Biomineralized skeletons are widespread in animals, and their origins can be traced to the
latest Ediacaran or early Cambrian fossil record, in virtually all animal groups. The origin of …

Deuterostomes are the major division of animal life which includes sea stars, acorn worms,
and humans, among a wide variety of ecologically and morphologically disparate taxa …

Dating the tree of life is a core endeavor in evolutionary biology. Rates of evolution are
fundamental to nearly every evolutionary model and process. Rates need dates. There is …

Sea cucumbers (Holothuroidea) are a morphologically diverse, ecologically important, and
economically valued clade of echinoderms; however, the understanding of the overall …

Data on the first appearances of major animal groups with mineralized skeletons on the
Siberian Platform and worldwide are revised and summarized herein with references to an …

Echinoderms are a major group (phylum) of invertebrate animals with a rich fossil record
stretching back to the Cambrian period, approximately 518 million years ago. While all …

Microbial carbonates were major components of early Paleozoic reefs until coral-
stromatoporoid-bryozoan reefs appeared in the mid-Ordovician. Microbial reefs were …

Echinoids are key components of modern marine ecosystems. Despite a remarkable fossil
record, the emergence of their crown group is documented by few specimens of unclear …

Formal subdivision of the Cambrian System into four series and ten stages is in progress.
The base of Cambrian Stage 3 (provisional), which is conterminous with the base of …

An assemblage of mineralised skeletal fossils containing molluscs, hyoliths, halkieriids,
chancelloriids, tommotiids, lobopodians, paleoscolecids, bradoriids, echinoderms …