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Hewan pembangun
karang 550 juta tahun yang lalu, studi menemukan fosil
Animals
built reefs 550 million years ago, fossil study finds
Date:
June 26,
2014
Source:
University of Edinburgh
Summary:
It is a remarkable survivor of an ancient aquatic
world -- now a new study sheds light on how one of Earth's oldest reefs was formed.
Researchers have discovered that one of these reefs -- now located on dry land
in Namibia -- was built almost 550 million years ago, by the first animals to
have hard shells.
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It is a remarkable survivor of an ancient aquatic world --
now a new study sheds light on how one of Earth's oldest reefs was formed.
Researchers
have discovered that one of these reefs -- now located on dry land in Namibia
-- was built almost 550 million years ago, by the first animals to have hard
shells.
Scientists
say it was at this point that tiny aquatic creatures developed the ability to
construct hard protective coats and build reefs to shelter and protect them in
an increasingly dangerous world.
They were
the first animals to build structures similar to non-living reefs, which are
created through the natural processes of erosion and sediment deposition.
The study
reveals that the animals attached themselves to fixed surfaces -- and to each
other -- by producing natural cement composed of calcium carbonate, to form
rigid structures.
The
creatures -- known as Cloudina -- built reefs in ancient seas that now
form part of Namibia. Their fossilised remains are the oldest reefs of their
type in the world.
Cloudina were tiny, filter-feeding creatures that lived on the
seabed during the Ediacaran Period, which ended 541 million years ago. Fossil
evidence indicates that animals had soft bodies until the emergence of Cloudina.
Findings
from the study -- led by scientists at the University of Edinburgh -- support
previous research which suggested that environmental pressures caused species
to develop new features and behaviours in order to survive.
Researchers
say animals may have developed the ability to build reefs to protect themselves
against increased threats from predators. Reefs also provided access to
nutrient-rich currents at a time when there was growing competition for food
and living space.
Scientists
say the development of hard biological structures -- through a process called
biomineralisation -- sparked a dramatic increase in the biodiversity of marine
ecosystems.
The study,
published in the journal Science, was carried out in collaboration with
University College London and the Geological Survey of Namibia. The work was
supported by the Natural Environment Research Council, the University of
Edinburgh and the Laidlaw Trust.
Professor
Rachel Wood, Professor of Carbonate GeoScience at the University of Edinburgh,
who led the study, said: "Modern reefs are major centres of biodiversity
with sophisticated ecosystems. Animals like corals build reefs to defend
against predators and competitors. We have found that animals were building
reefs even before the evolution of complex animal life, suggesting that there
must have been selective pressures in the Precambrian Period that we have yet
to understand."
Story
Source:
The above
story is based on materials provided by University of Edinburgh. Note: Materials may be edited
for content and length.
Journal
Reference:
- A. M. Penny, R. Wood, A. Curtis, F. Bowyer, R. Tostevin, K.- H. Hoffman. Ediacaran metazoan reefs from the Nama Group, Namibia. Science, 2014; 344 (6191): 1504 DOI: 10.1126/science.1253393
