BIOLOGY 230 Lecture Notes - Lecture 1: Rhynie Chert, Rhynia, Cooksonia
Document Summary
Cambrian period: time of increased multicellularity and formation of hard-shelled fossils (think triloibites), but life restricted to the seas. Extinct land plants- the fossil record: cambrian period: 540-505 mya time of increased multicellularity and formation of hard-shelled fossils (think triloibites), but life restricted to the seas, ordovician period: 505-440 mya. Silurian period: 440-410 mya: cooksonia fossils are seen in the mid-silurian growing close to water simple, stick-like, lea ess plants. The oldest known vascular plant, cooksonia, consisted of dichotomously branching axes. This fossil, found in shropshire, england, is from the late. Its lea ess aerial stems are 2. 5 centimeters high, and they terminate in sporangia, or spore-producing structures. These small plants, which grew no higher than 6. 5 centimeters, probably lived in moist environments such as mud ats: devonian 410-360 mya. Early devonian period (410 - 390 mya: rhynia seen in the early devonian (rhynie chert fossil) is more complex than cooksonia.
