Bilaterian Burrows and Grazing Behavior at >585 Million Years Ago

  title={Bilaterian Burrows and Grazing Behavior at >585 Million Years Ago},
  author={Ernesto Pecoits and Kurt O. Konhauser and Natalie R. Aubet and Larry M. Heaman and Gerardo Veroslavsky and Richard A. Stern and Murray Gingras},
  pages={1693 - 1696}
Early Burrowers Direct fossil evidence of animals from Ediacaran period—the time in Earth's history just before extensive animal diversification in the Cambrian—is scant. However, the remains of animal activity in sediment, which remain intact through geologic time can provide clues about animal behavior and evolution. Pecoits et al. (p. 1693; see the Perspective by Droser and Gehling) found a suite of fossil animal burrows in sedimentary rocks in Uruguay. Radiometric dating places the age of… Expand
Discovery of the oldest bilaterian from the Ediacaran of South Australia
The fossil Ikaria wariootia is described, one of the oldest bilaterians identified from South Australia, and it is found that the size and morphology of Ikaria match predictions for the progenitor of the trace fossil Helminthoidichnites—indicative of mobility and sediment displacement. Expand
Ediacaran Ecosystems and the Dawn of Animals
Ichnology may provide remarkable information for our understanding of Ediacaran paleobiology, illuminating aspects such as the earliest evidence of bilaterians and the nature of Ediacaran ecosystems.Expand
At the Origin of Animals: The Revolutionary Cambrian Fossil Record
  • G. Budd
  • Biology, Medicine
  • Current genomics
  • 2013
Attention is now shifting to the period of time just before animals become common, at the base of the Cambrian and in the preceding Ediacaran Period. Expand
Infaunal augurs of the Cambrian explosion: An Ediacaran trace fossil assemblage from Nevada, USA.
The Dunfee assemblage records one of the oldest documented instances of sediment-penetrative infaunalization, corroborating previous molecular, ichnologic, and paleoecological data suggesting that crown-group bilaterians and bilaterian-style ecologies were present in late Ediacaran shallow marine ecosystems. Expand
The early Paleozoic development of bioturbation—Evolutionary and geobiological consequences
Abstract Bioturbation, the physical and chemical mixing of sediments by burrowing animals, is a critical engineering process in modern seafloor environments and exerts an important control on notExpand
Ocean oxygenation in the wake of the Marinoan glaciation
The data provide evidence for an early Ediacaran oxygenation event, which pre-dates the previous estimates for post-Marinoan oxygenation by more than 50 million years, and seem to support a link between the most severe glaciations in Earth’s history, the oxygenation of the Earth's surface environments, and the earliest diversification of animals. Expand
ABSTRACT Surface locomotory trace fossils from the Mistaken Point Formation of Newfoundland, dated at ∼ 565 Ma, suggest that organisms capable of controlled locomotion and possessing muscular tissueExpand
The rise and early evolution of animals: where do we stand from a trace-fossil perspective?
Critical, systematic and comprehensive evaluation of the Ediacaran–Cambrian trace-fossil record and high-resolution integration of the ichnological dataset and sedimentological information show that the advent of biogenic mixing was an important factor in fully marine environments at the dawn of the Phanerozoic. Expand
Ediacaran Marine Redox Heterogeneity and Early Animal Ecosystems
This study provides direct—rather than inferred—evidence that anoxia played a role in shaping a landmark Ediacaran ecosystem, if the anoxic conditions characteristic of the studied sections were widespread in the late Neoproterozoic, environmental stress would have hindered the development of complex ecosystems. Expand
Constraints on the timescale of animal evolutionary history
Calibrations for 88 key nodes across the phylogeny of animals, ranging from the root of Metazoa to the last common ancestor of Homo sapiens, are presented, highlighting the importance of identifying crown (not stem) fossils, levels of confidence in their attribution to the crown, current chronostratigraphic precision, the primacy of the host geological formation and asymmetric confidence intervals. Expand


Possible animal-body fossils in pre-Marinoan limestones from South Australia
The Neoproterozoic era was punctuated by the Sturtian (about 710 million years ago) and Marinoan (about 635 million years ago) intervals of glaciation. In South Australia, the rocks left behind byExpand
Fossil steroids record the appearance of Demospongiae during the Cryogenian period
It is suggested that shallow shelf waters in some late Cryogenian ocean basins contained dissolved oxygen in concentrations sufficient to support basal metazoan life at least 100 Myr before the rapid diversification of bilaterians during the Cambrian explosion. Expand
The Ediacaran emergence of bilaterians: congruence between the genetic and the geological fossil records
The two historical records of life both suggest that although the cradle of Metazoa lies in the Cryogenian, and despite the explosion of ecology that occurs in the Cambrian, it is the emergence of bilaterian taxa in the Ediacaran that sets the tempo and mode of macroevolution for the remainder of geological time. Expand
Giant Deep-Sea Protist Produces Bilaterian-like Traces
One of the strongest paleontological arguments in favor of the origin of bilaterally symmetrical animals (Bilateria) prior to their obvious and explosive appearance in the fossil record in the earlyExpand
Trace fossil preservation and the early evolution of animals
Abstract The trace fossil record is an important element in discussions of the timing of appearance of bilaterian animals. A conservative approach does not extend this record beyond about 560–555 Ma.Expand
First evidence for locomotion in the Ediacara biota from the 565 Ma Mistaken Point Formation, Newfoundland
Evidence for locomotion in the Precambrian fossil record is scant. Reliable Ediacaran trace fossils are all younger than 560 Ma, and consist of relatively simple horizontal burrows and trails fromExpand
Neonereites uniserialis from c. 600 Ma year old rocks in western Scotland and the emergence of animals
A chain of pellets (Neonereites uniserialis), usually attributed to a coelomate or pseudocoelomate metazoan, is described from the middle Dalradian Bonahaven Formation of western Scotland, inExpand
Pulsed oxidation and biological evolution in the Ediacaran Doushantuo Formation
High-resolution geochemical data from the fossil-rich Doushantuo Formation in South China are reported that confirm trends from other broadly equivalent sections and highlight key features that have not been observed in most sections or have received little attention. Expand
THE EDIACARA BIOTA: Neoproterozoic Origin of Animals and Their Ecosystems
Present evidence suggests that the Ediacara biota included a mixture of stem- and crown-group radial animals, stem-group bilaterian animals, “failed experiments” in animal evolution, and perhaps representatives of other eukaryotic kingdoms. Expand
The Paleoproterozoic megascopic Stirling biota
Abstract The 2.0–1.8-billion-year-old Stirling Range Formation in southwestern Australia preserves the deposits of a siliciclastic shoreline formed under the influence of storms, longshore currents,Expand