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multicellular taxa

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Journal Article
Journal: Paleobiology
Published: 06 February 2017
Paleobiology (2017) 43 (2): 196-208.
... to operate in various multicellular taxa, thus providing a widely applicable explanation for the origin of latitudinal diversity gradients. Asymmetric range expansion is also apparent for the timing of invasion into adjacent regions. Species of planktonic foraminifera and calcareous...
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Journal Article
Journal: Paleobiology
Published: 01 August 2007
Paleobiology (2007) 33 (3): 351-381.
... loop at one end and opening with a slight divergence at the opposite end. The ridges are interpreted as casts of sediment-laden mucus strings formed by the movement of multicellular or syncytial organisms along a muddy surface. The taxa Myxomitodes stirlingensis n. igen., n. isp., are introduced...
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Journal Article
Journal: Paleobiology
Published: 01 February 2018
Paleobiology (2018) 44 (1): 40-57.
...Emily G. Mitchell; Nicholas J. Butterfield AbstractBedding-plane assemblages of Ediacaran fossils from Mistaken Point, Newfoundland, are among the oldest known records of complex multicellular life on Earth (dated to ~565 Ma). The in situ preservation of these sessile but otherwise deeply...
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Journal Article
Published: 01 July 2009
Journal of Paleontology (2009) 83 (4): 503-523.
... on the fossil record. The recognition of new taxa of exquisitely preserved rangeomorph fronds at Spaniard's Bay permits new insights into the paleobiology of this early experiment in multicellular development. A few specimens of Rangea from Namibia are surrounded by a thin, structureless, commonly wrinkled...
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Journal Article
Journal: Paleobiology
Published: 01 January 2005
Paleobiology (2005) 31 (2_Suppl): 94-112.
... that he reiterated for the next 13 years. These ideas set the agenda for much subsequent research. Since 1989 cladistic analyses have accommodated most of the problematic Cambrian taxa as stem groups of living taxa. Morphological disparity has been shown to be similar in Cambrian times as now. Konservat...
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Journal Article
Journal: Geology
Published: 19 October 2017
Geology (2017) 45 (12): 1079-1082.
... assemblage. Eight genera include the second occurrence of the putative multicellular fossil animal embryo Megasphaera outside South China, the Doushantuo-Pertatataka–type acanthomorphic acritarchs h Cavaspina, and Variomargosphaeridium, and the possible alga Archaeophycus yunnanensis. The assemblage occurs...
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Journal Article
Published: 22 December 2016
Journal of Paleontology (2016) 91 (2): 199-229.
...., Symplassosphaeridium spp., and a large compartmentalized multicellular form—unnamed form A), and two filamentous taxa ( Tortunema sp. and unnamed form F). Some of the Roper colonial and filamentous microfossils are interpreted as probable cyanobacteria because of both their occurrence...
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Journal Article
Published: 01 March 2002
Journal of Paleontology (2002) 76 (2): 347-376.
... a taphonomically-controlled comparison of the two assemblages. As detailed in the systematic paleontology section, the macroscopic compression biota at Miaohe comprises some twenty distinct taxa, most of them multicellular algae ( Table 1 ). Miaohe compressions preserve morphological characters such as holdfasts...
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Journal Article
Journal: Paleobiology
Published: 01 January 2002
Paleobiology (2002) 28 (1): 41-54.
... as an epifaunal clamping animal, and slow growth (low expansion rates) and metabolism. Further compartmentalization, together with increased metabolic rates in ecologically dominant taxa, caused the morphospace to expand both in the number of independent descriptors and in the range of values that each parameter...
Journal Article
Journal: Paleobiology
Published: 01 January 2002
Paleobiology (2002) 28 (3): 308-327.
... of the demonstration, we also show how results can be transformed into a quantitative estimate of an upper limit on bias. Finally, we place the question of bias in a larger context, arguing that the same criteria and methods we employ here can be used to test for bias in other colonial taxa, and also at other...
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Journal Article
Published: 01 March 2001
Journal of Paleontology (2001) 75 (2): 427-448.
... microbiota are shown in Fig. 3 ). In addition to these common Proterozoic taxa, the Burovaya microbiota contains rare remnants of multicellular trichomes and some microfossils of ellipsoidal morphology. Among the multicellular trichomes the most abundant are Oscillatoriopsis obtusa Schopf, 1968...
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Series: GSA Special Papers
Published: 01 January 1970
DOI: 10.1130/SPE127-p247
.... Evolutionary rates in protists are comparable to those of multicellular organisms, although attainment of variability, isolation mechanisms, and selection processes differ. The apparent exponential increase of phytoplankton taxa at successive periods in their geologic history is related to their mutation-based...
Journal Article
Journal: Geology
Published: 01 January 2017
Geology (2017) 45 (1): 75-78.
... organisms in the Tonian Period, thus enriching our knowledge about the multiple origins of multicellularity in this critical geological period before Cryogenian glaciations. One may choose to name the naked aggregates, enveloped aggregates, and Chuaria vesicles as distinct taxa. However, based...
Journal Article
Published: 01 March 2014
Journal of Paleontology (2014) 88 (2): 263-268.
..., 1961 ). Unlike Halimeda , Ovulites , Paleoporella and the other limestone-building codiaceans, Elainabella is not calcified, but calcification is an ephemeral trait within this family; most extant codiacean taxa are not calcified ( Johnson, 1961 ). Other Proterozoic multicellular algae with which...
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Journal Article
Journal: Paleobiology
Published: 01 January 2000
Paleobiology (2000) 26 (3): 386-404.
... formation shows Bangiomorpha pubescens to have been sexually reproducing, the oldest reported occurrence in the fossil record. Sex was critical for the subsequent success of eukaryotes, not so much for the advantages of genetic recombination, but because it allowed for complex multicellularity...
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Journal Article
Journal: Paleobiology
Published: 01 May 2007
Paleobiology (2007) 33 (2): 182-200.
... eukaryotic cell, the aggregation of single eukaryotic cells to form complex multicellular organisms, and finally, the association of multicellular organisms to form complex colonial individuals. These transitions together constitute one of the most salient and certain trends in the history of life...
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Journal Article
Journal: Paleobiology
Published: 01 January 2001
Paleobiology (2001) 27 (2): 405-423.
... of prokaryotic cells, of multicellular organisms from clones of eukaryotic cells, and of integrated colonies from aggregates of multicellular individuals. Arranged in order of first occurrence, these three transitions suggest a trend, in particular a trend in the maximum, or an increase in the degree...
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Journal Article
Published: 01 September 2005
Journal of Paleontology (2005) 79 (5): 1040-1042.
... the basic scientific substance of this book in chapter 2, “Palaeobiology of the Doushantuo Formation.” This long chapter begins with a review of the research history and a summary of the geology and biostratigraphy of the major fossil sites; it then presents a systematic survey of the well-preserved taxa...
Journal Article
Journal: Paleobiology
Published: 01 January 2001
Paleobiology (2001) 27 (2): 327-347.
.... The cleavage model for gastropods obviously does not explain coiling asymmetries in unicellular foraminifera. Still, Freeman and Lundelius's model for how the cytoskeleton is affected by a cytoplasmic product for dextrality is quite attractive since both unicellular and multicellular taxa use actin-based...
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Journal Article
Published: 03 May 2017
Journal of the Geological Society (2017) 174 (5): 793-802.
... the Weng'an Biota includes forms that could be animals, none can currently be assigned to this group with confidence. Nonetheless, the biota offers a rare and valuable window on the evolution of multicellular and soft-bodied organisms in the prelude to the Cambrian radiation. The acritarchs ( Fig. 2k ) from...
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