, no un bryozoario temprano.
- Los orígenes del plan corporal de los briozoos no están claros desde el período Cámbrico.
- Todavía no se han encontrado bryozoos inequívocos de la era Cámbrica.
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