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Yang X, Aguado MT, Helm C, Zhang Z, Bleidorn C. New fossil of Gaoloufangchaeta advances the origin of Errantia (Annelida) to the early Cambrian. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231580. [PMID: 38601033 PMCID: PMC11004674 DOI: 10.1098/rsos.231580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 04/12/2024]
Abstract
Molecular clock estimates suggest the origin of Annelida dates back to the Ediacaran period, which is in discordance with the first appearance of this taxon in the early Cambrian, as evidenced by the fossil records of stem-group and basally branching crown-group annelids. Using new material from the early Cambrian Guanshan biota (Cambrian Series 2, Stage 4), we re-interpret Gaoloufangchaeta bifurcus Zhao, Li & Selden, 2023, as the earliest known errantian annelid. Gaoloufangchaeta has a prominent anterior end bearing three pairs of putatively sensory appendages and a pair of anterior eyes; a muscular eversible pharynx with papillae is identified. The presence of enlarged parapodia with acicula-like structures and long capillary chaetae suggests a pelagic lifestyle for this taxon. Our phylogenetic analyses recover Gaoloufangchaeta within the Phyllodocida (Pleistoannelida, Errantia), extending the origin of Errantia back to the early Cambrian. Our data are in line with the hypothesis that Annelida diverged before the Cambrian and indicate both morphological and ecological diversification of annelids in the early Cambrian.
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Affiliation(s)
- Xiaoyu Yang
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming650500, People's Republic of China
- Animal Evolution and Biodiversity, Georg-August-Universität Göttingen, Göttingen37073, Germany
| | - M. Teresa Aguado
- Animal Evolution and Biodiversity, Georg-August-Universität Göttingen, Göttingen37073, Germany
| | - Conrad Helm
- Animal Evolution and Biodiversity, Georg-August-Universität Göttingen, Göttingen37073, Germany
| | - Zhiqian Zhang
- School of Fine Arts, Yunnan Normal University, Kunming650500, People's Republic of China
| | - Christoph Bleidorn
- Animal Evolution and Biodiversity, Georg-August-Universität Göttingen, Göttingen37073, Germany
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2
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Kimmig J, LaVine RJ, Schiffbauer JD, Egenhoff SO, Shelton KL, Leibach WW. Annelids from the Cambrian (Wuliuan Stage, Miaolingian) Spence Shale Lagerstätte of northern Utah, USA. HISTORICAL BIOLOGY 2023; 36:934-943. [PMID: 38800616 PMCID: PMC11114447 DOI: 10.1080/08912963.2023.2196685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/22/2023] [Indexed: 05/29/2024]
Abstract
The Spence Shale Member of the Langston Formation in northern Utah and southern Idaho preserves generally non-biomineralized fossil assemblages referred to as the Spence Shale Lagerstätte. The biota of this Lagerstätte is dominated by panarthropods, both biomineralized and soft-bodied examples, but also preserves diverse infaunal organisms, including species of scalidophorans, echinoderms, lobopodians, stalked filter feeders, and various problematic taxa. To date, however, only a single annelid fossil, originally assigned to Canadia sp., has been described from the Spence Shale. This lone specimen and another recently collected specimen were analyzed in this study using scanning electron microscopy and energy dispersive X-ray spectrometry. The previous occurrence is reassigned to Burgessochaeta cf. B. setigera Walcott, 1911. The new fossil, however, is identified as a novel polychaete taxon, Shaihuludia shurikeni gen. et sp. nov., characterized by the presence of fused, bladed chaetae and a wide body. The occurrence of Burgessochaeta is the first outside the Burgess Shale and its vicinity, whereas Shaihuludia shurikeni gen. et sp. nov. adds to the diversity of annelids in the middle Cambrian and highlights the diversity of the Spence Shale Lagerstätte.
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Affiliation(s)
- Julien Kimmig
- Abteilung Geowissenschaften, Staatliches Museum für Naturkunde Karlsruhe, Karlsruhe, 76133, Germany
- The Harold Hamm School of Geology & Geological Engineering, University of North Dakota, Grand Forks, ND 58202, USA
| | - Rhiannon J. LaVine
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA
| | - James D. Schiffbauer
- Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA
- X-ray Microanalysis Laboratory, University of Missouri, Columbia, MO 65211, USA
| | - Sven O. Egenhoff
- The Harold Hamm School of Geology & Geological Engineering, University of North Dakota, Grand Forks, ND 58202, USA
| | - Kevin L. Shelton
- Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Wade W. Leibach
- Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA
- Jacobs Solutions, St. Louis, MO 63102, USA
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3
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Osawa H, Caron JB, Gaines RR. First record of growth patterns in a Cambrian annelid. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221400. [PMID: 37122950 PMCID: PMC10130728 DOI: 10.1098/rsos.221400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
Early annelid evolution is mostly known from 13 described species from Cambrian Burgess Shale-type Lagerstätten. We introduce a new exceptionally well-preserved polychaete, Ursactis comosa gen. et sp. nov., from the Burgess Shale (Wuliuan Stage). This small species (3-15 mm) is the most abundant Cambrian polychaete known to date. Most specimens come from Tokumm Creek, a new Burgess Shale locality in northern Kootenay National Park, British Columbia, Canada. Ursactis has a pair of large palps, thin peristomial neurochaetae and biramous parapodia bearing similarly sized capillary neurochaetae and notochaetae, except for segments six to nine, which also have longer notochaetae. The number of segments in this polychaete range between 8 and 10 with larger individuals having 10 segments. This number of segments in Ursactis is remarkably small compared with other polychaetes, including modern forms. Specimens with 10 segments show significant size variations, and the length of each segment increases with the body length, indicating that body growth was primarily achieved by increasing the size of existing segments rather than adding new ones. This contrasts with most modern polychaetes, which typically have a larger number of segments through additions of segments throughout life. The inferred growth pattern in Ursactis suggests that annelids had evolved control over segment addition by the mid-Cambrian.
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Affiliation(s)
- Hatena Osawa
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
- Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada M5S 2C6
| | - Jean-Bernard Caron
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
- Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada M5S 2C6
- Department of Earth Sciences, University of Toronto, 22 Ursula Franklin Street, Toronto, Ontario, Canada M5S 3B1
| | - Robert R. Gaines
- Geology Department, Pomona College, 185 E Sixth Street, Claremont, CA 91711, USA
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Saleh F, Ma X, Guenser P, Mángano MG, Buatois LA, Antcliffe JB. Probability-based preservational variations within the early Cambrian Chengjiang biota (China). PeerJ 2022; 10:e13869. [PMID: 36032952 PMCID: PMC9415357 DOI: 10.7717/peerj.13869] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/19/2022] [Indexed: 01/18/2023] Open
Abstract
The Chengjiang biota (Yunnan Province, China) is a treasure trove of soft-bodied animal fossils from the earliest stages of the Cambrian explosion. The mechanisms contributing to its unique preservation, known as the Burgess Shale-type preservation, are well understood. However, little is known about the preservation differences between various animal groups within this biota. This study compares tissue-occurrence data of 11 major animal groups in the Chengjiang biota using a probabilistic methodology. The fossil-based data from this study is compared to previous decay experiments. This shows that all groups are not equally preserved with some higher taxa more likely to preserve soft tissues than others. These differences in fossil preservation between taxa can be explained by the interaction of biological and environmental characteristics. A bias also results from differential taxonomic recognition, as some taxa are easily recognized from even poorly preserved fragments while other specimens are difficult to assign to higher taxa even with exquisite preservation.
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Affiliation(s)
- Farid Saleh
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China,Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China
| | - Xiaoya Ma
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China,Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China,Centre for Ecology and Conservation, University of Exeter, Penryn, United Kingdom
| | - Pauline Guenser
- University Bordeaux, CNRS, Bordeaux INP, EPOC, UMR5805, Pessac, France
| | - M. Gabriela Mángano
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Luis A. Buatois
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada
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Maria Costa-Paiva E, Mello B, Santos Bezerra B, Coates CJ, Halanych KM, Brown F, de Moraes Leme J, Trindade RIF. Molecular dating of the blood pigment hemocyanin provides new insight into the origin of animals. GEOBIOLOGY 2022; 20:333-345. [PMID: 34766436 DOI: 10.1111/gbi.12481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 10/14/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
The Neoproterozoic included changes in oceanic redox conditions, the configuration of continents and climate, extreme ice ages (Sturtian and Marinoan), and the rise of complex life forms. A much-debated topic in geobiology concerns the influence of atmospheric oxygenation on Earth and the origin and diversification of animal lineages, with the most widely popularized hypotheses relying on causal links between oxygen levels and the rise of animals. The vast majority of extant animals use aerobic metabolism for growth and homeostasis; hence, the binding and transportation of oxygen represent a vital physiological task. Considering the blood pigment hemocyanin (Hc) is present in sponges and ctenophores, and likely to be present in the common ancestor of animals, we investigated the evolution and date of Hc emergence using bioinformatics approaches on both transcriptomic and genomic data. Bayesian molecular dating suggested that the ancestral animal Hc gene arose approximately 881 Ma during the Tonian Period (1000-720 Ma), prior to the extreme glaciation events of the Cryogenian Period (720-635 Ma). This result is corroborated by a recently discovered fossil of a putative sponge ~890 Ma and modern molecular dating for the origin of metazoans of ~1,000-650 Ma (but does contradict previous inferences regarding the origin of Hc ~700-600 Ma). Our data reveal that crown-group animals already possessed hemocyanin-like blood pigments, which may have enhanced the oxygen-carrying capacity of these animals in hypoxic environments at that time or acted in the transport of hormones, detoxification of heavy metals, and immunity pathways.
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Affiliation(s)
- Elisa Maria Costa-Paiva
- Zoology Department, Institute of Biosciences, University of Sao Paulo, Sao Paulo, Brazil
- Geophysics and Atmospheric Sciences, Institute of Astronomy, University of Sao Paulo, Sao Paulo, Brazil
| | - Beatriz Mello
- Genetics Department, Biology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno Santos Bezerra
- Zoology Department, Institute of Biosciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Christopher J Coates
- Department of Biosciences, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - Kenneth M Halanych
- Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Federico Brown
- Zoology Department, Institute of Biosciences, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Ricardo I F Trindade
- Geophysics and Atmospheric Sciences, Institute of Astronomy, University of Sao Paulo, Sao Paulo, Brazil
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Abstract
Palaeoannelida Weigert and Bleidorn, 2016 is an old clade branching off at the base of the Annelida radiation. It includes two morphologically and ecological divergent groups of sedentary burrowers and tube-dwellers: Magelonidae Cunningham and Ramage, 1888, and Oweniidae Rioja, 1917. Magelonids are characterised by a flattened, shovel-shaped prostomium and a pair of ventral papillated palps. Oweniids have simplified bodies lacking parapodia or appendages and are easily distinguished by the presence of oval patches of packed uncini, each with two distal curved teeth. The present review aims to summarise available information about the diversity of forms and life strategies displayed in the group, providing some guidelines for species identification and the techniques commonly used for their study. In addition, the assumed geographic distributions of some taxa are critically discussed. A brief introduction about the evolutionary relationships, systematics, and taxonomic history is given for both Magelonidae and Oweniidae. The motivation of this review is to highlight the main knowledge gaps from a taxonomic, methodological, and geographic perspective, aiming at stimulating further research into members of this clade.
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A Cambrian crown annelid reconciles phylogenomics and the fossil record. Nature 2020; 583:249-252. [PMID: 32528177 DOI: 10.1038/s41586-020-2384-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/26/2020] [Indexed: 11/09/2022]
Abstract
The phylum of annelids is one of the most disparate animal phyla and encompasses ambush predators, suspension feeders and terrestrial earthworms1. The early evolution of annelids remains obscure or controversial2,3, partly owing to discordance between molecular phylogenies and fossils2,4. Annelid fossils from the Cambrian period have morphologies that indicate epibenthic lifestyles, whereas phylogenomics recovers sessile, infaunal and tubicolous taxa as an early diverging grade5. Magelonidae and Oweniidae (Palaeoannelida1) are the sister group of all other annelids but contrast with Cambrian taxa in both lifestyle and gross morphology2,6. Here we describe a new fossil polychaete (bristle worm) from the early Cambrian Canglangpu formation7 that we name Dannychaeta tucolus, which is preserved within delicate, dwelling tubes that were originally organic. The head has a well-defined spade-shaped prostomium with elongated ventrolateral palps. The body has a wide, stout thorax and elongated abdomen with biramous parapodia with parapodial lamellae. This character combination is shared with extant Magelonidae, and phylogenetic analyses recover Dannychaeta within Palaeoannelida. To our knowledge, Dannychaeta is the oldest polychaete that unambiguously belongs to crown annelids, providing a constraint on the tempo of annelid evolution and revealing unrecognized ecological and morphological diversity in ancient annelids.
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Parry L, Caron JB. Canadia spinosa and the early evolution of the annelid nervous system. SCIENCE ADVANCES 2019; 5:eaax5858. [PMID: 31535028 PMCID: PMC6739095 DOI: 10.1126/sciadv.aax5858] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/09/2019] [Indexed: 05/19/2023]
Abstract
Annelid worms are a disparate, primitively segmented clade of bilaterians that first appear during the early Cambrian Period. Reconstructing their early evolution is complicated by the extreme morphological diversity in early diverging lineages, rapid diversification, and sparse fossil record. Canadia spinosa, a Burgess Shale fossil polychaete, is redescribed as having palps with feeding grooves, a dorsal median antenna and biramous parapodia associated with the head and flanking a ventral mouth. Carbonaceously preserved features are identified as a terminal brain, circumoral connectives, a midventral ganglionated nerve cord and prominent parapodial nerves. Phylogenetic analysis recovers neuroanatomically simple extant taxa as the sister group of other annelids, but the phylogenetic position of Canadia suggests that the annelid ancestor was reasonably complex neuroanatomically and that reduction of the nervous system occurred several times independently in the subsequent 500 million years of annelid evolution.
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Affiliation(s)
- Luke Parry
- Department of Natural History, Palaeobiology, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario M5S 2C6, Canada
- Department of Geology and Geophysics, Yale University, New Haven, CT 06511, USA
- Corresponding author.
| | - Jean-Bernard Caron
- Department of Geology and Geophysics, Yale University, New Haven, CT 06511, USA
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada
- Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada
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9
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Nanglu K, Caron JB. A New Burgess Shale Polychaete and the Origin of the Annelid Head Revisited. Curr Biol 2019; 28:319-326.e1. [PMID: 29374441 DOI: 10.1016/j.cub.2017.12.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/11/2017] [Accepted: 12/08/2017] [Indexed: 11/28/2022]
Abstract
Annelida is one of the most speciose (∼17,000 species) and ecologically successful phyla. Key to this success is their flexible body plan with metameric trunk segments and bipartite heads consisting of a prostomium bearing sensory structures and a peristomium containing the mouth. The flexibility of this body plan has traditionally proven problematic for reconstructing the evolutionary relationships within the Annelida. Although recent phylogenies have focused on resolving the interrelationships of the crown group [1-3], many questions remain regarding the early evolution of the annelid body plan itself, including the origin of the head [4]. Here we describe an abundant and exceptionally well-preserved polychaete with traces of putative neural and vascular tissues for the first time in a fossilized annelid. Up to three centimeters in length, Kootenayscolex barbarensis gen. et sp. nov. is described based on more than 500 specimens from Marble Canyon [5] and several specimens from the original Burgess Shale site (both in British Columbia, Canada). K. barbarensis possesses biramous parapodia along the trunk, bearing similar elongate and thin notochaetae and neurochaetae. A pair of large palps and one median antenna project from the anteriormost dorsal margin of the prostomium. The mouth-bearing peristomium bears neuropodial chaetae, a condition that is also inferred in Canadia and Burgessochaeta from the Burgess Shale, suggesting a chaetigorous origin for the peristomial portion of the head and a secondary loss of peristomial parapodia and chaetae in modern polychaetes.
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Affiliation(s)
- Karma Nanglu
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 2J7, Canada.
| | - Jean-Bernard Caron
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 2J7, Canada; Department of Natural History Palaeobiology, Royal Ontario Museum, Toronto, ON M5S 2C6, Canada; Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada
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10
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Han J, Conway Morris S, Hoyal Cuthill JF, Shu D. Sclerite-bearing annelids from the lower Cambrian of South China. Sci Rep 2019; 9:4955. [PMID: 30894583 PMCID: PMC6426949 DOI: 10.1038/s41598-019-40841-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 02/19/2019] [Indexed: 11/16/2022] Open
Abstract
Cambrian annelids are strikingly diverse and reveal important details of annelid character acquisition. Their contribution, however, to a wider understanding of the evolution of the trochozoans (encompassing the annelids as well as such groups as the brachiopods and molluscs) remains limited. Thus the early annelids had been linked to a variety of cataphract Cambrian metazoans, notably Wiwaxia and the halkieriids, but recent work assigns such fossils to stem-group molluscs. Here we report two new annelids from the Lower Cambrian Chengjiang Lagerstätte, South China. Ipoliknus avitus n. gen., n. sp. is biramous with neurochaetae and notochaetae, but significantly also bears dorsal spinose sclerites and dorso-lateral dentate sclerites. Adelochaeta sinensis n. gen., n. sp. is unique amongst Cambrian polychaetes in possessing the rod-like supports of the parapodia known as aciculae. This supports phylogenetic placement of Adelochaeta as sister to some more derived aciculate Palaeozoic taxa, but in contrast Ipoliknus is recovered as the most basal of the stem-group annelids. Sclerites and chaetae of I. avitus are interpreted respectively as the remnants and derivatives of a once more extensive cataphract covering that was a characteristic of more primitive trochozoans. The two sets of chaetae (noto- and neurochaetae) and two sets of sclerites (spinose and dentate) suggest that in a pre-annelid an earlier and more complete scleritome may have consisted of four zones of sclerites. Other cataphract taxa from the Lower Palaeozoic show a variety of scleritome configurations but establishing direct links with such basal annelids as Ipoliknus at present must remain conjectural.
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Affiliation(s)
- Jian Han
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, 229 Taibai Road, Xi'an, 710069, P.R. China
| | - Simon Conway Morris
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK.
| | - Jennifer F Hoyal Cuthill
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK.,Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Degan Shu
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, 229 Taibai Road, Xi'an, 710069, P.R. China.
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11
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Ortega-Hernández J, Janssen R, Budd GE. The last common ancestor of Ecdysozoa had an adult terminal mouth. ARTHROPOD STRUCTURE & DEVELOPMENT 2019; 49:155-158. [PMID: 30458236 DOI: 10.1016/j.asd.2018.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
The Ecdysozoa is a major animal clade whose main uniting feature is a distinctive growth strategy that requires the periodical moulting of the external cuticle. The staggering diversity within Ecdysozoa has prompted substantial efforts to reconstruct their origin and early evolution. Based on palaentological and developmental data, we proposed a scenario for the early evolution of the ecdysozoan clade Panarthropoda (Onychophora, Tardigrada, Euarthropoda), and postulated that a terminal mouth is ancestral for this lineage. In light of the accompanying comment by Claus Nielsen, we take this opportunity to clarify the significance of our argumentation for Panarthropoda in the phylogenetic context of Ecdysozoa, and Bilateria more broadly. We conclude that the ancestral ecdysozoan most likely had an adult terminal mouth, and that the last common ancestors of all the phyla that constitute Ecdysozoa almost certainly also had an adult terminal mouth. The occurrence of a ventral-facing mouth in various adult ecdysozoans - particularly panarthropods - is the result of convergence. Despite the paucity of embryological data on fossil taxa, we contemplate the likelihood that a developmentally early ventral mouth opening could be ancestral for Ecdysozoa, and if so, then this would represent a symplesiomorphy of Bilateria as a whole.
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Affiliation(s)
- Javier Ortega-Hernández
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK; Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
| | - Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala se 752 36, Sweden
| | - Graham E Budd
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala se 752 36, Sweden
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12
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Bhambri A, Dhaunta N, Patel SS, Hardikar M, Bhatt A, Srikakulam N, Shridhar S, Vellarikkal S, Pandey R, Jayarajan R, Verma A, Kumar V, Gautam P, Khanna Y, Khan JA, Fromm B, Peterson KJ, Scaria V, Sivasubbu S, Pillai B. Large scale changes in the transcriptome of Eisenia fetida during regeneration. PLoS One 2018; 13:e0204234. [PMID: 30260966 PMCID: PMC6160089 DOI: 10.1371/journal.pone.0204234] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 09/05/2018] [Indexed: 12/16/2022] Open
Abstract
Earthworms show a wide spectrum of regenerative potential with certain species like Eisenia fetida capable of regenerating more than two-thirds of their body while other closely related species, such as Paranais litoralis seem to have lost this ability. Earthworms belong to the phylum Annelida, in which the genomes of the marine oligochaete Capitella telata and the freshwater leech Helobdella robusta have been sequenced and studied. Herein, we report the transcriptomic changes in Eisenia fetida (Indian isolate) during regeneration. Following injury, E. fetida regenerates the posterior segments in a time spanning several weeks. We analyzed gene expression changes both in the newly regenerating cells and in the adjacent tissue, at early (15days post amputation), intermediate (20days post amputation) and late (30 days post amputation) by RNAseq based de novo assembly and comparison of transcriptomes. We also generated a draft genome sequence of this terrestrial red worm using short reads and mate-pair reads. An in-depth analysis of the miRNome of the worm showed that many miRNA gene families have undergone extensive duplications. Sox4, a master regulator of TGF-beta mediated epithelial-mesenchymal transition was induced in the newly regenerated tissue. Genes for several proteins such as sialidases and neurotrophins were identified amongst the differentially expressed transcripts. The regeneration of the ventral nerve cord was also accompanied by the induction of nerve growth factor and neurofilament genes. We identified 315 novel differentially expressed transcripts in the transcriptome, that have no homolog in any other species. Surprisingly, 82% of these novel differentially expressed transcripts showed poor potential for coding proteins, suggesting that novel ncRNAs may play a critical role in regeneration of earthworm.
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Affiliation(s)
- Aksheev Bhambri
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
| | - Neeraj Dhaunta
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Surendra Singh Patel
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
| | - Mitali Hardikar
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Abhishek Bhatt
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Nagesh Srikakulam
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Shruti Shridhar
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Shamsudheen Vellarikkal
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
| | - Rajesh Pandey
- CSIR Ayurgenomics Unit - TRISUTRA, CSIR-IGIB, New Delhi, India
| | - Rijith Jayarajan
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Ankit Verma
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Vikram Kumar
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Pradeep Gautam
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | - Yukti Khanna
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
| | | | - Bastian Fromm
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Kevin J. Peterson
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Vinod Scaria
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
| | - Sridhar Sivasubbu
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
| | - Beena Pillai
- CSIR – Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), Mathura Road, Delhi, India
- * E-mail:
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13
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Dunn FS, Liu AG, Donoghue PCJ. Ediacaran developmental biology. Biol Rev Camb Philos Soc 2018; 93:914-932. [PMID: 29105292 PMCID: PMC5947158 DOI: 10.1111/brv.12379] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/18/2017] [Accepted: 09/22/2017] [Indexed: 01/23/2023]
Abstract
Rocks of the Ediacaran System (635-541 Ma) preserve fossil evidence of some of the earliest complex macroscopic organisms, many of which have been interpreted as animals. However, the unusual morphologies of some of these organisms have made it difficult to resolve their biological relationships to modern metazoan groups. Alternative competing phylogenetic interpretations have been proposed for Ediacaran taxa, including algae, fungi, lichens, rhizoid protists, and even an extinct higher-order group (Vendobionta). If a metazoan affinity can be demonstrated for these organisms, as advocated by many researchers, they could prove informative in debates concerning the evolution of the metazoan body axis, the making and breaking of axial symmetries, and the appearance of a metameric body plan. Attempts to decipher members of the enigmatic Ediacaran macrobiota have largely involved study of morphology: comparative analysis of their developmental phases has received little attention. Here we present what is known of ontogeny across the three iconic Ediacaran taxa Charnia masoni, Dickinsonia costata and Pteridinium simplex, together with new ontogenetic data and insights. We use these data and interpretations to re-evaluate the phylogenetic position of the broader Ediacaran morphogroups to which these taxa are considered to belong (rangeomorphs, dickinsoniomorphs and erniettomorphs). We conclude, based on the available evidence, that the affinities of the rangeomorphs and the dickinsoniomorphs lie within Metazoa.
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Affiliation(s)
- Frances S. Dunn
- School of Earth SciencesUniversity of BristolLife Sciences Building, 24 Tyndall Avenue, BristolBS8 1TQU.K.
- British Geological SurveyNicker Hill, Keyworth, NottinghamNG12 5GGU.K.
| | - Alexander G. Liu
- School of Earth SciencesUniversity of BristolLife Sciences Building, 24 Tyndall Avenue, BristolBS8 1TQU.K.
| | - Philip C. J. Donoghue
- School of Earth SciencesUniversity of BristolLife Sciences Building, 24 Tyndall Avenue, BristolBS8 1TQU.K.
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14
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Parapar J, Candás M, Cunha-Veira X, Moreira J. Exploring annelid anatomy using micro-computed tomography: A taxonomic approach. ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2017.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Earth's oldest 'Bobbit worm' - gigantism in a Devonian eunicidan polychaete. Sci Rep 2017; 7:43061. [PMID: 28220886 PMCID: PMC5318920 DOI: 10.1038/srep43061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/17/2017] [Indexed: 11/08/2022] Open
Abstract
Whilst the fossil record of polychaete worms extends to the early Cambrian, much data on this group derive from microfossils known as scolecodonts. These are sclerotized jaw elements, which generally range from 0.1-2 mm in size, and which, in contrast to the soft-body anatomy, have good preservation potential and a continuous fossil record. Here we describe a new eunicidan polychaete, Websteroprion armstrongi gen. et sp. nov., based primarily on monospecific bedding plane assemblages from the Lower-Middle Devonian Kwataboahegan Formation of Ontario, Canada. The specimens are preserved mainly as three-dimensional moulds in the calcareous host rock, with only parts of the original sclerotized jaw walls occasionally present. This new taxon has a unique morphology and is characterized by an unexpected combination of features seen in several different Palaeozoic polychaete families. Websteroprion armstrongi was a raptorial feeder and possessed the largest jaws recorded in polychaetes from the fossil record, with maxillae reaching over one centimetre in length. Total body length of the species is estimated to have reached over one metre, which is comparable to that of extant 'giant eunicid' species colloquially referred to as 'Bobbit worms'. This demonstrates that polychaete gigantism was already a phenomenon in the Palaeozoic, some 400 million years ago.
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Parry LA, Edgecombe GD, Eibye-Jacobsen D, Vinther J. The impact of fossil data on annelid phylogeny inferred from discrete morphological characters. Proc Biol Sci 2016; 283:20161378. [PMID: 27581880 PMCID: PMC5013799 DOI: 10.1098/rspb.2016.1378] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/08/2016] [Indexed: 12/30/2022] Open
Abstract
As a result of their plastic body plan, the relationships of the annelid worms and even the taxonomic makeup of the phylum have long been contentious. Morphological cladistic analyses have typically recovered a monophyletic Polychaeta, with the simple-bodied forms assigned to an early-diverging clade or grade. This is in stark contrast to molecular trees, in which polychaetes are paraphyletic and include clitellates, echiurans and sipunculans. Cambrian stem group annelid body fossils are complex-bodied polychaetes that possess well-developed parapodia and paired head appendages (palps), suggesting that the root of annelids is misplaced in morphological trees. We present a reinvestigation of the morphology of key fossil taxa and include them in a comprehensive phylogenetic analysis of annelids. Analyses using probabilistic methods and both equal- and implied-weights parsimony recover paraphyletic polychaetes and support the conclusion that echiurans and clitellates are derived polychaetes. Morphological trees including fossils depict two main clades of crown-group annelids that are similar, but not identical, to Errantia and Sedentaria, the fundamental groupings in transcriptomic analyses. Removing fossils yields trees that are often less resolved and/or root the tree in greater conflict with molecular topologies. While there are many topological similarities between the analyses herein and recent phylogenomic hypotheses, differences include the exclusion of Sipuncula from Annelida and the taxa forming the deepest crown-group divergences.
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Affiliation(s)
- Luke A Parry
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TH, UK
| | - Gregory D Edgecombe
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Danny Eibye-Jacobsen
- Zoological Museum, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Vinther
- University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TH, UK
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17
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Towards a systems-level understanding of development in the marine annelid Platynereis dumerilii. Curr Opin Genet Dev 2016; 39:175-181. [PMID: 27501412 DOI: 10.1016/j.gde.2016.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/30/2016] [Accepted: 07/07/2016] [Indexed: 01/12/2023]
Abstract
Platynereis dumerilii is a segmented marine worm from the phylum Annelida, a member of the Lophotrochozoans. Platynereis is easily maintained in the lab and exhibits a highly stereotypic development through spiral cleavage with a small, transparent, free-swimming larva highly suitable for microscopy studies. A protocol for embryo microinjection in Platynereis has enabled several genetic tools to be developed, paving the way for functional studies. Recent Platynereis studies have provided insights into the function of several signaling pathways in development. Platynereis has also proven a useful model system for comparative evolutionary developmental studies, allowing the formation of new hypotheses on the evolution of neuroendocrine signaling, body patterning, and organ development. Combining existing large datasets of spatial gene expression mapping, cell lineage mapping, and neuronal circuits with functional analyses of developmental genes represents a promising approach for future studies aiming at a systems-level understanding of development in Platynereis.
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19
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Parry LA, Wilson P, Sykes D, Edgecombe GD, Vinther J. A new fireworm (Amphinomidae) from the Cretaceous of Lebanon identified from three-dimensionally preserved myoanatomy. BMC Evol Biol 2015; 15:256. [PMID: 26577802 PMCID: PMC4650273 DOI: 10.1186/s12862-015-0541-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/11/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rollinschaeta myoplena gen. et sp. nov is described from the Late Cretaceous (Cenomanian) Konservat-Lagerstätten of Hakel and Hjoula, Lebanon. The myoanatomy of the fossils is preserved in exceptional detail in three dimensions as calcium phosphate, allowing the musculature of the body wall, gut and parapodia to be reconstructed in detail. RESULTS The major muscle groups of polychaetes can be identified in Rollinschaeta, including longitudinal muscle bands, circular muscles, oblique muscles, the parapodial muscle complex and the gut musculature, with a resolution sufficient to preserve individual fibres. To allow meaningful comparison with the phosphatized fossil specimens, extant polychaetes were stained with iodine and visualised using microCT. Rollinschaeta myoplena possesses two pairs of dorsal longitudinal muscles, dorsal and ventral circular muscles and a single pair of ventral longitudinal muscles. While six longitudinal muscle bands are known from other polychaete groups, their presence in combination with circular muscles is unique to Amphinomidae, allowing these fossils to be diagnosed to family level based solely on their myoanatomy. The elongate, rectilinear body and equally sized, laterally projecting parapodia of Rollinschaeta are found only within Amphinominae, demonstrating that the Cretaceous species is derived amongst Amphinomida. CONCLUSION The uniquely preserved myoanatomy of Rollinschaeta has allowed diagnosis of a fossil annelid to subfamily level using microCT as a comparative tool for exploring myoanatomy in fossil and extant polychaetes. Our results demonstrate that fossilized muscles can provide systematically informative anatomical detail and that they should be studied when preserved.
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Affiliation(s)
- Luke A Parry
- Bristol Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TH, UK. .,Department of Earth Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
| | - Paul Wilson
- Bristol Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TH, UK.
| | - Dan Sykes
- Imaging and Analysis Centre, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
| | - Gregory D Edgecombe
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
| | - Jakob Vinther
- Bristol Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TH, UK.
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