Module 4: Bones-Appendicular-Forelimb

Question 1

Clavicle

Answer 1

Present in some mammals, may be vestigial/absent
May be useful for species ID
Fish have, turtles have in plastron, birds-wishbone

Question 2

Ribs

Answer 2

12 per side-24 total, sometimes more
First 7 articulate w sternum (true ribs)
8,9,10 articulate via common cartilage (false ribs)
11- do not articulate (floating ribs)
Vary according to species
Head articulates w body of 2 vertebrae (double articular facet on head)
Caudal ribs have single articular facet
Neck-between head and tubercle; articulates with transverse process
Shaft-flat segment, broadens towards center then tapers towards eternal end
Width increases then decreases cranial to caudal
Costal groove-houses artery, vein, nerve=sharp caudal border
Cranial border-rounded and thicker
Head articulates with 2 thoracic bodies, tubercle articulates with transverse fovea of thoracic vertebra of same #

Question 3

Anatomical order of ribs

Answer 3

Superior/cranial ribs have acute/right angle between head and tubercle
Central ribs have roughly straight line
Inferior/caudal ribs have head and tubercle at angle to each other
Ribs “fit” within each other
Curves follow each other-if one rib margin “dives” steeply from other, do not go together

Question 4

Siding ribs

Answer 4

In anatomical position, head dorsal and sternal end is ventral.
Tubercle dorso-medial and head points ventro-medial
Thicker border-cranial
Thinner border-caudal
Cranial border can be thinner in more cranial ribs, costal groove is still evident on caudal border-will help with orientation and siding
Head and sternal ends relatively easy to side, isolated shaft pieces can be more difficult

Question 5

Differences in human vs other mammals limb bones

Answer 5

Mammals-more sculpted, joints in particular-more ridges, tuberosities, notches

Question 6

Scapula

Answer 6

Dorso-lateral surface of mammals
Elongated for muscle attachments

Question 7

Subscapular fossa

Answer 7

Medial/internal surface of the scapula
Concave
A few ridges, oblique ridges for attachment of subscapularis muscle and tendons

Question 8

Scapular spine

Answer 8

Dominates lateral/external surface of scapular; divides the bone into cranial (supraspinous fossa) and caudal (infraspinous fossa) halves
Some species have larger infraspinous fossa, some have secondary smaller spine dorsal to scapular spine
Spine points toward Glenoid fossa

Question 9

Glenoid fossa

Answer 9

Articular joint for the humerus
Ovoid to rounded
Shallower than the acetabulum

Question 10

Supraglenoid fossa

Answer 10

Superior to the Glenoid fossa
Attaches to biceps brachii

Question 11

Infraglenoid tubercle

Answer 11

Inferior to the fossa
Attaches to the triceps brachii/teres minor

Question 12

Acromion process

Answer 12

Dorso-laterally from the spine to the side of the Glenoid fossa
Can be well developed in some species and reduced in others

Question 13

Coracoid process

Answer 13

Cranial to the Glenoid fossa
More developed in some species than others

Question 14

Scapular notch

Answer 14

Posterior to the coracoid process; more notch-like in some species than others

Question 15

Cranial border

Answer 15

Thickens as it progresses medially/dorsally
Both cranial and medial/dorsal borders tend to be thinner than the caudal border, which can be buttressed in some species
Cranial and dorsal borders meet at the cranial angle and the dorsal and caudal borders meet at the caudal angle

Question 16

Siding the scapula

Answer 16

Glenoid fossa is always lateral and spine on external surface
Spine increases in size/thickens and develops flares from lateral to medial side
When fossae are uneven, smaller (supraspinous) is cranial and larger is caudal
Caudal border-thickest border
Looking at spine with caudal border down, Glenoid fossa is on the side the bone belongs (fossa to the right=right scapula)
When looking at the Glenoid fossa, coracoid processes curve more medially/towards the internal surface
With coracoid process up, curves toward the side the bone belongs, or acromion process is on opposite side from where the bone belongs

Question 17

Humerus

Answer 17

Humeral head articulates with Glenoid fossa
Head is rounded and allows for rotation, more ovoid in species that require less rotation
Head oriented more posteriorly in quadrupeds for articulation with downward facing scapula
Lesser tubercle is small projection ventro-medial to head and greater tubercle is large projection dorso-lateral to the head. Between-intertubercular sulcus/bicipital groove
Shaft below tubercles
Nutrient foramen mid-shaft on posterior surface and opens superiorly (blood vessel would run down into foramen)
Proximal half of shaft is more ovoid cranio-caudally in cross section while distal half is more rounded to slightly ovoid medio-laterally in cross section
Deltoid tuberosity on shaft on lateral aspect

Question 18

Humerus pt. 2

Answer 18

Distal aspect=3 fossae; posterior-olecranon: largest and accommodates olecranon process of ulna, can have perforation/septal aperture; anterior-coronoid:on more medial side for coronoid process of the ulna; lateral of anterior surface-radial: for head of radius
On distal, joint that articulates w radius/ulna. Rounded eminence on lateral side: capitulum for articulation with radius and spool-shaped structure on medial side: trochlea for articulation with ulna
Borders of these flanked by lat/med epicondyles, medial more prominent

Question 19

Siding the humerus

Answer 19

At cranial side of shaft w head away from you, w head up, intertubercular groove is on side bone belongs, deltoid tuberosity opposite, muscle ridge swoops down from deltoid tuberosity to medial epicondyle or to side bone belongs
At caudal aspect w head facing you, medial epicondyle elevated in comparison to lat. medial epicondyle/border thicker than lat. at posterior aspect, thinner side is side where bone belongs. On posterior aspect, depression above olecranon fossa slopes down laterally/towards the side bone belongs while trochlea slopes away

Question 20

Radius

Answer 20

& ulna fuse in adults mostly
Radius compressed cranio-caudally. Superior aspect is head-articulates with capitulum. Depression in head-fovea capitis.
Head-ovoid and sometimes very sculpted. Rotation non-essential.
Large head-articulates w both condyles->head w 2 facets, medial larger
On caudal aspect of head is articular circumference for articulation w ulna. Radial tuberosity is inferior to head on medial border, biceps brachii inserts on this

Question 21

Radius cont.

Answer 21

Slightly cranial/anterior to ulna, interosseus crest on medial to posterior/caudal surface. Cranial side of shaft convex and smooth, caudal slightly concave and roughened. Nutrient foramen on medial to posterior surface, opens inferiorly. Shaft of radius consistent through length then flairs at distal end
Distal end articulates with ulna and 2 carpals. Caudal surface is ulnar articulation. Bump on bone opposite this articulation is medial styloid process. Cranial surface-3 grooves, medial:small/oblique w tendon for abductor digiti I longus. Middle groove: wide and vertically oriented and houses extensor carpi radialis, lateral groove: wide, indistinct, vertically oriented and houses common digital extensor

Question 22

Siding radius

Answer 22

Looking at head of the radius with notch down or interosseus crest up, bump of bone/slightly larger side is the side the bone belongs/larger articular surface is on the side it belongs. Divided articular heads-at with ridge of bone between facets going up or interosseus crest down, larger facet on the side.
When looking at interosseus crest with head up, styloid process on opposite side bone belongs and crest is slightly to side it belongs.
Looking at distal articular surface w interosseus crest down, elevated bone of styloid process is on the side.
For artiodactyla (even toed ungulates), looking at distal articular surface with interosseus crest down, slightly convex articular surface with ridge to side the bone belongs.

Question 23

Ulna

Answer 23

Superior aspect dominated by olecranon process, trochlea (semilunar notch) articulated with trochlea of humerus. Anterior has coronoid process-medial and lateral in Somme species-medial larger. Radial notch is articulation for head of radius. Radial head and notch form floor of semilunar notch. Below medial coronoid process is ulnar tuberosity, insertion for biceps brachii
Interosseus crest on lat/ant surface of shaft and roughened
Nutrient foramen is also lat/ant and opens dismally
Distal aspect tapers to lateral styloid process

Question 24

Ulna

Answer 24

Superior aspect dominated by olecranon process, trochlea (semilunar notch) articulated with trochlea of humerus. Anterior has coronoid process-medial and lateral in Somme species-medial larger. Radial notch is articulation for head of radius. Radial head and notch form floor of semilunar notch. Below medial coronoid process is ulnar tuberosity, insertion for biceps brachii
Interosseus crest on lat/ant surface of shaft and roughened
Nutrient foramen is also lat/ant and opens dismally
Distal aspect tapers to lateral styloid process

Question 25

Siding the ulna

Answer 25

Looking at semilunar notch, coronoid projects to side it belongs. Radial notch is opposite side.
At head of olecranon, with semilunar notch up, head leans away from side it belongs
On distal aspect, looking at roughened side with articular surface, styloid process leans to side bone belongs, at smoother side process leans away

Question 26

Forelimb

Answer 26

Familiarity with changes in shape of shafts and orientation of nutrient foramen will help with determining which end is cranial vs caudal in shaft pieces, which can allow you to side them
To help with remembering which direction nutrient foramen open, look at dog lying down. When looking from the front, you can look into nutrient foramen on long bone shafts, or can open towards you.

Question 27

Carpals/metacarpals/phalanges

Answer 27

Less frequently collected in archaeological situations. Reference manuals rarely detail these.
Sesamoid bones also common in many species, appear rounded and do not have any articulations, form in tendon at stress points for extra leverage.
Particularly at metacarpophalangeal joints
In dogs, often additional sesamoid between intermedioradial and Distal I. Also 2 proximal and 1 dorsal at each meacarpophalangeal joint of forepaw and frequently at prox and intermediate phalangeal joint

Question 28

Carpals

Answer 28

Up to 8: radial/scaphoid, intermediate/lunate, ulnar/cuneiform, accessory/pisiform, distal I/trapezium, distal II/trapezoid, distal III/magnum, Distal IV/unciform
Radial and intermediate can fuse: intermedioradial or scapholunate
Distal carpals can also fuse
1st distal carpal smallest, 4th largest
More tightly articulated, less mobility

Question 29

Radial

Answer 29

Largest carpal bone. Large convex fact and on concave side, 3 facets that look like M/W
Siding-looking at convex side with flatter side on thumb, process/nubin up and point to side bone belongs to

Question 30

Ulnar

Answer 30

Next largest. Z shaped. One side concave, other convex
Siding-looking at convex side, bone looks like duck, beak points away from side of bone.

Question 31

Accessory

Answer 31

Has a bulbous end and concave facet at other end
Siding-with bulbous “head” up and bone laying on tape so it doesn’t rock, styloid to the side it belongs

Question 32

Distal carpals

Answer 32

Distal carpals 1-3 progressively larger
Distal carpal 4 is “pyramid” with large concave facet on bottom
Siding-when pyramid is upright and bulbous projection is towards you, bone leans to side/more inclined slope is the side it belongs.

Question 33

Metacarpals

Answer 33

Often 5, but reduced in various species, some only 1. Roman numerals
1st is shortest, 3rd and 4th longest
Base at proximal end, shaft, then head at distal end
Flatter in their cross section than metatarsals
Flatter surface is plantar
Metacarpals shorter/thicker than metatarsals
Head often have raised ridge in center and bases vary
Cow and deer have anterior and posterior groove, anterior deeper than posterior, and deeper on metatarsal than metacarpal

Question 34

Siding metacarpals (dog/coyote)

Answer 34

When looking at base, pinched/plantar surface is down
Hold dorsal surface up and flat
MC 11 D shaped shaft with medial surface flatter and lateral more rounded, base w shaped. Looking at dorsal, longer side of W is the side, at base forms swoosh/moon towards side it belongs/triangle points to side
MC III has slight W to slightly concave base and from medial/lateral side, very U-shaped. At base, bottom tapers to point and leans toward side
MC IV has convex base at shaft, medial side has slight process. Lateral side distinct L/backwards J facet. At dorsal surface, L facet on side, at base, bottom away from side
MCV J shaped facet on medial side and bony prominence and no articulation on lateral side or side bone belongs

Question 35

Siding metacarpals (cow, deer, horse)

Answer 35

Looking at base with flat side down, base is pinched/smaller articular facet on side it belongs

Question 36

Phalanges

Answer 36

Proximal, intermediate and distal row totaling 14 (thumb has only proximal and distal)
Can be reduces as number of toes/fingers is reduced
Get smaller from proximal to distal
Also comprised of base at proximal end, shaft, and head at distal end
Head have 2 lobes and bases have a 2 lobed indention to accommodate head
Distal phalange often has ungual process-claw/hoof
Sesamoid bones common. Many have 2 on palmar surface of metacarpal-phalangeal joint and/or one sesamoid on velar surface of MC-P or interphalangeal joints