scholarly journals Symbiosis in the Cambrian: enteropneust tubes from the Burgess Shale co-inhabited by commensal polychaetes

2021 ◽  
Vol 288 (1951) ◽  
pp. 20210061
Author(s):  
Karma Nanglu ◽  
Jean-Bernard Caron
Keyword(s):  
Fossil Record ◽  
First Record ◽  
Animal Behaviour ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Reproductive Structures ◽  
Ecological Relationship

The in situ preservation of animal behaviour in the fossil record is exceedingly rare, but can lead to unique macroecological and macroevolutionary insights, especially regarding early representatives of major animal clades. We describe a new complex ecological relationship from the middle Cambrian Burgess Shale (Raymond Quarry, Canada). More than 30 organic tubes were recorded with multiple enteropneust and polychaete worms preserved within them. Based on the tubicolous nature of fossil enteropneusts, we suggest that they were the tube builders while the co-preserved polychaetes were commensals. These findings mark, to our knowledge, the first record of commensalism within Annelida and Hemichordata in the entire fossil record. The finding of multiple enteropneusts sharing common tubes suggests that either the tubes represent reproductive structures built by larger adults, and the enteropneusts commonly preserved within are juveniles, or these enteropneusts were living as a pseudo-colony without obligate attachment to each other, and the tube was built collaboratively. While neither hypothesis can be ruled out, gregarious behaviour was clearly an early trait of both hemichordates and annelids. Further, commensal symbioses in the Cambrian may be more common than currently recognized.

scholarly journals Synchrotron imagery of phosphatized eggs in Waptia cf. W. fieldensis from the middle Cambrian (Miaolingian, Wuliuan) Spence Shale of Utah

2021 ◽  
pp. 1-12
Author(s):  
Justin Moon ◽  
Jean-Bernard Caron ◽  
Robert R. Gaines
Keyword(s):  
First Record ◽  
Early Ontogeny ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
X Ray ◽  
Mineral Phases ◽  
Attachment Structures ◽  
Egg Membrane ◽  
Evo Devo

Abstract Exceptionally preserved fossil eggs and embryos provide critical information regarding paleoembryogenesis, reproductive strategies, and the early ontogeny of early arthropods, but the rarity of preservation of both eggs and egg-bearing organisms in situ limits their use in detailed evolutionary developmental (evo-devo) studies. Burgess Shale-type deposits preserve rare instances of egg-bearing arthropods as carbonaceous compressions; however, the eggs are usually poorly preserved with no compelling evidence of embryos. We describe the first record of a brooding specimen of Waptia cf. W. fieldensis from the Spence Shale, a Cambrian (Wuliuan Stage) Burgess Shale-type deposit in northeastern Utah and southeastern Idaho. This is the first record of an egg-bearing arthropod from the Spence Shale and it exhibits two distinct modes of preservation among eggs within the single clutch: carbonization and phosphatization. Unlike the egg-bearing Burgess Shale specimens, many eggs of this Utah specimen are also preserved three-dimensionally. In addition, synchrotron radiation X-ray tomographic microscopy reveals internal distributions of mineral phases, along with potential remnants of the egg membrane and attachment structures, but, as in the Burgess Shale, no explicit traces of developing embryos. The distinct modes of preservation highlight the existence of diagenetic microenvironments within some eggs, but not in others during fossilization.

scholarly journals Presence of Naraoia Walcott, 1912 (Nektaspida, Arthropoda) in the middle Cambrian of Europe (Murero, NE Spain)

2018 ◽  
Vol 33 (1) ◽  
pp. 83
Author(s):  
Rodolfo Gozalo ◽  
Mª Eugenia Dies-Álvarez ◽  
José Antonio Gámez VIintaned ◽  
Juan B. Chirivella ◽  
Eladio Liñan
Keyword(s):  
British Columbia ◽  
First Record ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Evolutionary Potential ◽  
Middle Cambrian ◽  
The Family ◽  
Ne Spain

 The genus Naraoia Walcott, 1912, a Burgess Shale-type fossil known from the lower and middle Cambrian of British Columbia (Canada), Idaho and Utah (USA), as well as from Yunnan and Guizhou provinces (China), is now reported from the middle Cambrian of Murero (Zaragoza, Spain), which is the first record in the Acadobaltic province. The only fragmented specimen found is determined as Naraoia sp., its age being Pardailhania multispinosa Zone (Drumian Stage). This new datum reinforces the hypothesis of the existence of a cosmopolitan faunal substrate in early Cambrian times, which is to some extent refl ected in the mid Cambrian by faunal groups of low evolutionary potential as the family Naraoiidae and other soft-bodied fossil taxa.

scholarly journals First record of the brachiopodLingulella waptaensiswith pedicle from the Middle Cambrian Burgess Shale

2010 ◽  
Vol 91 (2) ◽  
pp. 150-162 ◽  
Author(s):  
Sandra Pettersson Stolk ◽  
Lars Erik Holmer ◽  
Jean-Bernard Caron
Keyword(s):  
First Record ◽  
Burgess Shale ◽  
Middle Cambrian

A redescription of a rare chordate, Metaspriggina Walcotti Simonetta and Insom, from the Burgess Shale (Middle Cambrian), British Columbia, Canada

2008 ◽  
Vol 82 (2) ◽  
pp. 424-430 ◽  
Author(s):  
Simon Conway Morris
Keyword(s):  
Fossil Record ◽  
Early History ◽  
Fish Scales ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
New Information ◽  
History Of ◽  
The One ◽  
Modes Of Life ◽  
Chengjiang Lagerstätte

Until Recently, our understanding of the earliest history of the fish has been fragmentary in terms of the fossil record and conjectural with respect to many details of phylogeny. Fortunately, significant new information has become available in recent years, most notably from the discoveries of at least three taxa of agnathan fish from the Lower Cambrian Chengjiang Lagerstätte of Yunnan, China (Shu et al., 1999, 2003; Shu, 2003; see also Hou et al., 2002; Hou et al., 2004, p. 192-193; Zhang and Hou, 2004). Two of the taxa (Haikouichthys and Zhangjianichthys) are represented by numerous specimens, but it is noteworthy that amongst the forty-odd Burgess Shale-type occurrences apart from the Chengjiang Lagerstätte, chordates (or indeed cephalochordates and urochordates) are otherwise unknown. The one exception is the Burgess Shale itself, characterized by the rather enigmatic Pikaia gracilens (Conway Morris, 1982, 1998) and the much rarer chordate described herein. Apart from this exceptionally preserved material, the fossil record effectively only begins in the Ordovician (e.g., Sansom et al., 2001, 2005; Sansom and Smith, 2005), in as much putative fish scales from the latest Cambrian (Young et al., 1996) may be better interpreted as arthropodan (see Smith et al., 2001, p. 78). The difficulties of interpreting what is overall an extremely patchy record are further compounded by the fact that the relevance to this early history of the extant agnathan hagfish and lamprey has remained (and indeed to some extent remains) problematic, given the uncertainty as to which of the presumed archaic features have been overprinted by specializations for modes of life that might have had little counterpart in the ancestral forms.

The persistence of Burgess Shale-type faunas: implications for the evolution of deeper-water faunas

1989 ◽  
Vol 80 (3-4) ◽  
pp. 271-283 ◽  
Author(s):  
S. Conway Morris
Keyword(s):  
Lower Cambrian ◽  
Burgess Shale ◽  
Middle Cambrian

ABSTRACTDiscoveries, most of them recently, in more than thirty Lower and Middle Cambrian horizons with soft-bodied fossils have shown that forty-one of the genera occur also in the celebrated Burgess Shale (Middle Cambrian). Significantly, they tend to have lengthy stratigraphic durations which together encompass an interval from the early Lower Cambrian (Tommotian) to near the end of the Middle Cambrian. At least some genera have also wide geographical ranges, with occurrences around much of the Laurentian (N America) craton, and also in N and S China, Australia, Siberia, Spain and Poland. Although a few genera, e.g. Isoxys, may have been pelagic, for the most part these distributions are explained in terms of a deeper-water biota with an evolutionarily conservative aspect. Both the origins and further recruitment to this biota may have been from shallower water, with more limited in situ diversification. It is speculated that this distinctive Cambrian biota was gradually driven to extinction with the arrival of Ordovician competitors, although some relics may have survived until at least the Devonian. This history has implications for our understanding of deeper-water faunas throughout the Phanerozoic, and supports the notion that archaic forms may take refuge in this environment.

scholarly journals First record of Ubaghsicystis (Eocrinoidea - Echinodermata) from the Cambrian (Miaolingian, Wuliuan) of Sonora, Mexico: Biostratigraphical and paleoecological considerations

2021 ◽  
Vol 69 (Suppl.1) ◽  
pp. 51-65
Author(s):  
Blanca-Estela Buitrón-Sánchez ◽  
Francisco-Javier  Cuen-Romero ◽  
Matilde-Sylvia Beresi ◽  
Rogelio Monreal
Keyword(s):  
Marine Environment ◽  
Research Work ◽  
First Record ◽  
Sedimentary Sequence ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Stratigraphic Section ◽  
Invertebrate Fossils ◽  
First Time ◽  
Open Shelf

Introduction: The present work constitutes the first record of Ubaghsicystis Gil-Cid & Domínguez-Alonso (Echinodermata-Eocrinoidea) in the El Gavilán Formation, exposed in the El Sahuaral Hill, a new Cambrian locality of central Sonora, Mexico. The El Gavilán Formation is a sedimentary sequence mainly made up of shale interbedded with limestone, with abundant invertebrate fossils, deposited in an open shelf marine environment. Objective: The main objective of this research work is to describe the species Ubaghsicystis cf. U. segurae for the first time in Mexico, in addition to biostratigraphic and paleoecological considerations. Methods: A composite stratigraphic section of the El Gavilán Fm. was measured in central Sonora, where samples corresponding to eocrinods were collected, the material was examined in the Microscope Leica MZ10.  Results: The biotic association is composed of reticulosan sponges, chancelloriids (Chancelloria eros, Allonnia tintinopsis, Archiasterella sp.), hyolithids, brachiopods, trilobites (Quadragnostus depressa, Peronopsis sp., Tonkinella valida, and Elrathina sp.), and echinoderms (Ubaghsicystis cf. U. segurae). Regarding the age, the trilobite association establishes a chronostratigraphic position from the middle Cambrian (Miaolingian, Wuliuan), Altiocculus Subzone, Ehmaniella Zone. The material studied is constituted by isolated echinoderm plates, which probably represent various cycles of theca plates assigned to Ubaghsicystis cf. U. segurae. The genus Ubaghsicystis has been scarcely recorded in a few Cambrian regions (e.g., Burgess Shale in Canada and Los Barrios de Luna in Spain), so that the information about this taxon is limited. Conclusions: The Cambrian succession of Sonora, where Ubaghsicystis occurred, was part of the border from the Laurentia craton during this period, located near the Paleoequator during this period, where ideal conditions for increasing diversity and abundance of species were developed, including echinoderms.

New phylogenetic insights into the Cambrian radiation of arachnomorph arthropods

2008 ◽  
Vol 82 (3) ◽  
pp. 585-594 ◽  
Author(s):  
Jonathan R. Hendricks ◽  
Bruce S. Lieberman
Keyword(s):  
Fossil Record ◽  
Cladistic Analysis ◽  
New Genera ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Cambrian Radiation ◽  
Character Matrix

The Cambrian fossil record of the Arachnomorpha is rich and diverse and includes trilobites, chelicerates, and many taxa known from various soft-bodied faunas including the Burgess Shale and the Chengjiang. Exceptionally well-preserved arthropod fossils are also known from Middle Cambrian strata in Utah. Recently, two new arachnomorphs (Dicranocaris Briggs, Lieberman, Hendricks, Halgedahl, and Jarrard, 2008 and Nettapezoura Briggs, Lieberman, Hendricks, Halgedahl, and Jarrard, 2008) were described from the Wheeler and Marjum formations of Utah. Cladistic analysis is undertaken to investigate arachnomorph relationships in light of these two new genera. The character matrix of Edgecombe and Ramsköld (1999) serves as the foundation for this study, augmented by new characters and taxa. The results of our cladistic analysis suggest that at least three distinct arachnomorph clades had diverged by the Middle Cambrian, and perhaps much earlier; the Utah genera can be referred to groups within one of these clades.

Identification of chitin in 200-million-year-old gastropod egg capsules

Paleobiology ◽  
10.1666/13083 ◽  
2014 ◽  
Vol 40 (4) ◽  
pp. 529-540 ◽  
Author(s):  
Marcin Wysokowski ◽  
Michał Zatoń ◽  
Vasilii V. Bazhenov ◽  
Thomas Behm ◽  
Andre Ehrlich ◽  
...  
Keyword(s):  
Analytical Methods ◽  
Fossil Record ◽  
First Record ◽  
Early Jurassic ◽  
Biological Macromolecules ◽  
High Input ◽  
Middle Cambrian ◽  
Fluvial Deposits ◽  
Egg Capsules ◽  
Holy Cross Mountains

Chitin occurs in a variety of invertebrates, especially in arthropod cuticles, but is rarely reported in the fossil record. Although it has been detected in fossils as old as Middle Cambrian and Silurian, the majority of records come from much younger, Cenozoic deposits. In this paper, we report the preservation of chitin in Early Jurassic neritimorph gastropod egg capsules deposited in bivalve shells from prodelta-deltafront and nearshore paleoenvironments of the Holy Cross Mountains, Poland. We used a number of analytical methods to confirm the presence of chitin preserved in these ancient fossils. This is the first record of chitin preservation in Mesozoic deposits that, interestingly, do not follow the conventional Konservat-Lagerstätten manner of preserving soft-bodied and non-biomineralized organisms. We believe that deltaic settings characterized by episodic, high input of fluvial deposits, oligohaline conditions, and oxygen-poor microenvironment within the sediment—as well as early cementation of sediment infilling the shells—were crucial for chitin preservation. The preservation of chitin in such recalcitrant structures as egg capsules and deposits that formed outside conventional Konservat-Lagerstätten conditions renders it likely similar deposits may yield promise for discoveries of similar biological macromolecules.

scholarly journals First record of intact equisetalean strobili from the Wealden (Lower Cretaceous) of the Isle of Wight, southern England

2021 ◽  
Vol 77 (1) ◽  
pp. 43-52
Author(s):  
Christian Pott
Keyword(s):  
Lower Cretaceous ◽  
Adventitious Roots ◽  
First Record ◽  
Plant Debris ◽  
Isle Of Wight ◽  
Southern England ◽  
Characteristic Morphology ◽  
Reproductive Structures ◽  
Fossil Genus

Two excellently preserved small strobili were obtained from a Wealden plant debris bed in the Lower Cretaceous (Barremian) Wessex Formation, south-east of Chilton Chine, on the Isle of Wight, southern England. The strobili are preserved as compressions and show the characteristic morphology of sporangiophore heads of Equisetales. Based on the morphology of the strobili, attribution to a certain species is not warranted. Therefore, the strobili have been left unassigned in the fossil-genus Equisetostachys which is commonly used for isolated strobili of fossil sphenophytes. From their size, shape and constitution, the strobili are interpreted as immature; the absence of preserved sporangia and spores is consequently not unexpected. Affiliation with Equisetum burchardtii might be an option. The strobili represent the first record of any equisetalean or sphenophyte remains from the Wessex Sub-basin of the English Wealden and are thus of considerable importance. The find is especially significant because previously known specimens from the Weald Sub-basin and the German Wealden are confined to subterranean rhizomes, adventitious roots, tubers and bases of aerial shoots, commonly preserved in situ, together with only fragmentary remains of sporangiophore heads from disarticulated strobili. These strobili finds are thus the first intact equisetalean reproductive structures from the Wealden of either England or Germany.

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