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Células putativas de la cresta neural esquelética en vertebrados del ordenovicio temprano y tardío de Colorado
Science (New York, N.Y.)
|January 18, 1991
Resumen
Este estudio revela un vertebrado del Ordovícico con hueso celular y dentina, distinto de los exoesqueletos óseos acelulares previamente conocidos. Este hallazgo retrasa la línea de tiempo evolutiva de los tejidos esqueléticos celulares en los vertebrados.
Área de la Ciencia:
- Paleontología Paleontología.
- Evolución de los vertebrados Evolución de los vertebrados
- Histología esquelética Histología esquelética.
Sus antecedentes:
- El hueso y la dentina acelulares son conocidos en algunos vertebrados, propuestos como exoesqueletos primitivos.
- Estos tejidos se encuentran en los peces heterostrácidos.
Objetivo del estudio:
- Para caracterizar los tejidos esqueléticos de un vertebrado del Ordovícico recientemente identificado.
- Para comparar su exoesqueleto con las estructuras esqueléticas conocidas de vertebrados.
Principales métodos:
- Microscopía óptica de alta resolución de alta resolución.
- Microscopía electrónica de barrido con microscopía electrónica de barrido.
Principales resultados:
- Un tercer vertebrado posee un exoesqueleto distinto de denticulos con espacios celulares.
- Este tejido celular se asemeja más a los exoesqueletos osteostracanos que a los heterostracanos.
- El hueso celular y la dentina coexisten, lo que indica su origen antiguo.
Conclusiones:
- El hueso celular y la dentina son tan antiguos como el hueso acelular.
- Estos tejidos probablemente se originan en la cresta neural, homólogo a los dientes.
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