The fossil record of plant origins

Cryptospores are spore-like microfossils found in lower Palæozoic rocks. They typically form polyads with 2, 4, or more cells more-or-less permanently attached. Some have been described from sporangia of Siluro-Devonian plants; the vast majority, however, are found freely dispersed in shallow marine or non-marine sediments without connection to parent plants or algae. Because cryptospores occur in rocks that pre-date the first occurrence of macroscopic plant fossils, they represent our best fossil evidence for the evolution of land plants from their streptophyte algal ancestors.

Cryptospores: Definition
The term, cryptospore, was first defined by Richardson, Ford & Parker (1984) who erected the Anteterma: Cryptosporites to accommodate spore-like remains that seemed morphologically related to trilete spores, but whose proximal faces were obscured by continued attachment in spore tetrads and dyads. 
This webpage contains an image collection of cryptospore holotype, syntypes and related examples of cryptospore species erected between 1979 and 2017. (work in progress)
Cambrian Cryptospores
Shales of the Bright Angel Shale in the Grand Canyon contain a well-preserved suite of cryptospores and other microscopic organic remains. See Strother et al. 2004; Baldwin et al. 2008; Taylor & Strother, 2008 for more information.
Contact Information
 +1 617 552 8395

Paul K Strother
Department of Earth & Environmental Sciences
Weston Observatory of Boston College
381 Concord Road
Weston MA 02493