Animal origins: The record from organic microfossils

Accumulated records of organic microfossils span billions years Earth history. The majority this record consists prokaryotes plus eukaryotes a protistan grade, yet type fossilisation is also capable capturing the organically preserved remains animals. Recently, it has become apparent that non-biomineralizing animal groups, otherwise known only from rare instances exceptional fossilisation, can preserve in fashion. Given high taphonomic fidelity combined with temporal continuity microfossil preservation, clear style potential to circumvent some major biases afflict current early fossil record. Despite this, there have been no attempts survey recorded animal-derived microfossils. We constructed global database comprising 394 studies covering 399 sedimentary rock formations spanning Tonian–Cambrian Stage 5/Wuliuan (1 Ga 505 Ma). consolidates scattered reports and provides first appraisal for how metazoans emerges within broader archives Scrutiny reveals contain oldest body evidence number key metazoan clades, including Chaetognatha, Annelida, Priapulida, ‘lobopods’ Panarthropoda, Crustacea, Pterobranchia, potentially even Bilateria. Also detected among are fossilised poriferans, chancelloriids, palaeoscolecids, loriciferans, bradoriids, trilobites, wiwaxiids, molluscs, hyoliths, brachiopods chordates. Our data shows metazoan-derived relatively common constituents palynological preparations sediments Cambrian age or younger. Such assemblages several late Ediacaran age, but entirely absent large equivalent older sediments, throughout Proterozoic. In view, signs diversification emerge as unidirectional signal embedded deeper argue here absence Tonian, Cryogenian strata weakens case existence cryptic biosphere during Tonian Cryogenian.