Sökning: onr:"swepub:oai:DiVA.org:uu-247264" >
Affnity, life cycle...
Affnity, life cycle, and intracellular complexity of organic-walled microfossils from the Mesoproterozoic of Shanxi, China
-
- Agić, Heda, 1989- (författare)
- Uppsala universitet,Paleobiologi,Palaeobiology
-
- Moczydłowska, Małgorzata (författare)
- Uppsala universitet,Paleobiologi
-
- Yin, Leiming (författare)
- Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences
-
(creator_code:org_t)
- 2015-03-09
- 2015
- Engelska.
-
Ingår i: Journal of Paleontology. - : Cambridge Journals. - 0022-3360 .- 1937-2337. ; 89:1, s. 28-50
- Relaterad länk:
-
https://www.cambridg...
-
visa fler...
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- Light microscope and scanning electron microscope observations on new material of unicellularmicrofossils Dictyosphaera macroreticulata and Shuiyousphaeridium macroreticulatum, from the MesoproterozoicRuyang Group in China, provide insights into the microorganisms’ biological affinity, life cycle and cellularcomplexity. Gigantosphaeridium fibratum n. gen. et sp., is described and is one of the largest Mesoproterozoicmicrofossils recorded. Phenotypic characters of vesicle ornamentation and excystment structures, properties ofresistance and cell wall structure in Dictyosphaera and Shuiyousphaeridium are all diagnostic of microalgalcysts. The wide size ranges of the various morphotypes indicate growth phases compatible with the development ofreproductive cysts. Conspecific biologically, each morphotype represents an asexual (resting cyst) or sexual (zygotic cyst)stage in the life cycle, respectively. We reconstruct this hypothetical life cycle and infer that the organism demonstrates areproductive strategy of alternation of heteromorphic generations. Similarly in Gigantosphaeridium, a metabolicallyexpensive vesicle with processes suggests its protective role as a zygotic cyst. In combination with all these charactersand from the resemblance to extant green algae, we propose the placement of these ancient microorganisms in the stemgroup of Chloroplastida (Viridiplantae). A cell wall composed of primary and secondary layers in Dictyosphaera andShuiyouisphaeridium required a high cellular complexity for their synthesis and the presence of an endomembranesystem and the Golgi apparatus. The plastid was also present, accepting the organism was photosynthetic. The biotareveals a high degree of morphological and cell structural complexity, and provides an insight into ongoing eukaryoticevolution and the development of complex life cycles with sexual reproduction by 1200Ma.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geology (hsv//eng)
Nyckelord
- organic-walled microfossils; early eukaryotes; Mesoproterozoic; Dictyosphaera; Shuiyousphaeridium; algae; evolution; intracellular complexity
- Earth Science with specialization in Historical Geology and Palaeontology
- Geovetenskap med inriktning mot historisk geologi och paleontologi
- Biologi med inriktning mot systematik
- Biology with specialization in Systematics
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas