|
Heliomedusa
Mickwitziids are a Cambrian group of shelly fossils with originally phosphatic valves, belonging to the Brachiopod stem group, and exemplified by the genus ''Mickwitzia'' – the other genera are ''Heliomedusa'' (a possible junior synonym of ''Mickwitzia''?) and ''Setatella''. The family Mickwitziidae is conceivably paraphyletic with respect to certain crown-group brachiopods. Shell microstructure Punctae or tubes penetrate through multiple shell wall layers, and individual punctae often develop a single, axial phosphatic tube. The shell comprises multiple phosphatic laminae; the region closest to the edge of the shell was presumably more organic-walled than phosphatized as it tends to be more flimsily preserved. Members of the genus appear to share characteristic shell microstructure in common with Tommotiids such as ''Micrina'', and like this taxon, mickwitziids may not have been able to enclose their entire body within a bivalved shell. The shells are punctuated with in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliomedusa
Mickwitziids are a Cambrian group of shelly fossils with originally phosphatic valves, belonging to the Brachiopod stem group, and exemplified by the genus ''Mickwitzia'' – the other genera are ''Heliomedusa'' (a possible junior synonym of ''Mickwitzia''?) and ''Setatella''. The family Mickwitziidae is conceivably paraphyletic with respect to certain crown-group brachiopods. Shell microstructure Punctae or tubes penetrate through multiple shell wall layers, and individual punctae often develop a single, axial phosphatic tube. The shell comprises multiple phosphatic laminae; the region closest to the edge of the shell was presumably more organic-walled than phosphatized as it tends to be more flimsily preserved. Members of the genus appear to share characteristic shell microstructure in common with Tommotiids such as ''Micrina'', and like this taxon, mickwitziids may not have been able to enclose their entire body within a bivalved shell. The shells are punctuated with in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terreneuvian
The Terreneuvian is the lowermost and oldest series of the Cambrian geological system. Its base is defined by the first appearance datum of the trace fossil ''Treptichnus pedum'' around million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around million years ago.PENG, S.C. & BABCOCK, L.E. 2011. Continuing progress on chronostratigraphic subdivision of the Cambrian System. Bulletin of Geosciences 86(3), 391–396 (1 figure). Czech Geological Survey, Prague. . This series' name was formally accepted by the International Commission on Stratigraphy in 2007. The Fortunian stage and presently unnamed Cambrian Stage 2 are the stages within this series. The Terreneuvian corresponds to the pre- trilobitic Cambrian. The name Terreneuvian is derived from ''Terre Neuve'', the French name for the island of Newfoundland, Canada, where many rocks of this age are found, including the type section. Type locality The type locality (GSSP) of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Brachiopod Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1969
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Life Of Alberta
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
