Life cycle of Early Ordovician acritarch species
2003 (English)Conference paper (Other (popular scientific, debate etc.))
Acritarchs are marine planktonic autotrophic protistans of heterogeneous origins. Their diversification into many morphotypes occurred throughout Neoproterozic and Early Palaeozoic; some morphotypes represent green algal classes but most are of unknown biological affinities. Palaeobiology and relationships to extant microbiota of some acritarchs, with emphasis on their life cycle, reproduction and environmental adaptations, may be inferred from phonetic morphological features and cell wall ultrastucture. Microfossils from the Cambrian-Ordovician of China are studied to reveal the wall ultrastructure of vegetative cells and dormant/reproductive cysts, the structural complexity of early eukaryotic cytoskeleton, and to recognize by morphological and ultrastructural means the relationships between various phenotypes. Acritarchs are considered to be preservable cysts of unicellular algae. The new discovery of the entire organism consisting of vegetative envelope and internal cyst shows that some taxa indeed represent the dormant/reproductive cysts whereas other may represent vegetative cells in their complex life cycle. Formation of the cyst, the excystment structure (pylome) and change of the generations (sexual and asexual) in the life cycle of unicellular microbiota may shed light on the development of the early adaptations to survive ecological crises events and as a competitive advantage in increasingly complex marine ecosystems.
Place, publisher, year, edition, pages
acritarch; life cycle; China
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-74332OAI: oai:DiVA.org:uu-74332DiVA: diva2:102242