Anomalocaris, meaning "odd shrimp" were
large creatures indeed, probably the largest animals in the Burgess Shale
or the Cambrian Era about 60 cm long. Anomalocaris had a long, oval-shaped
head, large eyes, feeding appendages at the front that look like combs,
and a circular mouth underneath. Behind the head a "trunk" extended,
which took up most of the length of the Anomalocaris, and had lobes underneath
it in pairs which enabled it to swim. Since the Anomalocaris has no legs
or walking appendages, it probably swam all the time, using these lobes.
Starting behind the mouth underneath the head, there were three pairs of
lobes, triangular in shape. Next, there were 11 pairs of larger lobes,
tapering to a point at the end of the animal. All of these lobes were overlapped,
the lobe on top being farther back along the trunk. These lobes would move
up and down in sequence, much like a manta ray swimming. The mouth of Anomalocaris
species was located on the front end of the head, underneath. It was round
and cylindrical, with many tiny teeth facing inward. Food was brought to
the mouth via the feeding appendages, which would capture food and curl
up, bringing the food to the mouth.
When Anomalocaris was first discovered in 1886
at the Ogygopsis trilobite beds, there was some uncertainty as to what
the animal looked like. A feeding appendage was thought to be the tail
of an organism whose head had not yet been found. Tuzoia was originally
thought to be the head, and actual parts of the Anomalocaris were misidentified
as separate organisms, Peytoia and Laggania. Derek Briggs and Whittington
came up with the most probable assemblage of Anomalocaris in 1985.
© Romeo A. Esparrago, Jr.