Inconsistencies in proposed annelid affinities of early biomineralized organism Cloudina (Ediacaran): structural and ontogenetic evidences

Vinn, Olev; Zatoń, Michał

doi:10.4267/2042/46095

Cited by 36 publications

(56 citation statements)

References 39 publications

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“…Tube morphology and microgranular ultrastructure ( fig. 5A) suggest that Cloudina is not closely related to any Recent calcareous polychaetes (serpulids, sabellids or cirratulids) (Vinn and Zatoń, 2012a). The type of asexual reproduction and presence of a closed tube base in Cloudina is more compatible with the hypothesis of an animal of cnidarian grade (Hua et al, 2005;Vinn and Zatoń, 2012a;Zhuravlev et al, 2012).…”

Section: False Serpulids: Tubular Fossils Below the Precambriancambrisupporting

confidence: 64%

Written in stone: history of serpulid polychaetes through time

et al. 2014

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Ippolitov, A.P., Vinn, O., Kupriyanova, E.K. and Jäger, M. 2014. Written in stone: history of serpulid polychaetes through time. Memoirs of Museum Victoria 71: 123-159.Although the fossil record of annelids in general is poor, calcareous tube-building Serpulidae are a notable exception. The "stumbling block" of understanding the serpulid fossil record is obtaining reliable taxonomic interpretations of fossil tubes based on morphology. Luckily, serpulid tubes demonstrate high variety of ultrastructures and nonuniform mineralogical composition, which can be used as new tools for decrypting the fossil record. Ancient Late Ediacaran (580-541 Ma) and Paleozoic (541-252 Ma) rocks contain diverse tubicolous fossils that have often been erroneously interpreted as annelids, and serpulids, in particular. Palaeozoic to Middle Jurassic coiled spirorbiform tubes, often referred to as Spirorbis, had been shown to be microconchids, a group of probable lophophorate affinity. The most ancient records of unequivocal serpulids date back to the Middle Triassic (~244 Ma) of the Mesozoic, and from the Earliest Jurassic (~200 Ma) fossil serpulids become common. From the latest Jurassic (~146 Ma) serpulids colonised hydrocarbon seep environments and possibly also penetrated the deep sea. Concerted efforts of paleontologists and zoologists are needed for further understanding of serpulid evolutionary history. The serpulid fossil record can become a valuable instrument for calibration of "molecular clocks" in polychaetes, which would allow dating not only divergence events in serpulids, but also in annelid groups that lack a representative fossil record.

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Section: False Serpulids: Tubular Fossils Below the Precambriancambrisupporting

confidence: 64%

Written in stone: history of serpulid polychaetes through time

et al. 2014

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“…Cloudina shows evidence for asexual reproduction including intercalar budding and longitudinal fission. These reproduction styles as well as rapid increase of the tube diameter, a closed apex, occasional tabulae and hexagonal symmetry of some species, are compatible with, but not conclusive of, a total group cnidarian and, therefore crown-eumetazoan affinity (19,20). Cloudina can show elevated growth of cemented and mutually-attached individuals to form substantial reef frameworks ( Figure 2C), and is also found re-worked to form concentrated 'shell' beds (22).…”

Section: Neoproterozoic-ediacaran Skeletal Taxamentioning

confidence: 92%

Exploring the drivers of early biomineralization

Wood

2018

Emerging Topics in Life Sciences

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points:  The first skeletons are known from protists, 810 Million years ago (Ma)  Large, putative metazoan, calcareous skeletons first appear in the terminal Ediacaran, ~550 Ma. Calcification was an independent and derived feature that appeared in diverse groups. The presence of a pre-existing organic scaffold, which provided the framework for interactions between extracellular matrix and mineral ions, can be inferred in many skeletal taxa. Calcareous biomineralization may have been favoured in the highly saturated, high alkalinity carbonate settings of the Ediacaran, where carbonate polymorph was further controlled by seawater chemistry. By the Early Cambrian, there is a marked increase in the diversity of skeletons as an escalating defensive response to increasing predation pressure, and biomineralization may have come under stronger biological control. The initial triggers for widespread biomineralization in the Ediacaran remain unclear. AbstractThe first biomineralised hard-parts are known from ~810 Million years ago (Ma), consisting of phosphatic plates of probable protists formed under active biological control. Large skeletons in diverse taxa, probably including total-group poriferans and total-group cnidarians, first appear in the terminal Ediacaran, ~550 Ma. This is followed by a substantial increase in abundance, diversity, and mineralogy during the early Cambrian. The biological relationship of Ediacaran to early Cambrian skeletal biota is unclear, but tubular skeletal fossils such as Cloudina and Anabarites straddle the transition. Many Ediacaran skeletal biota are found exclusively in carbonate settings, and present skeletons whose form infers an organic scaffold which provided the framework for interactions between extracellular matrix and mineral ions. Several taxa have close soft-bodied counterparts hosted in contemporary clastic rocks. This supports the assertion that the calcification was an independent and derived feature that appeared in diverse groups, that was initially acquired with minimal biological control in the highly saturated, high alkalinity carbonate settings of the Ediacaran, where carbonate polymorph was further controlled by seawater chemistry. The trigger for Ediacaran-Cambrian biomineralization is far from clear, but may have been either changing seawater Mg/Ca ratios that facilitated widespread aragonite and high-Mg calcite precipitation, and/or increasing or stabilising oxygen levels. By the Early Cambrian, the diversity of biomineralization styles may have been an escalating defensive response to increasing predation pressure, with skeletal hardparts first appearing in abundance in clastic settings by the Fortunian. This marks full independence from ambient seawater chemistry and significant biological control of biomineralization.

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“…Cloudina e Corumbella foram inseridos em Cnidaria (Grant, 1990;Babcock et al, 2005;Pacheco et al, 2011;Vinn & Zaton 2012;Wood et al, 2015) mas não se sabe a que filo pertenceria Namapoikia, Zhuravlev (2015) inseriu Namacalathus no Filo lophophorata com similaridade a Brachiopoda e Bryozoa no Superfilo Lophotrochozoa.Foram animais de pequeno tamanho não mais que alguns milímetros, 10 máximo de 19 mm para C. werneri (Pacheco et al, 2015) e de 8 a 150 mm para Cloudina hartmannae (Germs, 1972).…”

Section: Diversificação Dos Metazoários E Complexidade Dos Ecossistemasunclassified

“…Tais 2 organismos com exoesqueleto, alguns atribuídos ao Filo Cnidária (C. werneri e Cloldina spp.) (Grant, 1990, Pacheco et al, 2011, Vinn & Zaton 2012Wood, 2011, 2017, eram sésseis e já apresentavam uma nova dimensão fisiológica e etológica, capazes de predar e não apenas se alimentar como os filtradores, e possuíam simetria corporal distinta da anterior, com características de metazoários modernos. Este passo foi importante para o surgimento posteriormente na "Explosão Cambriana" (Conway Morris, 2000) de clados com grande número de espécies com novos modos de vida e capazes de ocupar ainda mais nichos ecológicos (Bambach et al, 2007).…”

Section: Introductionunclassified

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Análises estatísticas de Cloudina spp. no sul da faixa Paraguai e Namíbia. E suas implicações filogenéticas e evolutivas.

Strikis¹

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interpretado como possuindo corpo mole, segmentado que foi considerado como engenheiro de ecossistema pela sua forma de vida, infauna provavelmente se alimentava de tapetes bacterianos, ou também pelotas de fezes de organsmos infaunais. Microtomography led to the establishment of a new fossil organism or at least a dubiofossil at the end of Ediacaran period that has soft body and was segmented named Virgula itapucumense, that was considered an ecosystem engineer due to its life mode, infaunal and feeding in bacterial mat, or feces pellets of infaunal organisms.

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Inconsistencies in proposed annelid affinities of early biomineralized organism Cloudina (Ediacaran): structural and ontogenetic evidences

Cited by 36 publications

References 39 publications

Written in stone: history of serpulid polychaetes through time

Written in stone: history of serpulid polychaetes through time

Exploring the drivers of early biomineralization

Análises estatísticas de Cloudina spp. no sul da faixa Paraguai e Namíbia. E suas implicações filogenéticas e evolutivas.

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