| Zooarch Home | Todd Classes | Class Outline | Class Projects | Grades | Bison Osteology | Coding Bones | Announcements | Links | Contact Information |
Why is anatomy important? Notes to accompany Zooarcharchaeolgy Lab Sessions
Ryan Hurtado - 2001
In zooarchaeology we use animal bones as indicators of past human behavior, paleoecology, and past environments. These bones have undergone various processes in life, death, burial and recovery which need to be understood in order find out what information they can contribute in understanding past human populations. Taphonomy is the study of these processes examining the transition of objects from the biosphere to the lithosphere to the archaeologist’s laboratory. The archaeologists studying these processes use anatomy to classify, organize, and describe assemblages of bones recovered from the archaeological record.
In the field, skeletal anatomy is important so that the excavator can describe the bone’s position and provenience, the location in three-dimensional space. A description of a bone’s position and provenience require that the excavator know what side of the bone is facing up, and what end of the bone is situated highest. With this information along with the bone’s orientation (compass baring along the long axis), inclination (slope or dip of the long axis), and a provenience point (three-dimensional coordinates in space) the position and location of the bone can be reconstructed.
In the laboratory, bones are cleaned for further more detailed analysis. Often times human and non-human modifications (cut marks, bite marks, etc.) are found, requiring a detailed description of their location on the bone. A wealth of biological information such as the animal’s sex, size, health and age can be obtained through various types of analysis, which require a detailed understanding skeletal anatomy and the names of landmarks that anatomists have defined. One of the key indicators of past human behavior is patterning found among the different skeletal elements. An element is a particular bone within the skeletal system for example our femur, upper leg bone, is an element. In some assemblages, bones associated with particularly meaty areas are predominately found, whereas in other assemblages non-meaty bones are found indicating different human behavioral patterns. Last, the zooachaeologist is always looking for new and better ways to understand past human populations, requiring a working knowledge of skeletal anatomy to sift through the data for correlations, meaningful connections and regularities.
Directional
terms
Directional terms
are used to describe how bones or sections of bones relate to the rest of the skeletal
system. It is important to familiarize your
self with these terms because they make up the basic language used in anatomy. Below the directional terms are given that are
different for quadrupedel animals and humans.
Quadruped |
Description |
Human |
Cranial-Caudal |
The cranial or superior surface or part of a bone is closer
to the head. The caudal or inferior
surface or part of the bone is closer the tail in quadrupeds and to the feet in humans. |
Superior-Inferior |
Dorsal-Ventral |
The dorsal or posterior terms refer to the uppermost
portions of vertebrate in quadrupeds and the portions closest to the surface of the back
in humans. The ventral or anterior portions of the vertebrate that are
closest to the abdomen. |
Posterior-Anterior |
The rest of the terms
are the same for humans and quadrupeds and are given below.
Terms |
Description |
Cranial-Postcranial |
The cranial portion of the skeleton is the head
consisting of the cranium mandibles, and the hyoid. The
postcranial portion consists of everything
else, the vertebrate, pelvis, ribs, and limb bones.
|
Axial-Appendicular |
The axial skeleton describes the trunk of the body
including the vertebrate, ribs, and pelvis. The
appendicular skeleton describes the limb bones
or appendages. |
Medial-Lateral |
Medial portions of
bones are closest to the midline of symmetry or sagittal plane. Lateral
portions of bones are that are farthest from the midline of symmetry or sagittal plane. |
Proximal-Distal |
The proximal portion of a limb bone is closest to the
trunk or axial skeleton when the animal is in normal anatomical position. The distal
portion of a limb bone is farthest from the trunk of axial skeleton. |
Right-Left |
|
The
four classes of bones
1. Long bones—the primary
components of limbs, support weight, and work with muscles in a lever system for movement.
2. Short bones—the
metacarpals and metatarsals in feet and hands (in humans), the phalanges or finger bones,
characterized by compactness, elasticity, and limited motion.
3. Flat bones—cranial
bones, os coxae (portion of pelvis), and scapulae; these provide protection (cranium) a
large area for muscle attachment (os coxae and scapulae).
4. Irregular bones—vertebra,
carpal and tarsal (hand and feet bones), and many of the cranial bones, these are complex
and have particular forms for the functions they perform.
The next important
step in learning skeletal anatomy is learning the elements of the skeletal system. For the most part you have the same contingency of
skeletal elements as a quadruped so it is effective to use yourself as a model for
learning. An element code is given with each
element. This should be memorized along with
the element because this is the notation that we will be using to help organize large
quantities of data for analysis. The element
code is used with other codes to describe the most relevant pieces of information about a
bone. In the last exercise you will learn
about this coding system.
Axial
Skeleton – Skull
There are three
main parts or elements of your skull, the cranium (CRN), the mandible
(MR) or jaw bone and the hyoid (HY), which serves as an attachment
for tissue related to vocal and repertory functions.
CRN cranium
MR mandible
HY hyoid
Axial Skeleton
– Spine
Your spine is made
up of five groups of vertebra. First, most
superior in the area of your neck you have 7 cervical vertebrae (CE). Bison along with most other quadrupeds also have
seven cervicals. Moving inferior the
next group which make up your upper back are called thoracic vertebrae (TH). The number of thoracics varies across
species and sometimes within a species. Humans
typically have 12 thoracics while bison usually have fourteen. Your lower back region is typically made up of 5 lumbar
vertebrae (LM). The axial portion
of your pelvis is called the sacrum (SAC) and is usually made up of five
fused sacral vertebrae. Typically bison have
the same number of lumbar and sacral vertebrae as humans, five. The last, most inferior group is made up of caudal
vertebrae (CA) that has a few (3-5) vestiges from our evolutionary past. There is a great deal of variation in the number
of caudal vertebrae in quadrupeds, bison typically have somewhere around twenty.
CA caudal vertebrae
Axial Skeleton
– Ribs and Sternal Elements
The rest of the
axial elements are in the trunk or thoracic region. Ribs
(RB) maintain the form of the trunk. There
are usually as many ribs as there are thoracic vertebrae the ribs are joined anteriorly by
sternal bodies (SN). The most
superior or cranial sternal element is called the xiphoid (ZY). The most inferior or caudal sternal element is
called the manubrium (MN). The xiphoid and the manubrium are separated by sternal
bodies (SN) providing anterior attachment for the ribs.
There is also a cartilage that forms between your ribs in your anterior thoracic
region called costal cartilage (CS). Humans
also have a clavicle that is not present in most quadrupeds which runs from the scapula to
the sternum.
RB rib
SN sternal bodies
ZY xiphoid
MN manubrium
CS costal cartilage
Appendicular
Skeleton – Arm or Front Limb
The most proximal
element in your arm is your scapula (SC) sometimes called the shoulder bone. Moving distally, your humerus (HM) is
located in the upper arm. Your fore arm is
made up of your radius (RD) and ulna (UL) with your radius on the thumb side
and ulna on your pinky side. Your wrist is made up of carpals (CP) and hand metacarpal
(MC). Your finger bones are called phalanges. The
most proximal one is called the first phalanx (PHF) followed by the second phalanx
(PHS), with the third phalanx (PHT) most distal. Your thumb contains only the first and second
phalanx. Your hand contains very small bones
called sesamoids that attach to tendons. A
bison has four proximal sesamoids (SEP) and two distal sesamoids (SED). Examine the differences between bison and human
limb anatomy.
UL ulna
PHS second phalanx
PHT third phalanx
SEP proximal
sesamoids
SED distal
sesamoids
Appendicular
Skeleton – Leg or Hind Limb
The most proximal
element in the leg is the os coxae or innominate (IM) commonly called the hipbone. Our left and right innominate along with the
sacrum makes up the pelvis. Our upper leg
bone in the area of our thigh is called the femur (FM). There is a bone in your knee called the patella
(PT) commonly called the kneecap. The patella can also be classified as a sesamoid. The next two bones in your lower leg are your tibia
(TA) commonly called your shin bone and your fibula, which is not present in
most quadrupeds. Distal to the tibia and
fibula are the tarsals (TR). Your heel
bone is an example of a tarsal its called the calcaneus.
Next follows the metatarsals (MT) in between your tarsals and your toes. Your toes are made up of first, second and third
phalanxes just like your fingers. In bison
front and hind limb toes and sesamoids are similar and are very difficult tell apart.
PT patella
MT metatarsals
Reconnoitering
Bison Vertebrae
The cervical vertebrae make up the
section we call the neck. The muscles that
attach to the cervices are primarily responsible for movement of the head. Both humans and bison have 7 cervicals. The first cervical is called the atlas (AT)
named after the Greek mythological titan who supported the earth on his shoulders,
analogous to the atlas’s job of articulating or “holding” the head. The atlas is unique in that it is the only
vertebrae that dose not have a body. The
atlas articulates with the occipital condyle of the cranium that produces the up and down
“yes” motion of the head. The
landmarks important to know for identification and orientation include alar foramen,
cranial articular cavity, caudal articular surface, dorsal tubercle, vertebral foramen and
the wing. Be sure to identify these on
a comparative skeleton.
AT atlas
alar foramen
cranial articular cavity
caudal articular surface
dorsal tubercle
wing
vertebral foramen
The second cervical vertebrae is
called the axis (AX) and is easily recognizable by its large wide spinous
process and the dens the process which sticks into and articulates with the
atlas. This articulation between the axis and
the atlas allows the side to side “no” movement of the head. Other landmarks to recognize include the transverse
foramen, vertebral foramen where the spinal cord runs through and transverse process and the centrum or
body.
AX axis
spinous process
dens
transverse foramen
transverse process
centrum
Cervicals – CE3, CE4, CE5, CE6, CE7
The next couple of cervicals CE3,
CE4, and CE5 are somewhat difficult to differentiate from each other. The sixth
cervical (CE6) can be distinguished by its large and thick transverse process. The seventh
cervical (CE7) has a long spinous process and is easily confused with the thoracic
vertebrae. It is recognized by its wide
transverse processes similar to the other cervicals.
Also it has a cervical like cranial articular surface of the centrum and thoracic
like caudal articular surface of the centrum which has costal pits. Costal pits are the surfaces on the vertebrae
where the ribs articulate. The landmarks you
should know include the spinous process, transverse foramen, centrum, vertebral
foramen, transverse process and their articular surfaces, and costal
pits which are only found on the CE7. It
is important to note that cervicals are the only vertebrae with transverse foramen,
which is a useful landmark for identification. When
looking at the centrum of any vertebrae the convex articular surface is toward cranial and
the concave surface is toward caudal.
CE (CE3
-- CE5)
CE6
CE7
spinous process
transverse foramen
transverse process
centrum
costal pits (only on CE7)
vertebral foramen
Thoracics make up the area of the
main back. Bison usually have 14 thoracics TH1
– TH14, which are easily recognized by their massive dorsal spines, which provide
the muscle attachment for supporting the weight of the massive head. The first thoracic is most cranial and the
fourteenth is most caudal. They also have
widely spaced articular processes on the cranial side with slightly skinnier articular
processes on the caudal side. The other main
trademark of the thoracic vertebrae is the costal pits on the articular surfaces of the
centrum. This gives it the outline of a
Mickey Mouse shape, with the main articular surface of the centrum forming the head and
the ears formed by the costal pits. The fourteenth
thoracic TH14 can usually be distinguished from the others because it will have costal
pits on the cranial surface, but none on the caudal surface. Also the articular processes on the caudal side
are wider and exhibit the interlocking hook shape of the lumbar vertebrae. The important landmarks to know on the thoracics
include costal pits, centrum, spinous process, transverse processes, vertebral foramen,
and articular processes.
TH (TH1
– TH13)
TH14
costal pits
centrum
spinous process
transverse processes
vertebral foramen
articular processes
Lumbars LM1 – LM5
Bison usually have 5 lumbar vertebrae
LM1— LM5 with the first most cranial and the fifth most caudal. They have very distinctive hook like interlocking
articular processes. These interlocking
articular processes hold the lumbars together making them some of the last elements to
disarticulate. Lumbars are also easily
recognized by there large transverse processes. The
centrum of the lumbar is wider then the others and usually has somewhat of a hart shape. The important landmarks to know include the articular
processes, spinous processes, centrum, transverse process and vertebral foramen.
LM (LM1-LM5)
articular processes
spinous processes
centrum
transverse process
vertebral foramen
Sacrum SAC and Sacral Elements SA1 – SA5
In a mature animal the sacral
elements SA1 – SA5 are fused forming a complete sacrum SAC. The sacrum has an auricular process that
where the vertebral column meets the os coxae of the appendicular skeleton. There is no movement at the auricular surface. The other landmarks that are important include the
medial crest, lateral crest, ala or wing, sacral foramen and the vertebral
foramen.
SAC
SA (SA1-SA5)
auricular process
auricular surface
medial crest
lateral crest
ala
sacral foramen
vertebral foramen
Caudals CA
A bison usually has anywhere from 15
to 18 caudal vertebrae forming the tail. Often
times these vertebrae are misidentified as some other species because of their small size. The most distal caudals look very odd and are even
mistaken for phalanges.
CA (CA1-CA18)
Bison have 14 Ribs, RB1 –
RB14 on each side, left and right. Ribs
have two articular areas on the proximal end, the head articulating with the
vertebrae centrum in the costal pit and the tubercle articulating with the
transverse process. The head always points in
the cranial direction. In between the head
and the tubercle lies the neck. The
neck has around a 90-degree angle at the first rib RB1 that slowly tapers out in the
caudal direction. The main body of the rib is
called the blade. On the caudal edge
of the blade there is an indentation called the caudal groove.
RB (RB1-RB14)
head
tubercle
neck
blade
caudal groove
Sternal
Bodies SN Costal Cartilage CS
The area where the ribs meet is
called the sternum and is made up of sternal bodies SN.
The most cranial sternal body is the xiphoid ZY and is recognizable by
its sharper edges then the others. The most
caudal sternal body is the manubrium MN. Costal
cartilage CS is located at the distal end of the ribs in between the ribs. The sternal bodies and costal cartilage are
typically very spongy.
SN
ZY
MN
CS
Appendicular Axioms of bison
bison bison
Scapula SC
The scapula SC is free
floating and has no direct articulation with the axial skeleton. The scapula has a side with a spine, and a
side without. The side with the spine is the
lateral side with the supraspinous fossa on the cranial side of the spine and the infraspinous
fossa on the caudal side of the spine. The
infraspinous fossa has more surface area then the supraspinous fossa. The side without the spine is the medial side
that has the fossa subscapularis. The
distal end of the spine (toward the socket joint) is called the acromion. At the most distal end of the scapula is the
socket joint that articulates the humerus called the glenoid cavity. Directly above the glenoid cavity on the cranial
side lies the superglenoid tuber. The
area between the superglenoid tuber and the acromion, all the way around the bone is
called the neck. At the proximal end on the
cranial edge lies the cranial angle, where the caudal angle lies on the
caudal edge.
SC
Spine
supraspinous fossa
infraspinous fossa
fossa subscapularis
acromion
glenoid cavity
superglenoid tuber
cranial angle
caudal angle
Humerus HM
The next bone down distally from the
scapula is the humerus. The end with a smooth
ball like articular end called the head is the proximal end. The head is located on the medial side making it a
good landmark to determine orientation and side. On
the lateral side of the proximal end lies the major tubeosity. Moving down the bone the next major landmark
on the lateral side is the deltoid tuberosity.
On nearly the opposite side of the deltoid tuberosity is a bumpy area called the teres
major tubercle. The whole middle
are of the humerus between the proximal and distal ends is called the shaft. The medial side of the shaft is almost flat while
the lateral side is concave. On the distal
end the wider side is medial, with the articular surface of this side called the trochlea. On the lateral side the articular surface is
called the capitulum. On the cranial
side there is a slight indentation above the articular surface called the radial fossa. On the caudal side there is an indentation that is
much deeper called the olecranon fossa. The
area directly above the articular surface on the medial side is called the medial
epicondyle while the lateral epicondyle lies directly above the lateral
articular surface.
HM humerus
head
major tuberosity
deltoid tuberosity
teres major tubercle
shaft
trochlea
capitulum
radial fossa
olecranon fossa
medial epicondyle
lateral epicondyle
Radius – Ulna RDU, RD, UL
The next bones distal from the
humerus are the radius RD and the ulna UL.
Often times the bones are found still fused together, in which case we code the
pair RDU. In anatomical position the
radius is on the cranial side and the ulna caudal. The
ulna has a large muscle attachment on the proximal end called the olecranon tuberosity
projecting off the olecranon of the ulna. Part
of the olecranon glides in and out of the olecranon fossa of the humerus during movement. At the tip of the olecranon on the cranial side
lies the anconeal process. The portion
of the ulna that articulates with the trochlea of the humerus is called the trochlear
notch that lies directly distal to the anconeal process. At the distal end of the ulna lies the styloid
process of the ulna that usually attaches to the radius on the posteriolateral side. In between the proximal and distal ends of the
ulna lies the shaft of the ulna. On the
proximal end of the radius the wider side is medial which has the capitular fossa articulating
with the capitulum of the humerus. On the cranial side near the proximal end lies a muscle
attachment site called the radial tuberosity.
In between the proximal and distal ends of the radius lies the shaft of the
radius. In between the radius and the
ulna near the proximal end lies the interosseous space.
RD radius
UL ulna
RDU radius and ulna fused
olecranon tuberosity
olecranon
anconeal process
trochlear notch
styloid process
capitular fossa
radial tuberosity
shaft of the radius
interosseous space
Carpals CPR, CPI, CPU, CPA, CPS, CPF
Distal to the radius and ulna lies a
set of 6 short bones called the carpals. There
is a proximal row containing 4 carpals medial to lateral CPR, CPI, CPU, and CPA;
and a distal row containing 2 carpals medial to lateral CPS, and CPF. The proximal most medial carpal is called the radial
carpal CPR, articulating with the radius proximally. If you orientate this carpal
until you find a saddle like shape on one of the articular end this is the proximal end
with the high point of the saddle on the caudal side.
Knowing that the no articular side is medial the carpal can be orientated to
determine which side it’s from. Next the
intermediate carpal CPI articulates with the lateral side of the radial carpal. The most prominent feature on this carpal is the
non-articular surface that has a pentagon shape, this is the cranial surface. The two shortest edges of the pentagon that come
to a point are the distal boarder. If you
hold this carpal looking at the pentagon with the distal border pointing down then rotate
it 90 degrees looking at the proximal surface there is a projection that indicates what
side the carpal is from. The ulnar carpal
CPU articulates with the lateral side of the intermediate carpal. Find the non-articular surface that is on the
cranial and lateral sides. The articular
surface that looks similar to a slide is the proximal end.
Knowing that the slide is proximal and the non-articular surface is cranial and
lateral the carpal can be orientated to determine side.
The accessory carpal CPA articulates with the caudal side of the ulnar
carpal. It is often times difficult to
determine side of this carpal. In the distal
row on the medial side lies the fused 2nd and 3rd carpal CPS. The non-articular surface of this carpal is on
the cranial and medial sides. The cranial
side has a prominent point on the proximal border where the radial carpal and the
intermediate carpal meet. Side can be
determined by orientating the carpal into anatomical position. The fourth carpal CPF articulates with the lateral side of the fused 2nd
and 3rd carpal. The non-articular
surface of this carpal is on the cranial and lateral sides.
The cranial side had a point on the proximal border where the intermediate carpal
and the ulnar carpal meet. Side can be
determined by orientating the carpal into anatomical position.
CPR radial
carpal
CPI
intermediate carpal
CPU ulnar carpal
CPA accessory carpal
CPS fused 2nd and 3rd
carpal
CPF fourth carpal
Metapodial
MP MC MT
Metacarpals MC
and metatarsals MT look very similar and only a fragment is found and it cannot be
determined if is a metacarpal or a metatarsal it is classified as a metapodial MP. The end of the metapodial with smooth articular
ends is proximal and the end with rounder articular ends id distal. The cranial side is more rounded on the shaft and
the caudal end is more flat. Examining the
proximal and distal ends the medial side is noticeably thicker then the lateral side. The main difference between metacarpals and
metatarsals is in the shaft cross section. Metacarpals
will be more C-shaped while metatarsals will be squarer shaped.
metapodial
MP
metacarpal MC
metatarsal MT
Phalanges PH, PHF, PHS, PHT
Bison
have two toes on each foot and three phalanges in each toe.
The code PH
is used when a fragment is known to be a phalange but which specific one it is not known. The first phalanx PHF
and the second phalanx PHS
look somewhat similar except the first phalanx is longer.
The concave rounded articular end is the proximal end and the convex articular end
is distal for both PHF and PHS. The third phalanx PHT is
sort of triangular shaped and looks king of like a bird beak or an elf boot with the tip
the beak or the toes of the boot being distal and the articular end proximal. The cranial side of the first and second phalanges
runs with the direction of articulation and is somewhat rounder and smoother while the
caudal side is more bumpy and flatter. It is
difficult to determine the medial and lateral side of phalanges because they are so
similar, instead axial and
abaxial
used. Axial denotes the inner surface and
abaxial is the outer surface. On the first
and second phalanges the axial side is usually straighter and the abaxial side is usually
more concave. In the third phalanx the
abaxial side is the surface with the most surface area.
PH unknown
phalanx
phalanx PHF
second phalanx PHS
third phalanx PHT
axial
abaxial
Sesamoids SEP, SED
The two types of sesamoids in the
foot are the proximal sesamoids SEP and the distal sesamoids SED. There are four proximal sesamoids per foot,
and two distal sesamoids per foot. The
proximal sesamoids are usually more rounded and the distal sesamoid are usually more cubic
shaped and flatter. It is difficult to
determine the orientation of sesamoids.
proximal sesamoids SEP
distal sesamoids SED
Os coxae IM
The
os
coxae IM (innominate)
is made up of three main components, the ilium,
ischium
and the pubis
which all meet at the acetabulum
which is the socket joint where the femur articulates with.
The ileum is the cranial portion of the innominate, it has the auricular surface
where the sacrum attaches. Near the auricular
surface on the dorsal side lies the sacral tuberosity.
On the most cranial-lateral portion of the ileum lies the coxal tuberosity. The most caudal portion of the innominate is the
ischium. On the most caudal-lateral portion
lies the ischiatic tuber. Medial to the acetabulum lays the pubis portion of
the innominate. The pubis and the ischium
together form a large hole called the obturator foramen. The pubis and ischium fuse to the other half of
the innominate at the pubic symphysis. The
narrowest portion between the left and right obturator foramens is where the pubis and the
ischium fuse together.
os coxae IM
ilium
ischium
pubis
acetabulum
coxal tuberosity
ischiatic tuber
obturator foramen
pubic symphysis
Femur FM
The femur FM articulates with
the acetabulum of the os coxae at a ball like feature on the proximal-medial end called
the head. There is a small divot in
the head called the fovea capitus. The
other main feature on the proximal-lateral end is the major trochanter. Directly below the head of the femur lies a
narrow area called the neck of the femur. The
next landmark moving down is the trochanteric fossa an indentation on the caudal
side of the bone near the proximal end. Below
the trochanteric fossa on the caudal-medial side of the bone lies a muscle attachment
called the minor trochanter. On the
caudal-lateral side of the bone near the distal end lies an indentation called the supercondyloid
fossa. The main articular surface on the
distal end is called the trochlea that is on the cranial and distal side. Above the trochlea on the medial side lies the medial
condyle with the lateral condyle on the lateral side.
FM femur
head
fovea capitus
major Trochanter
neck
trochanteric fossa
minor Trochanter
supercondyloid fossa
trochlea
medial condyle
lateral condyle
Tibia TA
The tibia TA articulates with
the femur at the knee. The proximal side of
the tibia is much wider then the distal end of the tibia.
On the proximal end there is a protrusion that sticks out between the two articular
surfaces called the intercondyloid eminence. The
medial side is thicker the lateral side. The
medial articular surface is called the medial condyle while the lateral articular
surface is called the lateral condyle. On
the cranial-lateral side of the proximal end there is an indentation called the extensor
sulcus. On the cranial side of the
proximal end there is a tendon attachment called the tibial tuberosity. Directly below this on the cranial side there is a
ridge that runs down half the shaft called the tibial crest. On the caudal side approximately one third of
the way down from the proximal end lies the posterolateral nutrient foramen. Also on the caudal side there are some distinctive
muscular lines that are useful for identifying tibia fragments. On the distal end of the bone on the medial side
there is a protrusion called the medial malleolus.
On the lateral side of the distal end of the bone there is an indentation
called the groove for lateral digital extensor tendon.
TA tibia
intercondyloid eminence
medial condyle
lateral condyle
extensor sulcus
tibial tuberosity
tibial crest
posterolateral nutrient foramen
muscular lines
medial malleolus
groove for lateral digital
extensor tendon
Tarsals CL, AS, TRC, TRS, LTM
Distal to the tibia are the short
bones called the tarsals. The largest of this
group is called the calcaneus CL. The
calcaneus has a large muscle attachment on its proximal end called the calcaneal
tuberosity. Below the calcaneal
tuberosity there is a smooth and a bumpy side of the bone, the smooth side is cranial and
the bumpy side caudal. When looking at the
bone from the cranial side with the proximal side up there is a part that sticks out right
above the articular surfaces, this is called the sustentaculum, which is on the
same side as side of animal the bone is from. On
the cranial side on the proximal tip of the articular surface a small protrusion sticks
out called the corocoid process. The
next tarsal called the talus AS looks like a duck from the lateral view. The nose of the duck is toward proximal and the
hind end is toward distal, the head toward cranial and the belly toward caudal. The proximal articular surface articulates with
the tibia. The talus articulates on the
distal end with the fused central and 4th tarsal TRC. The fused central and 4th tarsal has a
protrusion on the proximal end on the caudal–medial side. When looking from the cranial side with the
proximal side up the protrusion is on the side that the side of the animal the bone is on. On the distal-medial side of the TRS there is a
slot where the fused second and 3rd tarsal TRS fits. From the cranial view of this tarsal looks like a squished narrowed version of the fused
second and third carpal. This tarsal can be
sided by remembering that the non-articular surfaces are medial and cranial. The lateral malleolus LTM strictly
speaking is not a tarsal but is found with the other tarsals on the lateral side of the
talus. The lateral malleolus looks like a
crown with the point of the crown on the proximal side.
There is a sloping articular surface on the medial side that always slopes down
toward the cranial side.
TR Tarsals
CL calcaneus
calcaneal tuberosity
sustentaculum
corocoid process
AS talus
TRC fused central and 4th
tarsal
TRC fused second and 3rd
tarsal
LTM lateral malleolus
A Cranial Compendium of bison
bison bison
Cranium CRN
The cranium is made up of an
assortment of flat bones protect the brain, house the visual, auditory, and olfactory
sensory systems, and process food. Beginning
with a dorsal view the forehead, area between the eyes is called frontal FN. The area that houses the eyes is called the orbit. Cranial or more toward the nose of the frontal are
the nasals NSL. The most cranial
aspect of the cranium is the incisive INV. Cranial
to the orbit there is a small area of bone called the lacrimal LC. The horn core on the caudal end is called corneal
process HC. Switching to a ventral view
on the most caudal part of the cranium lies the foramen magnum the large hole where
the spinal cord runs through. On the sides of
the foramen magnum lie the articular surfaces called the occipital condyles OCC. The bone medial to the corneal process or horn
core is called the temporal TMP. In
between the teeth lie the palatine process or the roof to the mouth. From a nuchal (caudal) view the occipital OCC can
clearly be seen along with two protrusions off the occipital on either side of occipital
condyle called the jugular process. From
a lateral view the zygomatic ZGO can be seen directly below the orbit turning into
the zygomatic arch in the caudal direction. The
zygomatic arch runs into the temporal bone leading to the external acoustic meatus where
sounds enter and are transformed into sensory signals in the petrous of the skull. The petrous is a hard and durable and is often one
of the last parts of the cranium that deteriorates. The upper teeth lie in the maxilla
MX portion of the cranium. Right above
the row of teeth on the maxilla lies the facial tuber.
CRN cranium
frontal FN
orbit
nasal NSL
incisive INV
lacrimal LC
corneal process HC
foramen magnum
occipital
condyles OCC
temporal TMP
palatine process
occipital OCC
jugular process
zygomatic ZGO
external acoustic meatus
petrous
maxilla MX
facial tuber
Mandible MR
The mandible MR holds the
lower row of teeth and makes up the jaw. Instead
of medial and lateral the term buccal is used referring to the side on the outside
of the mouth and the term lingual is used referring to the side on the inside of
the mouth. The row of teeth is simply
referred to as the tooth row. On the
caudal ventral side the section that makes a sharp corner is called the angle. Dorsal to the angle the area is called the ascending
ramus. On the lingual side of the
ascending ramus lies a hole where the lingual nerve enters the mandible called the mandibular
foramen. On the most dorsal part of the
ascending ramus lies a smooth articular surface that articulates with the cranium called
the condylar process. The condylar
process is separated from a protruding muscle attachment called the coroniod process
by a gap called the mandibular notch. On
the most cranial aspect of the mandible lie the incisors or the empty hole where
the incisors had been. On the lingual side of
the cranial end is a bumpy surface called the
symphyseal surface the left and right sides fuse together. On the buccal side of the cranial end is another
hole where a nerve passes through called the mental foramen.
MR mandible
buccal
lingual
tooth row
angle
ascending ramus
mandibular foramen
condylar process
coroniod process
mandibular notch
incisors
symphyseal surface
mental foramen
| Zooarch Home | Todd Classes | Class Outline | Class Projects | Grades | Bison Osteology | Coding Bones | Announcements | Links | Contact Information |