Related Experiment Video
Updated: Jan 30, 2026

A Treatment Package without Escape Extinction to Address Food Selectivity
Published on: August 21, 2015
A Cambrian soft-bodied biota after the first Phanerozoic mass extinction
Han Zeng1,2, Qi Liu3, Fangchen Zhao4,5
1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China.
None:
Cambrian Burgess Shale-type (BST) fossil biotas document nearly complete snapshots of the oldest Phanerozoic marine ecosystems1-4. However, the rarity of deposits bearing high-diversity BST biotas5 has restricted our understanding of the evolutionary and ecological dynamics of the Cambrian explosion. Here we report the Huayuan biota-a lower Cambrian (Stage 4, approximately 512 million years ago) BST Lagerstätte from an outer shelf, deep-water setting of the Yangtze Block in Hunan, South China. The Huayuan biota yields remarkable taxonomic richness, comprising 153 animal species of 16 phylum-level clades dominated by arthropods, poriferans and cnidarians, among which 59% of species are new. The biota is comprised overwhelmingly of soft-bodied forms that include preserved cellular tissues. The complex ecosystem contained diverse radiodonts and pelagic tunicates, filling a gap of high-diversity BST biotas from the Cambrian Stage 4. Critically, multivariate ordination based on a global dataset of Cambrian BST biotas places the Huayuan biota within a main transition of marine animal ecosystems between Cambrian Age 3 and Age 4. Network analysis reveals close faunal connections between the Huayuan and Burgess Shale biotas, indicating transoceanic dispersal. Dated shortly after the Sinsk event6-8, the Huayuan biota illuminates differences in the impacts of this extinction in shallow- versus deep-water settings during the first Phanerozoic mass extinction and offers critical insights into the transformation of global ecosystems in the early Cambrian.
Related Concept Videos
Reduced Mass Coordinates: Isolated Two-body Problem
Generalization, Discrimination, and Extinction
Generalization occurs when a behavior reinforced in one context is performed in similar situations. For instance, a student who studies diligently for calculus and receives excellent grades might apply the same study habits to psychology and history, expecting similar results. Generalization shows how learning in one setting can influence behavior in...
Atomic Mass
Molar Mass
Body Temperature
Body Temperature
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C...

