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Ancient Iowans used
many kinds of animal bones as raw material for tools. Along with
artifacts of stone, shell, and wood, bone implements were an important
part of many tool kits. As a raw material, bone is tough and slightly
brittle. With only slight modifications, the scapulae (shoulder
blades) of bison and elk could be made into hoes, and the ulnae
(foreleg bones) of deer could be worked into awls. Other types of
tools such as fishhooks required considerable labor to reach their
desired form.
Modified bison
scapula
Manufacturing Techniques
Softer than most stone and harder
than wood, the hardness and resilience of bone made it particularly
useful. Fresh bone can be split, broken, and splintered. Relatively
fresh bone can be modified in various ways, depending on the form
and size of the bone and the type of tool desired.
Bone Breaking
The simplest means of modifying
bone is by breaking the bone on an anvil with a large hammerstone.
This technique was commonly employed to extract nutritious marrow
from the bone cavity. Long bones of large animals can be cracked
and broken into sharp splinters suitable for immediate use as picks
or scrapers or for further modification into awls and other tools.
This technique of breaking bones is relatively haphazard, but when
coupled with other methods such as grooving or sawing, it can be
used to shape more sophisticated tools.
Breaking
bone using the anvil method
Grooving and Splitting
For some delicate bone tools, it
is first necessary to score the parent bone. Grooves outlining the
intended tool's form are cut through the hard outer bone to the
spongy cancellous tissue using stone tools such as sharp pointed
gravers and chisel-ended burins. The piece can then be broken free
with relative ease and made into an awl or needle. Grooving bone
with a modified flake tool can be slow. Soaking the bone in water
for a few days can speed up the process by temporarily softening
the bone, making cutting and scraping easier. Once the bone is dry,
it will return to its hard, resilient state.
Graver
Using graver to groove bone
Sawing, Drilling, and Grinding
Bone can be sawed into sections
with a serrated bifacial stone knife or flake tool. After the saw
cuts have been made to a sufficient depth, the bone can easily be
broken by hand. Stone drills, either hand held or attached to shafts,
may be used to bore holes through bone for making such tools as
arrow-shaft wrenches. The small eyes of sewing and matting needles
can be made by a sawing or twisting motion with a graver tip.
Polishing, final shaping, and sharpening
were done with a sandstone abrader. Some tools were made almost
totally by grinding.
Bone Tool Types
Since bone is not a universally
well preserved material, we know little about the bone tool technologies
of the cultures prior to the Late Prehistoric period. One of the
earliest musical instruments, however, a bone flute, was recovered
from an Early Archaic site in western Iowa.
Bone flute
After AD 1000, bone tools are well
known. The Mill Creek culture of northwest Iowa (ca. AD 1000_1250)
exhibits a particularly rich assemblage of bone artifacts. Bone
tools are often categorized according to their supposed functions. |
Hoes
Late Prehistoric agricultural groups
of the Midwest and Plains commonly made hoe blades from the scapulae
of bison and elk. The long spine that runs the length of the bone
may be easily broken off after a few deep saw cuts have been made.
Portions of the bone may be broken away to give the blade a more
symmetrical appearance. After the edge has been beveled and ground
sharp, the hoe blade is ready for mounting in a split and notched
wooden handle.
Scapula
hoe
Knives
So-called squash knives also were
made from the scapulae of large mammals. These tools were made by
selecting a portion of the broken shoulder blade and grinding the
thin interior bone edge sharp. Such tools would have served well
in slicing soft plant materials.
Bone squash knife
Scoops
Scoops were made from the bison
horn core and accompanying portion of the frontal bone. These tools
were probably made by breaking off the desired piece of the skull
and grinding the exposed edge sharp. Horn scoops were probably used
as hand-held digging tools.
Horn core scoop
Fleshers
Saw-tooth-edged tools were commonly
made from the long bones of large animals, particularly the metatarsals
(long foot bones) of bison and elk. By breaking the distal end off
at an angle and then sharpening and serrating the exposed edge,
the tool could be used to strip the fatty tissues from the inner
surfaces of fresh hides.
Flesher
Hide Grainers
Tools for scraping and smoothing
the inner surfaces of hides were made by breaking off the heads
of a leg bone of a bison or other large mammal, exposing rough cancellous
interior bone.
Hide grainer
Sickles
Deer jaws were used in an unmodified
state for threshing grasses. The front portion was frequently worked
away and polished smooth.
Deer mandible
sickle
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Arrow-Shaft Wrenches
The ribs of bison and elk as well
as the long bones of deer were sometimes drilled with holes for
use in straightening arrow shafts. When arrow shafts were heated,
these wrenches helped remove warps or irregularities.
Arrow shaft
wrench
Fishhooks
Fishhooks were made by two methods
depending on the bone used. Toe bones of deer were cut and split
lengthwise. The exterior surface of the bone was then removed by
grinding, leaving only the hook-shaped ridge of bone inside. Larger
fishhooks were made by grooving and grinding oval-shaped pieces
of a split rib.
Fishhooks are believed to have been manufactured from bone
"blanks."
Awls
Awls, used as leather punches in
sewing hides, were made from a variety of bones. The ulnae of deer
could be cut, and then ground and polished to form a sharp tip.
Splinters of rib and long bone were also ground into awls. Hollow
bird bones also were sometimes broken and split to form awls.
Awl made from an ulna
Quill Flatteners
So-called quill flatteners are
flat-ended tools made from long splinters of mammal bone. The rounded
and flattened ends of these tools are thought to have been used
in flattening porcupine quills for use as decoration. They may also
have been used as pressure flakers in flintknapping or for smoothing
in pottery making.
Quill flattener
Antler Artifacts
Like bone, antler is tough and
resilient. Unlike bone, however, antler is relatively solid and
varies greatly in form among individual deer. Antlers are grown
by male deer and are shed each winter. Antlers were perhaps most
important to prehistoric groups for use as flintknapping tools.
Soft hammer batons for controlled percussion flaking were made from
the basal portions of antlers by cutting them to length and grinding
off the rough burr at the base. Antler tips, cut to lengths of 3
to 10 inches, were used as pressure flakers. Antler tips were sometimes
cut and drilled to make conical arrowpoints.
Base
of antler used as soft hammer baton
Antler tine
used as pressure flaker
Adapted from a manual prepared
by Toby Morrow.
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