Viegas & Benton, 2014: A CONSERVATION AND PREPARATION OVERVIEW
THE EXISTING COLLECTION
numbering happened only after every effort
had been made to match broken pieces
In order to resolve the mix of crates and
together, and specimens with numbers.
cabinets with boxed, unboxed, cataloged,
uncataloged, and half prepared, unprepared
and prepared pieces of bone and rock,
MICROVERTEBRATE STUDY
everything had to be taken out of the
The approximately four tons of rock consisted
containers, laid out on big tables and sorted
of several dozen blocks, of different sizes, from
(Figure 7a). This sorting had to be done in
cobble size to large boulders, and these were in
several sessions since there was not enough
different conservation stages. Some showed
table space to accommodate the huge amount
various degrees of preparation work that had
of existing material. At the same time, a hugely
been done in the past, anything from chisels
demanding task began, puzzling bone by bone,
and air scribe scratch marks to different
shard by shard to figuring out which one would
degrees of previous acid immersions, or in
fit with the next bone and in what order (Figure
fewer cases presenting no signs of any work
7b). Bones and shards were glued using
besides the quarry extraction and later moves.
ParaloidTM B-72 (B-72) in up to 40% by volume
Since the dinosaur has been known for almost
in acetone, and consolidation was made using a
200 years, but not many studies had
5 to 15% dilution by volume.
considered details of its ecological setting, it
Specimens were then sorted into groups of
was decided to give first priority to investigate
anatomically similar elements, including initially
the sedimentary characters of the rocks and
a categorization as vertebrae, ribs, and long
the associated microvertebrate fauna.
bones. These were then sub-divided further
Blocks that could easily be handled by one
into more specialized categories such as tail
person and that presented diverse matrix and
vertebrae and claws, as readily identifiable
grain compositions were made the priority.
anatomical categories (Figure 8).
These were placed in buckets, ranging in
This collection included several specimens that
volume from five to 25 liters, depending on
had been subject to some preparation work in
their size, and acid digested using a 5% acetic
the past. Dull, dark, coated specimens were
acid
solution
buffered
with
tricalcium
washed with a soft wide brush soaked with
orthophosphate. Visible specimens on these
either ethanol or acetone (if the ethanol rinse
rocks were assessed for their condition and
did not affect this dark coating specimens were
capability of withstanding acid digestion cycles
successfully
cleaned
with
acetone).
The
prior to any acid immersion. If too fragile, they
difference between the cleaned and uncleaned
were removed or cut with the surrounding
specimens was impressive (Figure 9). In other
matrix from the block and mechanically
cases, specimens had been glued together at
prepared. Specimens that could withstand acid
the wrong angle or with the wrong bone; these
preparation were consolidated if necessary and
specimens had to have their bonding material
a thin coating of either MowitalŽ B60 HH (M-
removed by diluting it with acetone or softening
B60) in a 5 to 10% solution in ethanol or B-72
it with a hot-air gun, and gently pulling the
in a 5 to 10% solution in acetone applied to
bonding material with tweezers or a pin vice.
them in order to act as a supplemental acid
After sorting, consolidating, washing and
barrier and prevent any total or partial loss in
gluing, specimens were housed in plastic
case a break occurred; the choice of coating
StyronTM 678E series (Styron) boxes and
agent was determined by numerous factors
padded with PlastazoteŽ foams. Three foam
inherent in the specimens themselves such as
thicknesses and two different densities were
conservation
state,
brittleness,
size
and
used. PlastazoteŽ LD45 (LD45) was used in 5
anatomy of the specimen. While large, robust,
and 4 mm, the density most commonly used
smooth specimens received a coating of B-72,
for storage of museum specimens, while a
smaller, more delicate, ornamented specimens
much softer PlastazoteŽ LD15 (LD15), 3 mm
were generally coated with M-B60.
thick, was used to pad all cabinet drawers and
Acid preparation took over 2 years of daily
box bottoms, providing a non-slip, padding
routines such as solution changes, rinsing,
layer (Figure 10).
sieving, picking, identification and packing, and
New accession numbers were given to
produced thousands of microfossils and the
specimens that had not been cataloged yet or
creation of a new, Triassic, microfossil research
had lost their numbers over the years. None of
collection at the University. The new laboratory
these specimens had been published, and re-
space has great extraction capabilities and all
57 Journal of Paleontological Techniques