A cosmopolitan late Ediacaran biotic assemblage: new fossils from Nevada and Namibia support a global biostratigraphic link

Owing to the lack of temporally well-constrained Ediacaran fossil localities containing overlapping biotic assemblages, it has remained uncertain if the latest Ediacaran ( ca 550–541 Ma) assemblages reflect systematic biological turnover or environmental, taphonomic or biogeographic biases. Here, we report new latest Ediacaran fossil discoveries from the lower member of the Wood Canyon Formation in Nye County, Nevada, including the first figured reports of erniettomorphs, Gaojiashania , Conotubus and other problematic fossils. The fossils are spectacularly preserved in three taphonomic windows and occur in greater than 11 stratigraphic horizons, all of which are below the first appearance of Treptichnus pedum and the nadir of a large negative δ 13 C excursion that is a chemostratigraphic marker of the Ediacaran–Cambrian boundary. The co-occurrence of morphologically diverse tubular fossils and erniettomorphs in Nevada provides a biostratigraphic link among latest Ediacaran fossil localities globally. Integrated with a new report of Gaojiashania from Namibia, previous fossil reports and existing age constraints, these finds demonstrate a distinctive late Ediacaran fossil assemblage comprising at least two groups of macroscopic organisms with dissimilar body plans that ecologically and temporally overlapped for at least 6 Myr at the close of the Ediacaran Period. This cosmopolitan biotic assemblage disappeared from the fossil record at the end of the Ediacaran Period, prior to the Cambrian radiation.

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Biogeography and the nature and timing of the Cambrian radiation

The Paleontological Society Papers ◽

10.1017/s1089332600002357 ◽

2004 ◽

Vol 10 ◽

pp. 79-92 ◽

Cited By ~ 2

Author(s):

Bruce S. Lieberman ◽

Joseph G. Meert

Keyword(s):

Fossil Record ◽

Early Cambrian ◽

Limited Evidence ◽

Population Densities ◽

Biogeographic Patterns ◽

Molecular Studies ◽

History Of ◽

Cambrian Radiation ◽

The One ◽

Biogeographic Analysis

Biogeographic patterns from early Cambrian trilobites are used to evaluate the nature and timing of the Cambrian radiation. Results from a phylogenetic biogeographic analysis reveal that patterns of vicariance are compatible with a vicariant distribution of trilobites across what were originally joined elements of the supercontinent Pannotia; further, there is limited evidence for coordinated range expansion or geo-dispersal by these trilobites. As Pannotia had split apart sometime between 550-600 Ma this suggests that trilobites, and by extension several other metazoan taxa, had begun to diversify by this interval. This result suggests that there may have been some period of cryptic diversification by metazoans prior to the Cambrian radiation, though the inferred length of this interval is not as long as that invoked by some molecular studies. Perhaps trilobites existed at low population densities in marginal environments before they became paleontologically emergent. Even though the results suggest some apparent gap in the fossil record, the evolutionary signature of this gap is still preserved in the paleobiological patterns from the fossil record, indicating that the fossil record is still the one best source of data on the nature of key episodes in the history of life, like the Cambrian radiation.

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An Expansion of Age Constraints for Microbial Clades that Lack a Conventional Fossil Record Using Phylogenomic Dating

Journal of Molecular Evolution ◽

10.1007/s00239-011-9467-y ◽

2011 ◽

Vol 73 (3-4) ◽

pp. 188-208 ◽

Cited By ~ 8

Author(s):

Carrine E. Blank

Keyword(s):

Fossil Record ◽

Age Constraints

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Earth History Change: The Pacemaker of Evolution

The Paleontological Society Papers ◽

10.1017/s1089332600001212 ◽

2005 ◽

Vol 11 ◽

pp. 5-14 ◽

Cited By ~ 1

Author(s):

Bruce S. Lieberman

Keyword(s):

Geographic Information Systems ◽

Fossil Record ◽

Parsimony Analysis ◽

Earth History ◽

Geographic Space ◽

History Of ◽

Cambrian Radiation ◽

Time Periods ◽

The Relationship ◽

Biogeographic Analysis

Paleobiogeography is the discipline that aims to uncover correlations between Earth history (geological and climatic) change and evolution by focusing on how biotas evolve across geographic space. Phylogenetic biogeographic methods applied to fossil taxa, especially those methods based on a modified version of Brooks Parsimony Analysis, have shown potential for uncovering the relationship between Earth history change and evolution. Two processes have an important role in shaping the evolution of biotas across geographic space: these are vicariance and geodispersal. Approaches to biogeographic analysis in the fossil record have uncovered evidence linking some of the key episodes in the history of life, including the Cambrian radiation, to the major geological changes that were occurring at the time. They also have shown that in different time periods with different Earth history signatures the corresponding evolutionary and biogeographic signatures are different. Promising new areas in paleobiogeography include expanded application of phylogenetic approaches and the use of Geographic Information Systems.

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Eocene Loranthaceae pollen pushes back divergence ages for major splits in the family

PeerJ ◽

10.7717/peerj.3373 ◽

2017 ◽

Vol 5 ◽

pp. e3373 ◽

Cited By ~ 11

Author(s):

Friðgeir Grímsson ◽

Paschalia Kapli ◽

Christa-Charlotte Hofmann ◽

Reinhard Zetter ◽

Guido W. Grimm

Keyword(s):

Fossil Record ◽

Middle Miocene ◽

Molecular Data ◽

Late Eocene ◽

Molecular Dating ◽

The Family ◽

Minimum Age ◽

Age Constraints ◽

Scanning Electron ◽

Lineage Diversification

BackgroundWe revisit the palaeopalynological record of Loranthaceae, using pollen ornamentation to discriminate lineages and to test molecular dating estimates for the diversification of major lineages.MethodsFossil Loranthaceae pollen from the Eocene and Oligocene are analysed and documented using scanning-electron microscopy. These fossils were associated with molecular-defined clades and used as minimum age constraints for Bayesian node dating using different topological scenarios.ResultsThe fossil Loranthaceae pollen document the presence of at least one extant root-parasitic lineage (Nuytsieae) and two currently aerial parasitic lineages (Psittacanthinae and Loranthinae) by the end of the Eocene in the Northern Hemisphere. Phases of increased lineage diversification (late Eocene, middle Miocene) coincide with global warm phases.DiscussionWith the generation of molecular data becoming easier and less expensive every day, neontological research should re-focus on conserved morphologies that can be traced through the fossil record. The pollen, representing the male gametophytic generation of plants and often a taxonomic indicator, can be such a tracer. Analogously, palaeontological research should put more effort into diagnosing Cenozoic fossils with the aim of including them into modern systematic frameworks.

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Lessons from the fossil record: the Ediacaran radiation, the Cambrian radiation, and the end-Permian mass extinction

Marine Biodiversity and Ecosystem Functioning ◽

10.1093/acprof:oso/9780199642250.003.0005 ◽

2012 ◽

pp. 52-72 ◽

Cited By ~ 4

Author(s):

Stephen Q. Dornbos ◽

Matthew E. Clapham ◽

Margaret L. Fraiser ◽

Marc Laflamme

Keyword(s):

Mass Extinction ◽

Fossil Record ◽

Cambrian Radiation ◽

Permian Mass Extinction

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New phylogenetic insights into the Cambrian radiation of arachnomorph arthropods

Journal of Paleontology ◽

10.1666/07-017.1 ◽

2008 ◽

Vol 82 (3) ◽

pp. 585-594 ◽

Cited By ~ 26

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.

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Developmental Capacity and the Early Evolution of Animals

Journal of the Geological Society ◽

10.1144/jgs2020-245 ◽

2021 ◽

pp. jgs2020-245

Author(s):

Douglas H. Erwin

Keyword(s):

Molecular Clock ◽

Adaptive Radiation ◽

Fossil Record ◽

Early Evolution ◽

Cambrian Explosion ◽

Developmental Studies ◽

Content Type ◽

Developmental Capacity ◽

Cambrian Radiation ◽

Morphological Novelties

Disentangling the factors underlying the appearance of macroscopic, often skeletonized, bilaterians during the Ediacaran-Cambrian diversification of animals requires carefully parsing the contributions of ecological opportunity, environmental potential and developmental capacity. The early evolution of animals involved the introduction of genomic, developmental, morphologic and behavioral novelties, identified as the individuation of new characters, which led to the construction of new ecological networks (innovation). Here I employ a recently introduced conceptual framework for novelty and individuation that distinguishes between potentiation, novelty, innovation and adaptive adjustments to the Ediacaran-Cambrian radiation, and focus on the roles of potentiation and novelty in the expansion of developmental capacity. Comparative developmental studies combined with molecular clock estimates and data from the fossil record suggest that developmental capacity, the potential to generate a range of morphologies, may expand rapidly through developmental novelties without leading directly to morphological novelties, or to innovation. The expected patterns from this framework are markedly different from those in adaptive radiation scenarios.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosion

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The unique fossil assemblage from the Lode Quarry (Upper Devonian, Latvia)

Fossil Record ◽

10.5194/fr-4-101-2001 ◽

2001 ◽

Vol 4 (1) ◽

pp. 101-119 ◽

Cited By ~ 10

Author(s):

I. Upeniece

Keyword(s):

Fossil Record ◽

Juvenile Fish ◽

Upper Devonian ◽

Ontogenetic Change ◽

Fossil Assemblage ◽

Unique Data ◽

Parasitic Association ◽

Main Devonian Field ◽

Lower Frasnian ◽

Parasitic Platyhelminth

The unique fossil fauna from the Lode clay quarry, lower Frasnian, Latvia, includes a diverse ichthyofauna of at least 15 taxa of agnathans and gnathostomes, representing most of the major taxa of Devonian vertebrates. Six new fish taxa (five species and one genus) were discovered during the last ten years. Exceptionally well-preserved juvenile fishes (Asterolepis ornata, Lodeacanthus gaujicus) provide unique data on ontogenetic change. Diverse arthropods are recorded. Parasitic platyhelminth remains in juvenile fish bodies is their first discovery in the fossil record, and represents the oldest parasitic association ever found. A complete faunal and floral list for the Lode quarry is presented, with a detailed biostratigraphic section. Comparison of vertebrata taxa from the Gauja Regional Stage with similar of the Main Devonian Field, Scotland, Timan, Canada, and Germany is reviewed. Die einzigartige Lebensgemeinschaft von Lode repräsentiert eine diverse Fischfauna nahezu aller Hauptwirbeltiertaxa, die im Devon lebten. Sechs neue Fischtaxa (5 Arten und 1 Gattung) wurden in den letzten zehn Jahren in den Unter-Frasnium-Schichten der Ziegeleigrube von Lode in Lettland entdeckt. Insgesamt sind 15 identifizierte und unbestimmte Fisch- und Agnathen-Arten von dort bekannt. Besondere Beachtung wurde den außergewöhnlich gut erhaltenen Jugendformen von Asterolepis ornata und Lodeacanthus gaujicus und verschiedenen Invertebraten (Crustacea, Merostomata) gespendet, die in einer einzigen Linse fein verteilten Tones gefunden wurden. Reste parasitischer Platyhelminthen, die in Jungfischen auftreten, wurden hier zum ersten Mal als Fossilien entdeckt; sie repräsentieren die älteste bisher gefundene parasitische Gemeinschaft. Eine Liste der organischen Reste aus den Schichten der Ziegeleigrube Lode wird präsentiert. Ein detailliertes biostratigraphisches Profil wird beschrieben. Die Fischfaunen aus der Gauja Regional-Stufe werden mit denen vom Hauptdevonfeld Russlands, von Schottland, dem Timan, Kanadas und Deutschlands verglichen. <br.> doi:<a href="http://dx.doi.org/10.1002/mmng.20010040108" target="_blank">10.1002/mmng.20010040108</a>

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Conidae and Terebridae (Gastropoda: Neogastropoda) from the Plio-Pleistocene of the Philippines

Zootaxa ◽

10.11646/zootaxa.4221.5.4 ◽

2017 ◽

Vol 4221 (5) ◽

pp. 545 ◽

Cited By ~ 1

Author(s):

ENATE A. HELWERDA

Keyword(s):

Species Composition ◽

Deep Water ◽

Fossil Record ◽

The Philippines ◽

Fossil Assemblage ◽

Fossil Assemblages ◽

Eleven Species ◽

Lack Of Knowledge

Six species of Conidae and seven species of Terebridae are reported from the Plio-Pleistocene “Cabarruyan” fauna of Pangasinan, the Philippines. Eleven species are identified; these species all occur in the Recent Indo-Pacific fauna and seven of these are previously known from the fossil record as well. The species composition of this fauna shows little overlap with other fossil assemblages, except with the Fijian fossil assemblage. This is attributed to a lack of knowledge on Indo-pacific fossil faunas as well as to the relatively deep water setting (200–300 m) of this fauna. More research is needed to determine why the Fijian assemblage is relatively similar.

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