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Una nueva hipótesis de las relaciones de los dinosaurios y la evolución temprana de los dinosaurios

Matthew G Baron^1,2, David B Norman¹, Paul M Barrett²

¹Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK.

|March 24, 2017

Resumen

Un nuevo árbol genealógico de dinosaurios sugiere que Ornithischia y Theropoda están estrechamente relacionados, formando el clado Ornithoscelida. Esto desafía los puntos de vista de larga data sobre la evolución temprana de los dinosaurios y requiere reclasificar los principales grupos de dinosaurios.

Área de la Ciencia:

Paleontología
Biología evolutiva
Estudio sistemático

Sus antecedentes:

Los dinosaurios han sido históricamente clasificados en dos clado principales: Ornithischia y Saurischia.
Esta clasificación tradicional ha sido el consenso durante 130 años.
Las definiciones cladísticas actuales presentan desafíos en la comprensión de la evolución temprana de los dinosaurios.

Objetivo del estudio:

Proponer una nueva hipótesis para las relaciones filogenéticas entre los principales grupos de dinosaurios.
Desafiar el consenso existente sobre la evolución de los dinosaurios.
Abordar los aspectos problemáticos de las definiciones cladísticas actuales.

Principales métodos:

Análisis filogenético de los principales grupos de dinosaurios.
Desarrollo de una nueva topología de árbol evolutivo.
Redefinición cladística y diagnóstico de los clado dinosaurios.

Principales resultados:

Se encontró una relación de grupo hermano entre Ornithischia y Theropoda, formando un nuevo clado: Ornithoscelida.
Sauropodomorpha y Herrerasauridae (redefinido Saurischia) forman el grupo externo monofilético de Ornithoscelida.
Esta nueva topología requiere reevaluaciones de la cladogénesis de los primeros dinosaurios y la evolución de los caracteres.

Conclusiones:

El clado Ornithoscelida propuesto desafía la clasificación tradicional de los dinosaurios.
Se sugiere la adquisición independiente de hipercarnívoros en herrerasaúridos y terópodos.
La nueva filogenia ofrece explicaciones para las convergencias anatómicas previamente notadas entre los terópodos y los primeros ornitisquios.

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