HIr - Desert Magazine of the Southwest

Calevanto Marble from this long-unoperated quarry in the Marble Mountains near
the trilobite collecting area was used in the United States Mint and the Custom
House in San Francisco.
Much more patience and effort are
involved in collecting these fragile fossils
than in picking up pretty rocks.
A shovel and pick or mattock, and a
thin flat blade—such as a putty knife—
prove useful in mining and spitting
chunks of the shale.
We opened dozens of barren layers
for every fossilization worth keeping
but found no entire adult trilobite.
Most of their bones were the head
shields with their spines. A thorax
with its appendages proved a prize
strike and we also uncovered the little
dots which are said to be trilobite eggs,
and the little segmented moults of the
small fry, and various other fossil material.
In most trilobite deposits only
the dorsal shield—the thick upper portion
of the external skeleton—normally
survives and it often splits between
the head shield and the more fragile
thorax. The pieces of shale carrying
the fossils had to be wrapped carefully
in tissues because they were always
soft and sometimes still moist.
Despite its problems and disappointments,
trilobite hunting is a thrill to
me. Even one of these incredibly ancient
little creatures sufficiently preserved
to be identified is worth a morning's
work. The uncertainty of returns
guarantees the field will never be
stripped by quantity collectors. And
since there are many exposures of this
shale in the southeastern Marbles, even
should the marble quarries ever be put
in operation again, fossil hunters can
just go out and locate another ledge.
Lucile and I, on another trip, followed
the pole line road around the tip of
the mountain and found an untouched
ledge with trilobite remains with only
a few minutes prospecting in a likely
canyon.
I do not know if Paddy himself was
among our finds—or if any of his special
variety were. We do have head
shields which look identical with the
holotype of P. mohavensis. But not
being a professor of trilobites who has
spent a lifetime studying variations in
glabella, intergenal spines and the rest,
I can only say they look like Paddy.
Our activities in the shale seemed
to fascinate the local wild life. One
little brownish bird stalked around us
then perched on a rock right beside
Lucile—who speculated it might be a
pipit—and chirped at her inquisitively.
Lizards—particularly plump countryboy
chuckawallas — gathered on surrounding
rocks and gawked. As the
temperature rose they vanished. Toward
noon, with the heat waves rolling
up around us, we decided we'd had
enough, too.
Lucile headed back down to the car
to break out lunch. Bill and I decided
we wanted a closer look and possibly
some photographs of the topsy-turvy
geology before we left. We scrambled
up the steep and shifty talus toward a
break in one of the ledges and there
we came upon one of our chuckawalla
observers, sprawled on a rock point
just outside a miniature cavern.
14 DESERT MAGAZINE