GLGY 307 Lecture Notes - Lecture 14: Stromatolite, Archaeocyatha, Craton
26 Dec 2017
School
Department
Course
Professor
Document Summary
Eidacara fauna discovery: rawnsley quartzite, uppermost part of the proterozoic often referred to as ediacarian. Ediacara fauna extinction: ediacara fauna appeared ~630 million years ago and developed for about 50 million years. It represents the first adaptive radiation of the multicellular organisms: fossil record is patchy, last record: ireland ~510 million years ago. Significance of the earlier trace fossils: the early cambiran is not a homogeneous stratigraphic interval when we consider the organic debris recorded throughout the world, 5 intervals are recognized, toyonian, botomian, atdabanian, tommotian, nemakit-daldynian. Earliest shelly animals: the earliest shelly animals are known from the latest neoproterozoic of namibia (sw africa) First abundant shelly faunas: the earliest true faunas consisting of serveral genera and species that present well-developed shells are known from the early cambrian (tommotian stage, they are small-sized, some of them being calcareous, some phophatic in nature.
