Cambrian mass extinction is when species vanish much faster than they are replaced. Some reasons led to mass extinction some million years back (Lozano-Fernandez et al., 2020). First, there was a wide range of both animal and plant death from marine organisms to enormous dinosaurs; hence species go extinct all the time. Secondly, the evaluation of species during the Cambrian time also led to mass extinction. Thirdly, about 575 million years ago, microscopic animals appeared, which diverted 24 million years later, leading to Cambrian mass extinction.
A landmass is a large land area surrounded by an ocean or sea. On the other hand, Euramerica is a minor super continental created in the Devonian due to the collision between the Laurentian and Baltica. Euramerica was formed by joining the two earlier continents Laurentia and Baltica (Krause et al., 2018). Avanolia, Laurentia, and Baltica came together to form Euramerica, leading to the impetus ocean closure. The collision led to the northern Appalachians formation. Euramerica sat near Siberia, and the Khanty Ocean was found between them. During these events, Gondwana moved gradually towards the South Pole. Most of the Euramerican landmass are referred to old red sandstone continent. Euramerica is made up of northwest Africa and southwest Europe, and it is located slightly to the lower latitude.
Acadian Orogeny is a long-lasting mountain building from middle Devonian to late Devonian. Acadian Orogeny began roughly around 375 million years ago, and it was active for 50 million years (Lozano-Fernandez et al., 2020). It is located as the third among the four orogenies that created the basin. Geographically, Acadian Orogeny extended from the Canadian marine provinces towards the Southwesterly direction to Alabama. The formation that led to the collision of the Acadian orogeny resulted in the shape of mountain belts. Acadian orogeny is caused by landmass collision with other landmasses and the overriding of oceanic ridges by the continent. This mountain building incident impacted a region from modern-day New York during the Devonian period. Initially, a depositional fore-arc basin resulted from the compressional orogenic activity.
The first seed-bearing from the Devonian period is called the seed fern, and it produces its seeds on its leaves without a unique structure. They are also known as phonograms, meaning they create their seeds (Krause et al., 2018). These plants have hidden sexual organs that are the reason behind the name phonograms. True seed fern became more numerous and diverse during the Carboniferous period; Seed ferns gave rise to the gymnosperm during the palaeozoic period. Gymnosperms such as conifers inhabit many ecosystems because they are well adapted to the cold weather.
A calcite sea is where low magnesium calcite is the primary inorganic marine calcium carbonate precipitate. An organic ocean is seawater that organizes, and highly magnesium calcite is the direct inorganic carbonate participants (Lozano-Fernandez et al., 2020). Early and late Paleozoic oceans were predominantly Calcite Sea, while the middle Paleozoic is characterized by organic sea. Effect of calcite sea condition includes the formation of carbonate, which spreads highly on the hard ground and calcite types of cement. Complex environments were pervasive in the calcite sea. Calcite seas coincided with the time of rapid seafloor spreading and greenhouse climate conditions. The outer shell of calcite and inner body of aragonite or skeletons and thick calcite shells always dominate invertebrate organisms’ fossils in calcite sea deposits. That apparently happened since aragonite dissolved fast on the seafloor and called for protection or avoidance as a biomineral.
Exceptionally preserved fossils biotas of the Burgess shales and a handful of other similar Cambrian deposits provide rare but critical insight into the early diversification of animals. The extraordinary preservation of label tissues in this geographical widespread but temporarily restricted soft-bodied fossils assemblages has remained enigmatic since 1909 (Lozano-Fernandez et al., 2020). Here we demonstrate the mechanism of Burgess shale type preservation using sedimentologic and geochemical data from the Chengjiang, Burgess shale, and other principal Burger shell resulting from early inhibition of microbial activities in the sediments by means deprivation of low sulfate concentration in the global ocean and common oxygen bottom water condition at the site of deposition resulted into reduced oxidant reduction.
Lozano-Fernandez, J., Tanner, A. R., Puttick, M. N., Vinther, J., Edgecombe, G. D., & Pisani, D. (2020). A Cambrian–Ordovician terrestrialization of arachnids. Frontiers in genetics, 11, 182.
Krause, A. J., Mills, B. J., Zhang, S., Planavsky, N. J., Lenton, T. M., & Poulton, S. W. (2018). Stepwise oxygenation of the Paleozoic atmosphere. Nature Communications, 9(1), 1-10.