They are about 15cm in length 1), 3), 4), and have two dermal bone sheilds which provide support for the body as well as protection 4).
There are a gap between two shields, where eyes and external gills open 2), 4).
Since Arandaspis had no jaw, it might have swum with opened mouth and might have filtrated organic matters or smaller organisms 4). They may have lived behind scattered pebbles.
The posterior half of the body is missing from the fossil, so the structure of the fins is unknown 1).
It seems that Arandaspis was not a good swimmer, propelled itself with undulating tail (and head) movement 4).
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