The Earliest Known Pelagic Jellyfish Found in Stage 3 Cambrian China

The earliest pelagic jellyfish with rhopalia from Cambrian chengjiang Lagerstätte

Authors:

Han et al

Abstract:

Modern cnidarian medusae generally show a triphasic life cycle with a succession of a larva, a sessile polyp and a pelagic medusa stage. The debate around the metagenesis of sessile polyps into pelagic medusae has lasted for more than 100 years. When pelagic forms originated is not clear. Hitherto the earliest crown-group medusae have been found at Cambrian Stage 5 (traditional Middle Cambrian, 509 Ma) in Utah, while diverse stem-group medusozoans were found in the basal Cambrian Fortunian Stage. No reliable medusae have been found from Cambrian Series 2 Stage 3 (ca. 521 Ma), although the marine benthic community teemed with many phyla of bilaterians, sponges, and ctenophores. Here we reinterpret Yunnanoascus haikouensis Hu et al., 2007, originally described as a ctenophore, as a pelagic, predatory, crown-group medusozoan, based on the presence of rhopalia, possible radial canals, and marginal tentacles. The medusae were a predatory member of the pelagic food web at the middle level of the ocean at Cambrian Stage 3.

Corumbella: A Controversial, but Common Skeletonized Ediacaran NeoProterozoic Scyphozoan Cnidarian

Insights into the Skeletonization, Lifestyle, and Affinity of the Unusual Ediacaran Fossil Corumbella

Authors:

Forancelli Pacheco et al

Abstract:

The Ediacaran fossil Corumbella is important because it is hypothesized to be a scyphozoan cnidarian, and thus might be one of the rare examples of bona fide Neoproterozoic animals. Unfortunately, its mode of life, style of skeletonization, and taxonomic affinity have been very controversial. Here, we use X-ray micro-CT, SEM, and taphonomic analysis to compare preservational modes of Corumbella, in order to better understand the symmetry, mode of construction, preservational style, and taxonomy of this group. Results suggest that articulated and disarticulated specimens of Corumbella from the Ediacaran of Brazil, Paraguay, and the United States, although sometimes preserved very differently, represent the same taxon—Corumbella werneri. Corumbellids had a thick but flexible theca and probably lived with their basalmost part anchored in the sediment, much like Conotubus. When considered together, these results suggest that Corumbella was one of the first animals to build a skeleton, employing a lamellar microfabric similar to conulariids.

Dendrogramma: Wait! What?! Did They say It Looks Like a Ediacaran Lifeform?

Scientists discovered two new species of sea-dwelling, mushroom-shaped organisms, according to a study published September 3, 2014 in the open-access journal PLOS ONE by Jean Just from University of Copenhagen, Denmark, and colleagues.

Scientists classify organisms based on shared characteristics using a taxonomic rank, including kingdom, phylum, and species. In 1986, the authors of this study collected organisms at 400 and 1000 meters deep on the south-east Australian continental slope and only just recently isolated two types of mushroom-shaped organisms that they couldn't classify into an existing phylum.

The new organisms are multicellular and mostly non-symmetrical, with a dense layer of gelatinous material between the outer skin cell and inner stomach cell layers. The organisms were classified as two new species in a new genus, Dendrogramma enigmatica and Dendrogramma discoides, in the new family, Dendrogrammatidae. Scientists found similarities between the organisms and members of Ctenophora and Cnidaria and suggest that they may be related to one of these phyla. Scientists also found similarities to 600 million year-old Pre-Cambrian extinct life forms, suggested by some to be early but failed attempts at multi-cellular life.

The authors originally preserved the specimens in neutral formaldehyde and stored them in 80% ethanol, which makes them unsuitable for molecular analysis. However, they suggest attempting to secure new samples for further study, which may provide further insight into their relationship to other organisms.

link.

Haootia quadriformis: a Muscular Cnidarian From Ediacaran NeoProterozoic Newfoundland, Canada

Lucernaria quadricornis (extant) and Haootia quadriformis (ediacaran)

Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma)

Authors:

Liu et al

Abstract:

Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.

Narrowing in on Cnidaria's NeoProterozoic Origin

Origin and early diversification of the phylum Cnidaria Verrill: major developments in the analysis of the taxon's Proterozoic–Cambrian history

Authors:

Van Iten et al

Abstract:

Diploblastic eumetazoans of the phylum Cnidaria originated during the Neoproterozoic Era, possibly during the Cryogenian Period. The oldest known fossil cnidarians occur in strata of Ediacaran age and consist of polypoid forms that were either nonbiomineralizing or weakly so. The oldest possible anthozoans, including the genus Ramitubus, may be related to tabulate corals and occur in the Doushantuo Lagerstätte (upper Doushantuo Formation, South China), the age of which is poorly constrained (approximately 585 Ma?). Conulariid scyphozoans may first appear as early as 635–577 Ma (Lantian Formation, South China). A definite conulariid, most similar to Palaeozoic species assigned to the genus Paraconularia, occurs in association with the possible scyphozoan, Corumbella werneri, in the latest Ediacaran (c. 543 Ma) Tamengo Formation of Brazil. Basal Cambrian (c. 540 Ma) phosphorites in the upper Kuanchuanpu Formation (South China) yield solitary polyps of the oldest probable anthozoan (Eolympia pediculata), which appears to have been a stem hexacorallian. This same formation contains fossils interpreted by some authors as pentaradial cubozoan polyps; however, both the oldest known cubozoans and the oldest hydrozoans, all medusae, may actually occur in the Cambrian (Series 3, c. 505 Ma) Marjum Formation (Utah, USA). Although these recently published palaeontological data tend to corroborate the hypothesis that Cnidaria has a relatively deep Neoproterozoic history, the timing of major internal branching events remains poorly constrained, with, for example, the results of some molecular clock analyses indicating that the two cnidarian subphyla (Anthozoaria and Medusozoa) may have originated as many as one billion years ago. Further progress towards elucidating the evolution and early fossil record of cnidarians may accrue from: (1) an intensive search for phosphatized soft parts in possible anthozoans from the Ediacaran Doushantuo Formation; (2) an expanded search for Ediacaran conulariids; and (3) additional detailed analyses of the taphonomy and preservation of Ediacaran and Cambrian cnidarians, including possible pentaradial cubozoan polyps from the Fortunian upper Kuanchuanpu Formation.

A Cryptic Coral-crinoid "Hanging Garden" From Eifelian/Givetian Devonian Morocco

Cryptic coral-crinoid "hanging gardens" from the Middle Devonian of southern Morocco

Authors:

Jakubowicz et al

Abstract:

An unusual and exceptionally well preserved cryptic community of cnidarians, crinoids, sponges, and microbes developed in a submarine cavity of Middle Devonian age in the Hamar Laghdad area (Morocco). The biota encrusted the cavity roof and grew predominantly in an upside-down position, forming spectacular "hanging gardens." The investigated assemblage differs strikingly from both its Paleozoic and modern analogues; it constitutes one of a very few known examples of fossil cryptic assemblages developed in relatively deep water settings, and is the first report of a cryptic paleoecosystem dominated by rugose corals. The results support the view that during the middle Paleozoic there was no distinct polarization between open-surface and cryptic faunas in deep-water environments, but keen competition for space already existed in Devonian cryptic assemblages. The regional species pool seems to have been the main determinant of the ecological succession and structure of this cryptic community.

Edicaran Aspidella Acts Like a Cnidarian

Evidence for Cnidaria-like behavior in ca. 560 Ma Ediacaran Aspidella

Authors:

1. Latha R. Menon (a)
2. Duncan McIlroy (b)
3. Martin D. Brasier (a,b)

Affiliations:

a. Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK

b. Department of Earth Sciences, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X5, Canada

Abstract:

The first appearance of animals in the geological record is a matter of continuing debate: how deep were the roots of the Cambrian explosion? Molecular clock estimates indicate that the deepest divergences of the Metazoa had occurred by the Ediacaran Period (635–541 Ma), yet evidence of animal activity from well below the Ediacaran-Cambrian boundary has been rare and often questionable. Meanwhile, the Ediacaran macrobiota has remained enigmatic, as emphasized by recent controversial claims that South Australia Ediacaran forms were not marine animals at all, but land-based lichens and microbial colonies. Here we report evidence for animal-like behavior in a submerged setting in a key Ediacaran form, Aspidella terranovica Billings 1872, a discoidal fossil from the ca. 560 Ma Fermeuse Formation of Newfoundland (Canada). We describe sedimentary fabrics indicating progressive vertical movement of an organism through sediment in response to an aggrading sediment-water interface. Such equilibrium traces are familiar from the Phanerozoic and are observed in partially buried marine animals such as tube anemones today. Furthermore, horizontal trails closely comparable to trails previously described from ∼565 m.y. old Mistaken Point (Newfoundland) are now linked to Aspidella. Our findings constitute evidence of both vertical and horizontal movement in a key Ediacaran taxon, consistent with an animal of cnidarian grade. Moreover, because Aspidella is also reported from the Rawnsley Quartzite of South Australia, our evidence conflicts with the proposed radical interpretation of that Ediacaran fossil assemblage. We demonstrate that at least some Ediacaran forms were probably early animals, and that they lived underwater.

Your Algae is Really a Jellyfish: Ediacaran Algae Fossils Reinterpreted as Cnidarians

Alternative interpretations of some earliest Ediacaran fossils from China

Authors:

1. Heyo Van Iten (a)
2. Juliana De M. Leme (b)
3. Antonio C. Marques (c)
4. Marcello G. Simões (d)

Affiliations:

a. Department of Geology, Hanover College, Hanover, IN 47243, USA

b. Department of Sedimentary and Environmental Geology, University of São Paulo, 05580-080, São Paulo, SP, Brazil

c. Department of Zoology, University of São Paulo, Rua do Matão, Travessa 14, 101, 05508-090, São Paulo, SP, Brazil

d. Department of Zoology, São Paulo State University, 18.618-000, Botucatu, SP, Brazil

Abstract:

In a letter to Nature (February, 2011), Xunlai Yuan and collaborators recorded carbon compression fossils from black shales of the Lantian Formation (Ediacaran), southern Anhui Province, South China. The new fossils, described under five morphological types (Types A to E), exhibit degrees of morphological differentiation suggesting that they were multicellular eukaryotes. Some of the Lantian macrofossils were interpreted as algae, but others are of unknown affinities. For reasons noted in this discussion, Type A fossils attracted our particular attention, and we suggest an alternative interpretation of their affinities. According to our view, some of them (at least those with three faces and no globose holdfast at their base) may represent conulariid cni−darians or close medusozoan relatives. The undistorted organism probably was a three−sided cone in life. We believe that our suggested alternative interpretations of the anatomy and affinities of the fossils in question can be useful in guiding future research on the oldest currently known fossil assemblage of multicellular organisms.

Exquisite Cnidarian Fossils From the Early Cambrian

Embryos, polyps and medusae of the Early Cambrian scyphozoan Olivooides

Authors:

1. Xi-Ping Dong (a,b)
2. John A. Cunningham (c)
3. Stefan Bengtson (d)
4. Ceri-Wyn Thomas (c)
5. Jianbo Liu (a)
6. Marco Stampanoni (e,f)
7. Philip C. J. Donoghue (c)

Affiliations:

a. School of Earth and Space Science, Peking University, Beijing 100871, People's Republic of China

b. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China

c. School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK

d. Department of Palaeozoology and Nordic Center for Earth Evolution, Swedish Museum of Natural History, PO Box 50007, Stockholm 104 05, Sweden

e. Swiss Light Source, Paul Scherrer Institut, Villigen 5232, Switzerland

f. Institute for Biomedical Engineering, University of Zürich and ETH Zürich, Rämistrasse, Zürich 8006, Switzerland

Abstract:

The Early Cambrian organism Olivooides is known from both embryonic and post-embryonic stages and, consequently, it has the potential to yield vital insights into developmental evolution at the time that animal body plans were established. However, this potential can only be realized if the phylogenetic relationships of Olivooides can be constrained. The affinities of Olivooides have proved controversial because of the lack of knowledge of the internal anatomy and the limited range of developmental stages known. Here, we describe rare embryonic specimens in which internal anatomical features are preserved. We also present a fuller sequence of fossilized developmental stages of Olivooides, including associated specimens that we interpret as budding ephyrae (juvenile medusae), all of which display a clear pentaradial symmetry. Within the framework of a cnidarian interpretation, the new data serve to pinpoint the phylogenetic position of Olivooides to the scyphozoan stem group. Hypotheses about scalidophoran or echinoderm affinities of Olivooides can be rejected.

Jellyfish Blooms Don't Necessarily Mean What You Think

Recurrent jellyfish blooms are a consequence of global oscillations

Authors:

1. Robert H. Condon (a,*)

2. Carlos M. Duarte (b,c)

3. Kylie A. Pitt (d)

4. Kelly L. Robinson (a,e)

5. Cathy H. Lucas (f)

6. Kelly R. Sutherland (g)

7. Hermes W. Mianzan (h)

8. Molly Bogeberg (a)

9. Jennifer E. Purcell (i)

10. Mary Beth Decker (j)

11. Shin-ichi Uye (k)

12. Laurence P. Madin (l)

13. Richard D. Brodeur (m)

14. Steven H. D. Haddock (n)

15. Alenka Malej (o)

16. Gregory D. Parry (p)

17. Elena Eriksen (q)

18. Javier Quiñones (r)

19. Marcelo Acha (h)

20. Michel Harvey (s)

21. James M. Arthur (d)

22. William M. Graham (t)

Author Affiliations:

a. Dauphin Island Sea Laboratory, Marine Environmental Sciences Consortium, Dauphin Island, AL 36528;

b. University of Western Australia Oceans Institute, University of Western Australia, Crawley, WA 6009, Australia;

c. Department of Global Change Research, Instituto Mediterráneo de Estudios Avanzados, Universidad de las Islas Baleares y el Consejo Superior de Investigaciones Científicas, 01790 Esporles, Spain;

d. Australian Rivers Institute and Griffith School of Environment, Griffith University, Gold Coast Campus, QLD 4111, Australia;

e. Department of Marine Sciences, University of South Alabama, Mobile, AL 36688;

f. National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, United Kingdom;

g. Department of Biology, University of Oregon, Eugene, OR 97403;

h. Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Instituto Nacional de Investigación y Desarrollo Pesquero, Mar del Plata B7602HSA, Argentina;

i. Shannon Point Marine Center, Western Washington University, Anacortes, WA 98221;

j. Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520;

k. Department of Environmental Dynamics and Management, Hiroshima University, Higashi-Hiroshima 739-8528, Japan;

l. Woods Hole Oceanographic Institution, Woods Hole, MA 02543;

m. Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration Fisheries, Newport, OR 97365;

n. Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039;

o. Marine Biology Station Piran, National Institute of Biology, 6330 Piran, Slovenia;

p. Department of Primary Industries, Victorian Fisheries, Queenscliff 3225, VIC, Australia;

q. Institute of Marine Research, 5817 Bergen, Norway;

r. Laboratorio Costero de Pisco, Instituto del Mar del Perú, Paracas, 11550 Ica, Peru;

s. Direction des sciences océaniques et de l'environnement, Institut Maurice-Lamontagne, Pêches et Océans Canada, Mont-Joli, QC, Canada G5H 3Z4;

t. Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529

Abstract:

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

Now THAT'S an author list!