Museum Altiocculus harrisi Trilobites Association
harrisi (formerly Alokistocare harrisi)
Order Ptychopariida, Family Alokistocaridae
Time: Middle Cambrian
mm = 1 inch): The Altiocculus trilobite is 1” in length. Bolaspidellas
range from 1/8 to 3/16”. The plate size is 4 x 2 ¾”.
Wheeler Shale, House Range, Utah
Altiocculus harrisi is perhaps the most sought after species
from the Wheeler Shale. The most distinctive feature is the large
number of thoratic segments. They are most often found in association
with the common Elrathia kingi. This one comes from a mudstone
quarry near the world famous U-Dig It Quarry pay site. Percentage
wise, Altiocculus harrisi, though found with Elrathias are extremely
elusive. A specimen of this size and preservation is cause for
celebration indeed. Note the pustules covering the complete carapace.
This is a congenial association plate with two petite Bolaspidellas
overlapping, and looking peacefully at rest on the lower left side
of the large Altiocculus. Another tiny Bolaspidella is located
on the upper right hand side of the plate. The black trilobites
are beautifully framed against the light gray mudstone matrix.
The Altiocculus is in excellent condition, excepting a slight disarticulation
of the bottom seven segments from the thorax. The miniscule pygidium
is also missing. These slight imperfections take little away from
the pleasing aesthetics of this delightful plate. The slight discoloration
surrounding the Altiocsulus is the result of the specimen having
been reinforced and re-seated. The trilobites themselves have had
absolutely no reconstruction or enhancement.
fossil pictures to enlarge