Hypothesized Cambrian medusae from Saint John, New Brunswick, reinterpreted as sedimentary structures

Hagadorn, James W.; Miller, Randall F.

doi:10.4138/atlgeol.2011.002

Cited by 17 publications

(14 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other Phanerozoic discoidal structures are known to have been produced abiogenically [99,100]. Scratch circles in particular are known throughout the Phanerozoic, including specimens from the Cambrian of Ireland [18,70] originally assigned to Nimbia by Crimes et al [101], and examples from the Paleocene of Italy produced by foraminifera [102].…”

Section: Discussionmentioning

confidence: 99%

Cryptic Disc Structures Resembling Ediacaran Discoidal Fossils from the Lower Silurian Hellefjord Schist, Arctic Norway

Kirkland

MacGabhann

Kirkland³

et al. 2016

PLoS ONE

View full text Add to dashboard Cite

The Hellefjord Schist, a volcaniclastic psammite-pelite formation in the Caledonides of Arctic Norway contains discoidal impressions and apparent tube casts that share morphological and taphonomic similarities to Neoproterozoic stem-holdfast forms. U-Pb zircon geochronology on the host metasediment indicates it was deposited between 437 ± 2 and 439 ± 3 Ma, but also indicates that an inferred basal conglomerate to this formation must be part of an older stratigraphic element, as it is cross-cut by a 546 ± 4 Ma pegmatite. These results confirm that the Hellefjord Schist is separated from underlying older Proterozoic rocks by a thrust. It has previously been argued that the Cambrian Substrate Revolution destroyed the ecological niches that the Neoproterozoic frond-holdfasts organisms occupied. However, the discovery of these fossils in Silurian rocks demonstrates that the environment and substrate must have been similar enough to Neoproterozoic settings that frond-holdfast bodyplans were still ecologically viable some hundred million years later.

show abstract

Section: Discussionmentioning

confidence: 99%

Cryptic Disc Structures Resembling Ediacaran Discoidal Fossils from the Lower Silurian Hellefjord Schist, Arctic Norway

Kirkland

MacGabhann

Kirkland³

et al. 2016

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…ReMARKS: The rock record is rife with discoidal and stellate structures, many of which have been described as trace or body fossils (e.g., Young and Hagadorn 2010;Hagadorn and Miller 2011). Although some such structures are biogenic, inorganic processes form most of them, and interpretations are rarely based on more than an analogy with modern organisms and processes (e.g., Reineck and Singh 1980;Ricci Lucchi 1995).…”

Section: Incertae Sedismentioning

confidence: 99%

Insights into an Early Jurassic dinosaur habitat: ichnofacies and enigmatic structures from the Portland Formation, Hoover Quarry, Massachusetts, U.S.A.

Collette

Getty²,

Hagadorn

2011

atgeol

Self Cite

View full text Add to dashboard Cite

Jurassic sandstones of the Hartford Basin are well known for their dinosaur trackways, but few studies have characterized their invertebrate ichnofaunas. A notable Portland Formation exposure in this area is the Hoover Quarry in East Longmeadow, Massachusetts, where vertebrate skeletal material (the type specimen of the crocodilian Stegomosuchus longipes) occurs in association with a diverse ichnofauna. Hoover Quarry ichnogenera include Eubrontes cf. gracilis, Planolites beverleyensis, Planolites montanus, probable Scoyenia burrows, and Skolithos isp. Also preserved at the site is Palaeophycus tortuosus, a sinusoidal burrow that had been previously synonymized with Palaeophycus tubularis. A probable Skolithos burrow termination with an unusual pattern of scratches also occurs, along with several problematic stellate structures. At this site, primary sedimentary structures on trace bearing surfaces are consistent with deposition in a shallow aquatic environment that was periodically emergent. Viewed in the context of nearby sections of the Portland Formation, Hoover Quarry exposures could have been deposited in fluvial, ephemeral lacustrine, or playa environments. Traces in the Hoover Quarry indicate Scoyenia-Skolithos-composite ichnofacies, elements of which are commonly produced in continental firmground environments. RÉSUMÉLes grès du Jurassique dans le bassin de Hartford sont reconnus pour la présence d'empreintes de dinosaures. Mais peu d'études ont permis de caractériser l'ichnofaune invertébrée qu'on peut également y observer. Un affleurement notable de la Formation Portland dans la région est présent dans la carrière Hoover, à East Longmeadow, au Massachusetts, où des matériaux de squelettes de vertébrés (le spécimen type du crocodilien Stegomosuchus longipes) et une ichnofaune diversifiée sont présents. L'ichnofaune de la carrière Hoover comprend les espèces comme Eubrontes cf. gracilis, Planolites beverleyensis, Planolites montanus, vraisemblablement des terriers de Scoyenia, et Skolithos. Il y a également sur le site l'espèce Palaeophycus tortuosus, un terrier sinusoïdal qui a déjà été nommé Palaeophycus tubularis. L'extrémité d'un terrier de l'espèce probable Skolithos accompagnée d'une série inusitée de stries ou d'éraflures est en outre présente, tout comme plusieurs structures étoilées dont l'origine demeure mystérieuse. Sur le site, des structures primaires sur des surfaces marquées de traces correspondraient à une sédimentation dans un milieu aquatique peu profond qui a émergé à intervalles périodiques. Considéré dans le contexte des sections de la Formation Portland, situées à proximité, le dépôt des affleurements de la carrière Hoover pourrait être survenu dans un milieu fluvial, lacustre éphémère ou en présence d'un lac temporaire. Les traces relevées dans la carrière Hoover indiquent la présence d'un ichnofaciès composite de type Scoyenia-Skolithos, dont les éléments sont couramment produits dans un milieu de sol continental à cohésion moyenne.[Traduit par la redaction]

show abstract

“…Finally, because of their elliptical and acuminated shapes, their peripheral rims, their indistinct central depressions and their sizes, these Brioverian elliptical fossils somehow correspond to Cambrian organisms from New Brunswick published by Hagadorn & Miller (, fig. g, h).…”

Section: Discussionmentioning

confidence: 71%

First evidence of Ediacaran–Fortunian elliptical body fossils in the Brioverian series of Brittany, NW France

Néraudeau

Dabard

Albani

et al. 2018

LET

View full text Add to dashboard Cite

Body fossils are described for the first time from the Upper Brioverian (Ediacaran–Fortunian) deposits of Central Brittany (NW France). The material consists of a dozen of specimens preserved on two slates, recently collected in a quarry in Saint‐Gonlay. The fossils, centimetric in size, have an elliptical and acuminated outline, with a peripheral bulge but without conspicuous concentric or radial lines. These body fossils are preserved in slates that are locally rich in grazing traces, sometimes associated with microbial mats. The sedimentological characteristics of these deposits correspond to a shallow marine shelf environment, with a low to moderate hydrodynamism. Such findings, in concomitance with previous ichnological discoveries, unravel the potential of the Brioverian strata from Brittany as a new locality to provide answers on Ediacaran and early Cambrian biocenoses.

show abstract

Hypothesized Cambrian medusae from Saint John, New Brunswick, reinterpreted as sedimentary structures

Cited by 17 publications

References 34 publications

Cryptic Disc Structures Resembling Ediacaran Discoidal Fossils from the Lower Silurian Hellefjord Schist, Arctic Norway

Cryptic Disc Structures Resembling Ediacaran Discoidal Fossils from the Lower Silurian Hellefjord Schist, Arctic Norway

Insights into an Early Jurassic dinosaur habitat: ichnofacies and enigmatic structures from the Portland Formation, Hoover Quarry, Massachusetts, U.S.A.

First evidence of Ediacaran–Fortunian elliptical body fossils in the Brioverian series of Brittany, NW France

Contact Info

Product

Resources

About