Live birth in an archosauromorph reptile.
Nat Commun
; 8: 14445, 2017 02 14.
Article
en En
| MEDLINE
| ID: mdl-28195584
ABSTRACT
Live birth has evolved many times independently in vertebrates, such as mammals and diverse groups of lizards and snakes. However, live birth is unknown in the major clade Archosauromorpha, a group that first evolved some 260 million years ago and is represented today by birds and crocodilians. Here we report the discovery of a pregnant long-necked marine reptile (Dinocephalosaurus) from the Middle Triassic (â¼245 million years ago) of southwest China showing live birth in archosauromorphs. Our discovery pushes back evidence of reproductive biology in the clade by roughly 50 million years, and shows that there is no fundamental reason that archosauromorphs could not achieve live birth. Our phylogenetic models indicate that Dinocephalosaurus determined the sex of their offspring by sex chromosomes rather than by environmental temperature like crocodilians. Our results provide crucial evidence for genotypic sex determination facilitating land-water transitions in amniotes.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Reptiles
/
Dinosaurios
/
Nacimiento Vivo
/
Evolución Biológica
Límite:
Animals
/
Pregnancy
País/Región como asunto:
Asia
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2017
Tipo del documento:
Article
País de afiliación:
China