A vanished history of skeletonization in Cambrian comb jellies

Ou, Qiang; Xiao, Shuhai; Han, Jian; Sun, Ge; Zhang, Fang; Zhang, Zhifei; Shu, Degan

doi:10.1126/sciadv.1500092

Cited by 32 publications

(37 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An assignment of X. sinica to Ctenophora was based on the putative resemblance of the longitudinal ridges on the column to the comb rows of ctenophores (23,26). However, the radial rather than biradial body symmetry and the presence of featherlike tentacles, septum-like structures, and a holdfast in X. sinica are inconsistent with the anatomy of fossil (4,50) and extant ctenophores (e.g., ref. 51).…”

Section: Significancementioning

confidence: 96%

Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity

Han

Zhang

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The early Cambrian problematica Xianguangia sinica, Chengjiangopenna wangii, and Galeaplumosus abilus from the Chengjiang biota (Yunnan, China) have caused much controversy in the past and their phylogenetic placements remain unresolved. Here we show, based on exceptionally preserved material (85 new specimens plus type material), that specimens previously assigned to these three species are in fact parts of the same organism and propose that C. wangii and G. abilus are junior synonyms of X. sinica. Our reconstruction of the complete animal reveals an extinct body plan that combines the characteristics of the three described species and is distinct from all known fossil and living taxa. This animal resembled a cnidarian polyp in overall morphology and having a gastric cavity partitioned by septum-like structures. However, it possessed an additional body cavity within its holdfast, an anchoring pit on the basal disk, and feather-like tentacles with densely ciliated pinnules arranged in an alternating pattern, indicating that it was a suspension feeder rather than a predatory actiniarian. Phylogenetic analyses using Bayesian inference and maximum parsimony suggest that X. sinica is a stemgroup cnidarian. This relationship implies that the last common ancestor of X. sinica and crown cnidarians was probably a benthic, polypoid animal with a partitioned gastric cavity and a single mouth/anus opening. This extinct body plan suggests that feeding strategies of stem cnidarians may have been drastically different from that of their crown relatives, which are almost exclusively predators, and reveals that the morphological disparity of totalgroup Cnidaria is greater than previously assumed.Xianguangia sinica | Chengjiangopenna wangii | Galeaplumosus abilus | ciliary suspension feeder | cnidarian stem group

show abstract

Section: Significancementioning

confidence: 96%

Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity

Han

Zhang

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…They use eight external comb rows (ctenes) for locomotion, these being densely packed with cilia up to 2 mm long, the largest known cilia among animals [1]. Despite the fact that ctenophores are unequivocally monophyletic and have a diverse Cambrian fossil record [2,3], their origin and place in animal phylogeny have been difficult to resolve [4][5][6]. Ctenophores and cnidarians share diploblasty (two germ layers separated by mesoglea), a large digestive cavity (coelenteron), and radial or biradial symmetry.…”

Section: Introductionmentioning

confidence: 99%

“…The oldest unequivocal ctenophore fossils are found in the early Cambrian Chengjiang Konservat-Lagerst€ atte [2,[29][30][31] and middle Cambrian Burgess Shale [3], demonstrating that general features of ctenophores, such as ctene or comb rows and a globose body shape, have ancient origins. Younger taxa are known from the Ordovician [32] and the Devonian [33,34].…”

Section: Introductionmentioning

confidence: 99%

Cambrian Sessile, Suspension Feeding Stem-Group Ctenophores and Evolution of the Comb Jelly Body Plan

et al. 2019

View full text Add to dashboard Cite

show abstract

“…) and equally labile structures such as ctenophore ctens (Ou et al . ) are not beyond the realm of taphonomic possibility. Still, the remarkable preservation of tentacle‐like structures in Lantianella intrigued Van Iten et al .…”

Section: Systematic Palaeontologymentioning

confidence: 99%

Systematic description of putative animal fossils from the early Ediacaran Lantian Formation of South China

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract:The early Ediacaran Lantian Formation in South China contains some of the oldest known representatives of morphologically complex macroorganisms, including various macroalgae and putative animals. The macroalgal fossils have been described previously in several publications, but no taxonomic treatment has been published for the putative animal fossils. This hampers our ability to fully evaluate and communicate the significance of these potentially important Ediacaran macrofossils. To address this deficiency, here we provide a systematic description of these putative animal fossils from the Lantian Formation, including four new genera and five new species: Lantianella laevis gen. et sp. nov., L. annularis gen. et sp. nov., Piyuania cyathiformis gen. et sp. nov., Qianchuania fusiformis gen. et sp. nov. and Xiuningella rara gen. et sp. nov. Morphological comparisons of these fossils and potential modern analogues are provided and critically assessed.

show abstract

A vanished history of skeletonization in Cambrian comb jellies

Abstract: Early evolution of the basal animal phylum illuminated by sclerotized and armored ctenophore species from early Cambrian period.

Cited by 32 publications

References 41 publications

Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity

Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity

Cambrian Sessile, Suspension Feeding Stem-Group Ctenophores and Evolution of the Comb Jelly Body Plan

Systematic description of putative animal fossils from the early Ediacaran Lantian Formation of South China

Contact Info

Product

Resources

About