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El tallo osteichthyan Andreolepis y el origen del reemplazo dental
Donglei Chen1, Henning Blom1, Sophie Sanchez2,3
1Uppsala University, Department of Organismal Biology, Norbyvägen 18A, SE-752 36 Uppsala, Sweden.
Nature
|November 4, 2016
Resumen
Los vertebrados mandíbulas tienen diversos mecanismos de reemplazo de dientes. Un fósil de pez de 424 millones de años, Andreolepis hedei, muestra la pérdida temprana de dientes a través de la reabsorción, ofreciendo información sobre la evolución dental de los vertebrados.
Área de la Ciencia:
- Paleontología
- Biología evolutiva
- Zoología de los vertebrados
Sus antecedentes:
- Los patrones de reemplazo de dientes de gnatóstomos (vertebrados con mandíbula) son diversos y críticos para el mantenimiento de la dentición.
- Los mecanismos como las láminas dentales y el desprendimiento de dientes por resorción están distribuidos de manera desigual entre las especies existentes.
- Comprender el reemplazo dental primitivo es clave para rastrear la evolución dental de los vertebrados.
Objetivo del estudio:
- Para investigar el mecanismo de reemplazo de dientes en el antiguo osteichthyan, Andreolepis hedei.
- Para reconstruir la historia del crecimiento y el proceso de desprendimiento de los dientes de Andreolepis.
- Para determinar la ocurrencia más temprana de pérdida de dientes resortivos en los osteictianos.
Principales métodos:
- Sección virtual tridimensional mediante microtomografía sincrotrónica de propagación y contraste de fase.
- Análisis detallado de la estructura de la dentición de Andreolepis hedei.
- Reconstrucción del crecimiento dental y el historial de reemplazo.
Principales resultados:
- Andreolepis hedei, un osteictiano temprano, perdía dientes a través de la reabsorción de tejido duro basal.
- Este fósil probablemente carecía de una lámina dental permanente, lo que sugiere una vía de desarrollo diferente.
- Esto representa la evidencia documentada más antigua de pérdida de dientes por resorción.
Conclusiones:
- El derramamiento dental resortivo fue probablemente el modo primitivo de reemplazo dental en los osteictianos.
- Andreolepis hedei proporciona información crucial sobre la evolución temprana de la dentición de los vertebrados con mandíbula.
- Los hallazgos desafían las suposiciones anteriores sobre el estado ancestral de los mecanismos de reemplazo dental.
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