Evaluation of Groundwater Resource in Huaian Region of Jiangsu Province, China

Chen, Gongxin; Liu, Jinhui

doi:10.1109/esiat.2009.438

Cited by 6 publications

(12 citation statements)

References 2 publications

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“…sinica Represents a Stem-Group Cnidarian. X. sinica has been alternatively interpreted as a crown-group cnidarian (16,(19)(20)(21)(22), a ctenophore (23,26), a lophophorate (27), or a survivor of vendobionts (28). We have shown here that X. sinica had a relatively simple anatomy with a radial symmetry, a polypoid body, and a blind gut containing septum-like structures.…”

Section: Significancementioning

confidence: 76%

“…The polypoid body shape of X. sinica has led some authors to assume that it might represent an early lineage of crown cnidarians, with previous reconstructions resembling a modern sea anemone (21)(22)(23)(24). However, the feather-like architecture of tentacles described herein is unknown from extant actiniarians or possible Cambrian cnidarian candidates such as Eolympia pediculata (28), Archisaccophyllia kunmingensis (29), Thaumaptilon walcotti (53), Mackenzia costalis (53), and Echmatocrinus brachiatus (54).…”

Section: Significancementioning

confidence: 99%

“…These putative species have been assigned to three different animal groups: hexacorals (16,(19)(20)(21)(22)(23)(24), octocorals (17,25), and hemichordates (18), respectively. However, alternative views suggest that X. sinica was a ctenophore (23, 26), a lophophorate (27), an Ediacaran survivor (28), or a metazoan of unknown affinity (29,30).…”

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confidence: 99%

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

Han

Zhang

et al. 2017

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

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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

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Section: Significancementioning

confidence: 76%

Section: Significancementioning

confidence: 99%

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

Han

Zhang

et al. 2017

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

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“…In our view, the most compelling observation revolves around the arrangement of the anterior unit and especially the longitudinal grooves, which we propose played a key role. While evidently having the same composition as the rest of the anterior body wall, the grooves appear to have been more flexible [28]. This is particularly evident from the range of configurations that vary from specimens where the groove is effectively closed (Figure 4A) to others where either margin is widely separated (Additional file 1).…”

Section: Resultsmentioning

confidence: 99%

“…The crux of the problem revolves around the nature of prominent lateral structures, but to date there is neither agreement as to their original configuration nor function. Identifications range from midgut glands [27] to respiratory organs, but in the latter case interpretations are as disparate as a direct comparison to crustacean branchial chambers [12,20,21,28] as against pharyngeal gill slits [13,16,17,24]. Resolution of this divergence of interpretations would be possible if exquisitely preserved material were available that would allow not only a complete anatomical description but one that can be combined with a plausible functional analysis.…”

Section: Introductionmentioning

confidence: 99%

Evidence for gill slits and a pharynx in Cambrian vetulicolians: implications for the early evolution of deuterostomes

Morris

Han

et al. 2012

BMC Biol

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BackgroundVetulicolians are a group of Cambrian metazoans whose distinctive bodyplan continues to present a major phylogenetic challenge. Thus, we see vetulicolians assigned to groups as disparate as deuterostomes and ecdysozoans. This divergence of opinions revolves around a strikingly arthropod-like body, but one that also bears complex lateral structures on its anterior section interpreted as pharyngeal openings. Establishing the homology of these structures is central to resolving where vetulicolians sit in metazoan phylogeny.ResultsNew material from the Chengjiang Lagerstätte helps to resolve this issue. Here, we demonstrate that these controversial structures comprise grooves with a series of openings. The latter are oval in shape and associated with a complex anatomy consistent with control of their opening and closure. Remains of what we interpret to be a musculature, combined with the capacity for the grooves to contract, indicate vetulicolians possessed a pumping mechanism that could process considerable volumes of seawater. Our observations suggest that food captured in the anterior cavity was transported to dorsal and ventral gutters, which then channeled material to the intestine. This arrangement appears to find no counterpart in any known fossil or extant arthropod (or any other ecdysozoan). Anterior lateral perforations, however, are diagnostic of deuterostomes.ConclusionsIf the evidence is against vetulicolians belonging to one or other group of ecdysozoan, then two phylogenetic options seem to remain. The first is that such features as vetulicolians possess are indicative of either a position among the bilaterians or deuterostomes but apart from the observation that they themselves form a distinctive and recognizable clade current evidence can permit no greater precision as to their phylogenetic placement. We argue that this is too pessimistic a view, and conclude that evidence points towards vetulicolians being members of the stem-group deuterostomes; a group best known as the chordates (amphioxus, tunicates, vertebrates), but also including the ambulacrarians (echinoderms, hemichordates), and xenoturbellids. If the latter, first they demonstrate that these members of the stem group show few similarities to the descendant crown group representatives. Second, of the key innovations that underpinned deuterostome success, the earliest and arguably most seminal was the evolution of openings that define the pharyngeal gill slits of hemichordates (and some extinct echinoderms) and chordates.

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Symbiotic fouling of Vetulicola, an early Cambrian nektonic animal

Williams

Harvey

et al. 2020

Commun Biol

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Here, we report the earliest fossil record to our knowledge of surface fouling by aggregates of small vermiform, encrusting and annulated tubular organisms associated with a mobile, nektonic host, the enigmatic Cambrian animal Vetulicola. Our material is from the exceptionally preserved early Cambrian (Epoch 2, Age 3), Chengjiang biota of Yunnan Province, southwest China, a circa 518 million-year old marine deposit. Our data show that symbiotic fouling relationships between species formed a component of the diversification of animal-rich ecosystems near the beginning of the Phanerozoic Eon, suggesting an early escalation of intimate ecologies as part of the Cambrian animal radiation.

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Evaluation of Groundwater Resource in Huaian Region of Jiangsu Province, China

Cited by 6 publications

References 2 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

Evidence for gill slits and a pharynx in Cambrian vetulicolians: implications for the early evolution of deuterostomes

Symbiotic fouling of Vetulicola, an early Cambrian nektonic animal

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