Cambrian spiral-plated echinoderms from Gondwana reveal the earliest pentaradial body plan.
Proc Biol Sci
; 280(1765): 20131197, 2013 Aug 22.
Article
em En
| MEDLINE
| ID: mdl-23804624
ABSTRACT
Echinoderms are unique among animal phyla in having a pentaradial body plan, and their fossil record provides critical data on how this novel organization came about by revealing intermediate stages. Here, we report a spiral-plated animal from the early Cambrian of Morocco that is the most primitive pentaradial echinoderm yet discovered. It is intermediate between helicoplacoids (a bizarre group of spiral-bodied echinoderms) and crown-group pentaradiate echinoderms. By filling an important gap, this fossil reveals the common pattern that underpins the body plans of the two major echinoderm clades (pelmatozoans and eleutherozoans), showing that differential growth played an important role in their divergence. It also adds to the striking disparity of novel body plans appearing in the Cambrian explosion.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Evolução Molecular
/
Padronização Corporal
/
Equinodermos
/
Fósseis
Limite:
Animals
País/Região como assunto:
Africa
Idioma:
En
Revista:
Proc Biol Sci
Assunto da revista:
BIOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Reino Unido