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Australia: The Land Where Time Began |
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A
Suspension-Feeding Anomalocaridid from the Early Cambrian Through the history of life on Earth large,
actively swimming suspension feeders have evolved several times, arising
independently in groups such as sharks, rays and stem teleost fish, as
well as in mysticete whales, though such animals have not been
identified from the Early Palaeozoic Era. In this paper the authors1
report the finding of new material from
Tamisiocaris borealis,
and Anomalocarid from the Serius Passet Fauna of North Greenland, Early
Cambrian (series 2), and propose that its frontal appendage has been
specialised for suspension feeding. On
these appendages there are long, slender ventral spines that are equally
spaced and have dense rows of long and dense auxiliary spines. It is
suggested by this that
T. borealis was a
microphagous suspension feeder, the appendages being used for sweep-net
capture of food items down to 0.5 mm, which is in the size range of
mesozooplankton such as copepods. It is suggested by these observations
that the earliest appearance of suspension feeders was in the Cambrian
explosion, part of an adaptive radiation of anomalocarids. The existence
of a complex pelagic ecosystem supported by high primary productivity
and flux of nutrients is indicated by the presence of nektonic feeders
in the Early Cambrian, as well as evidence of a diverse pelagic
community that contained phytoplankton and mesozooplankton. The authors1
suggest that pelagic ecosystems of the Cambrian appear to have more
modern than previously believed. Vinther, Jakob, Martin Stein, Nicholas R.
Longrich, and David A. T. Harper. "A Suspension-Feeding Anomalocarid
from the Early Cambrian." Nature 507, no. 7493 (03/27/print
2014): 496-99.
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |