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Very few Archean stromatolites contain fossilized microbes, but fossilized microbes are sometimes abundant in Proterozoic stromatolites. [ 16 ] While features of some ancient apparent stromatolites are suggestive of biological activity, others possess features that are more consistent with abiotic (non-biological) precipitation. [ 17 ]
The fossil history of flowering plants records the development of flowers and other distinctive structures of the angiosperms, now the dominant group of plants on land.The history is controversial as flowering plants appear in great diversity in the Cretaceous, with scanty and debatable records before that, creating a puzzle for evolutionary biologists that Charles Darwin named an "abominable ...
The Gunflint Iron Formation is a banded iron formation, composed predominantly of dense chert and slate layers interbedded with ankerite carbonate layers. The chert layers can be subdivided into black layers (containing organic material and pyrite), red layers (containing hematite), and green layers (containing siderite). [5]
In 1881, John Evans recognized that use of copper often preceded the use of bronze, and distinguished between a transitional Copper Age and the Bronze Age proper. He did not include the transitional period in the Bronze Age, but described it separately from the customary stone / bronze / iron system, at the Bronze Age's beginning.
The Neogene (/ ˈ n iː. ə dʒ iː n / NEE-ə-jeen, [6] [7]) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.04 million years ago to the beginning of the present Quaternary Period 2.58 million years ago.
The identification of plant fossils in Cambrian strata is an uncertain area in the evolutionary history of plants because of the small and soft-bodied nature of these plants. It is also difficult in a fossil of this age to distinguish among various similar appearing groups with simple branching patterns, and not all of these groups are plants.
Category: Neogene plants. 4 languages. ... Prehistoric plants of the Neogene Period, during the Middle Cenozoic Era Subcategories. This category has the following 2 ...
The Siderian Period (/ s aɪ ˈ d ɪər i. ə n, s ɪ-/; Ancient Greek: σίδηρος, romanized: sídēros, meaning "iron") is the first geologic period in the Paleoproterozoic Era and lasted from 2500 Ma to 2300 Ma. Instead of being based on stratigraphy, these dates are defined chronometrically.