Exceptionally well-preserved Cretaceous microfossils reveal new biomineralization styles.
Nat Commun
; 4: 2052, 2013.
Article
em En
| MEDLINE
| ID: mdl-23774480
ABSTRACT
Calcareous microplankton shells form the dominant components of ancient and modern pelagic sea-floor carbonates and are widely used in palaeoenvironmental reconstructions. The efficacy of these applications, however, is dependent upon minimal geochemical alteration during diagenesis, but these modifying processes are poorly understood. Here we report on new biomineralization architectures of previously unsuspected complexity in calcareous cell-wall coverings of extinct dinoflagellates (pithonellids) from a Tanzanian microfossil-lagerstätte. These Cretaceous 'calcispheres' have previously been considered biomineralogically unremarkable but our new observations show that the true nature of these tests has been masked by recrystallization. The pristine Tanzanian fossils are formed from fibre-like crystallites and show archeopyles and exquisitely constructed opercula, demonstrating the dinoflagellate affinity of pithonellids, which has long been uncertain. The interwoven fibre-like structures provide strength and flexibility enhancing the protective function of these tests. The low-density wall fabrics may represent specific adaptation for oceanic encystment life cycles, preventing the cells from rapid sinking.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Preservação Biológica
/
Dinoflagellida
/
Fósseis
/
Minerais
País/Região como assunto:
Africa
Idioma:
En
Revista:
Nat Commun
Assunto da revista:
BIOLOGIA
/
CIENCIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos