Cambrian’s explosion occurred millions of years earlier than we thought previously: study
Paleontologists have analyzed bodily profiles from Ediacaran-Cambrian organizations using fossil traces as body fossil indicators.
A reconstruction of the life of the early Cambrian Ocean in southern China. Image credit: Dongjing Fu.
The so-called explosion of Cambrian is generally labeled as the time in the history of the earth when the planes of the animal body suddenly appear.
Most studies suggest that this event occurred between 541 million and 530 million years at the start of the Cambrian period.
“The Cambrian explosion is a unique period in the history of life that poses many unanswered questions,” said Dr. Olmo Miguez Salas of Universitat Barcelona and Dr. Zekun Wang of the Natural History Museum, London.
“To dive into the biodiversity of this period, most of the studies in paleontology tend to focus on the study of organizations that had difficult parts.”
“However, the study of fossil traces opens up the possibility of discovering what the activity of organisms with a hard body, with soft or skeletal body preserved in the stratigraphic file was like.”
“The fossil trace file provides valuable information over evolving periods when the soft body fauna was dominant.”
“The fossil traces reflect the behavior of the organism that generates them, which is determined by the habitat and the responses to environmental stimuli.”
“Consequently, they are an indicator of the paleoecological conditions in which the organizations that generated them lived.”
In their study, the authors focused on the traces of fossil in the transition from Ediacaran-Cambrien, a period of recognized paleoevolutionary interest which was a turning point in the evolution of complex life on earth.
In this transition, there was a radical change in biodiversity and in the structure of organisms and ecosystems.
“Ediacaran’s fauna was dominated by complex and multicellular organisms with soft body,” said Dr. Miguez Salas.
“The transition to Cambrian involved the extinction of a large part of the ediacara fauna and a rapid diversification of complex multicellular life forms with hard parts (for example, exoskeletons).”
“This is the evolutionary nucleus from which most modern animals have emerged: what is called the Cambrian explosion.”
The results show that organizations with thin bodily profiles prospered approximately 545 million years ago (Ediacaran period).
“These organisms probably have coelomic hydrostatic bodies, with an anteroposterior axis, muscles and possibly segmentation,” said Dr. Miguez Salas.
“In addition, these organizations could move in a specific direction (directional locomotion) and probably possessed sensory capacities to move and feed on heterogeneous substrates in a habitat dominated by microbial carpets.”
“Consequently, the so -called Cambrian explosion and its scalable implications may have occurred much earlier than the estimate.”
“These adaptations in the bodily profile and mobility allowed the first animals to prosper in increasingly dynamic and complex environments, an ecological engineering which could promote evolutionary innovations.”
The team newspaper appears in the newspaper Geology.
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Zekun Wang and Olmo Miguez-Salas. Quantitative decoding of fossil morphologies of ediacaran tray trace: Evidence of the emergence of anterior-post-posterior thin profiles. Geologypublished online on June 9, 2025; DOI: 10.1130 / G53332.1
