Furongian Epoch

Furongian is an epoch that occurs after Series 3 (Cambian), and before the Tremadocian (Early Ordovician).

What happened during this time?

Seafloor substrate was beginning to change
The start of the Caledonian orogeny which will create new mountain ranges extending from present-day Scandinavia through Britain and into North America

Algal mats penetrated the interstices between sediment particles, fixing and stiffening the sea bottom.
By the late Cambrian, metazoans had affected this mat. Some parts are beginning to resemble the loose, muddy, and unconsolidated sea floor.
The rate of weathering on land also increased
Larger, superficially more advanced trilobites of the Middle Cambrian disappeared in this new, muddier world.
By contrast, the tiny agnostids trilobites were well equipped to dig into -- and out of -- the loosened substrate
Paleobiodiversity curves indicate that the Cambrian Explosion and the Great Ordovician Biodiversity Event (GOBE) are either two clearly distinguishable ‘events’ or that they both belong to a single, continuous radiation (e.g., Alroy et al., 2008)
The late Cambrian ‘Furongian Gap,’ which is visible between the Cambrian Explosion and the GOBE, is possibly only due to a sampling artifact because upper Cambrian sediments are relatively rare and paleontological investigations on this interval, sporadic (Harper et al., 2019).

There is currently no evidence of plants macrofossils, but microfossils in the form of cryptospores exist in Cambrian sediments.

Taylor & Strother, 2009
Cryptospores, spherical to discoidal in shape
They are simple and thick-walled, enclosed within a packet characterized by a common envelope (synoecosporal wall)
Each packet contains 1-8 cells, typically 1 or 2 paired cells (dyads)
Packets may be solitary or occur in closely connected dyads, tetrads, or larger aggregated clusters
These fossils exhibit "...an intermediate condition between the algae and the embryophytes"
It appears that a land-based Coleochaete-like alga (cryptophyte) produced these thick-walled spores for use in an aerial (non-aquatic) environment