Mesoproterozoic Era

What happened during this time? 

Geophysical

• This time is marked by robust tectonic activity 

  • The breakup of the supercontinent Columbia (Zhao et al., 2004) 

  • Formation of the supercontinent Rodinia (Li et al., 2008).

• Oxygen levels were originally thought to be too low, but evidence indicates that they were 3.7% of current levels (Park et al., 2025)

• Earth’s atmosphere contained 10X more carbon dioxide than today (Park et al., 2025)

Biological

• Maximum diversity of stromatolites

• Clear evidence of photosynthetic eukaryotes on Earth

• Origin of major groups, such as the red and green algae, and clear evidence of their ability to become multicellular (Knoll et al., 2006; Bai, 2015). 

• The red algae or rhodophytes probably originated by at least 1.6 Ga, and the green alga lineage probably originated by 1.5 Ga (Yoon et al., 2004)

  • Rafatazmia † and Ramnathallus †, are two genera from 1.6 Ga with features aligning them with rhodophytes (Bengtson et al., 2017)

  • The earliest fossils attributed to green algae from the Stenian-Ectasian boundary at 1,200 Ma (Tappan, 1980; Knoll, 2003). The nature of these early fossils is controversial (Cavalier-Smith, 2006)

• All major algal groups were present by at least the late Mesoproterozoic (Taylor et al., 2009).