Structure and development of early multicellular organisms
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The Precambrian dates from around 3850 to 542 million years ago. The Neoproterozoic is characterized by a large glaciation event, followed by the appearance of the first multicellular body plans before the Cambrian Explosion.
Until the late 1950s, the Precambrian was not believed to have hosted multicellular organisms. However, with radiometric dating techniques, it has been found that fossils initially found in the Ediacara Hills in Southern Australia date back to the late Precambrian. These fossils are body impressions of organisms shaped like disks, fronds and some with ribbon patterns that were most likely tentacles.
These are the earliest multicellular organisms in Earth's history, despite the fact that unicellularity had been around for a long time before that. The requirements for multicellularity were embedded in the genes of some of these cells, specifically choanoflagellates. These are thought to be the precursors for all animals. They are highly related to sponges (Porifera), which are the simplest multicellular animals.
In order to understand the transition to multicellularity during the Precambrian, it is important to look at the requirements for multicellularity—both biological and environmental.
and 29 Related for: Precambrian body plans information
Ediacara Hills in Southern Australia date back to the late Precambrian. These fossils are body impressions of organisms shaped like disks, fronds and some...
current range of bodyplans is far from exhaustive of the possible patterns for life: the Precambrian Ediacaran biota includes bodyplans that differ from...
the known Cambrian lagerstätten are rare and difficult to date, while Precambrian lagerstätten have yet to be studied in detail. The sparseness of the...
highly proliferative clade whose members have a bilaterally symmetric bodyplan. The vast majority belong to two large superphyla: the protostomes, which...
giant impacts that help to increase its overall size. c. 4,533 Ma – The Precambrian (to c. 539 Ma), now termed a "supereon" but formerly an era, is split...
have been proposed. It lived during the late Ediacaran (final part of Precambrian). The discovery of cholesterol molecules in fossils of Dickinsonia lends...
appendages. The idea of bodyplans originated with vertebrates, which were grouped into one phylum. But the vertebrate bodyplan is only one of many, and...
than 3.5 billion years ago. Stromatolites were much more abundant in Precambrian times. While older, Archean fossil remains are presumed to be colonies...
images of each other) during embryonic development. This means their bodyplans are laid around a longitudinal axis (rostral–caudal axis) with a front...
The Avalon explosion, named from the Precambrian faunal trace fossils discovered on the Avalon Peninsula in Newfoundland, eastern Canada, is a proposed...
of animals which do not show any symmetry (i.e. are asymmetrical), the bodyplans of most multicellular organisms exhibit, and are defined by, some form...
erniettomorph found in a number of Precambrian deposits worldwide. It is a member of the Ediacaran biota. The three-lobed body is generally flat such that only...
KJ (January 1, 2007). "Poriferan paraphyly and its implications for Precambrian palaeobiology" (PDF). Geological Society, London, Special Publications...
biodiversity known as the Cambrian explosion. Most of the currently existing bodyplans of animals first appeared in the fossil record of the Cambrian rather...
tectographs from the Itajaí Basin: A cautionary tale from the Precambrian". Precambrian Research. 403. 107307. Bibcode:2024PreR..40307307B. doi:10.1016/j...
near-orderly Wilson supercontinental cycle of events. The range rose in a Precambrian event called the Aravalli-Delhi Orogen. The Aravalli Range is a northeast–southwest...
animals that were originally classified into the Cnidaria. The basic bodyplan of trilobozoans is often a triradial or radial sphere-shaped form with...
events had to occur in order to form the canyon as it is seen today. The Precambrian gneiss and schist that make up the majority of the steep walls of the...
and a common Neoarchean tectonothermal history for West Greenland". Precambrian Research. 314: 129–144. Bibcode:2018PreR..314..129K. doi:10.1016/j.precamres...
occurred at the start of the Ediacaran period. An orogeny folded the older Precambrian rocks. In the Cambrian time the Tyennan block forming the south west...
North America South America Zealandia. Due to lacking the presence of Precambrian cratonic rocks, Zealandia's status as a geological continent has been...
landmark to one of the most unique lower hoodoos, originated during the Precambrian era, known as the Valley Of Marvels or Dakata's Rock Valley which provide...
synapomorphies, the notochord, which plays a significant role in chordate bodyplan structuring and movements. Chordates are also bilaterally symmetric, have...
convincing fossil record of the placozoa, although the Ediacaran biota (Precambrian, 550 million years ago) organism Dickinsonia appears somewhat similar...
Misra in 2007. It represents a frondose rangeomorph, and its overall bodyplan shows glide reflection symmetry, which is typical of the clade. In the...
ISBN 978-0-691-17025-1. The Trace-Fossil Record of Major Evolutionary Events: Volume 1: Precambrian and Paleozoic. Springer. 17 November 2016. ISBN 978-94-017-9600-2. Gehling...
Glaessner, M. F. (1972). "Precambrian palaeozoology". In Jones, J. B.; McGowran, B. (eds.). Stratigraphic Problems of the Later Precambrian and Early Cambrian...
fossil record. The time before the Phanerozoic, collectively called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons. The time...
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