Welcome. This guide covers the basic anatomical differences of forelimb bones among different animals.
If you want to review key osteological features of forelimb bones, visit this link: Identification of Osteological Features of Forelimb Bones of Animals.
Let’s explore the comparative anatomy of forelimb bones in various animals.
Osteological features differ among species. This article examines only the most relevant characteristics.
Forelimb bones of different animals
We will compare the osteological features of the following forelimb bones –
- Scapula bone of ox, sheep and goat, horse, and dog
- Humerus of ox, sheep and goat, horse, and dog
- Radius & ulna of ox, sheep and goat, horse, and dog
- Carpal bones of ox, sheep and goat, horse, and dog
- Metacarpal bones of ox, sheep and goat, horse, and dog
- Digit & phalanges of ox, sheep and goat, horse, and dog
- Sesamoid bones of ox, sheep and goat, horse, and dog
Begin learning and identifying the main differences.
Compare the osteological features of forelimb bones from different animals, such as ox, sheep, goat, dog, cat, and birds. This analysis focuses on ox, sheep, goat, horse, and dog.
Comparative anatomy of scapula bones of different animals
We need to consider the following osteological features for comparing –
Spine of scapula
Divided the lateral surface into unequal halves (ox, sheep, and goat)
Divided the lateral surface into unequal halves (horse)
Divided the lateral surface into equal halves (dog)
Acromion process
Present in ox, absent in horse, and short and blunt in dog; located at the level of the glenoid cavity in dog. (For sheep and goat, similar to ox.)
Supraglenoid tubercle
Smaller in ox, sheep, and goat
Prominent in horse
Blunt in the dog
Coracoid process
Short and rounded in ox, sheep, and goat
Well developed in horse and
Rudimentary in case of a dog
Glenoid cavity
Shallow and circular in ox, sheep, and goat
Deep and oval in the horse and
Shallow and oval in the dog
Glenoid notch
Shallow in ox, sheep, and goat
Deep in the horse and
Shallow in the dog
Subscapular fossa
Shallow in ox, sheep, and goat
Deep fossa in the horse and
Shallow fossa and having a few rough lines in the dog
Comparative anatomy of the humerus bones of animals
We need to consider the following osteological features for comparing –
Shape and size
Shorter and twisted in ox, sheep, and goat
Longer and more twisted in the horse
More long and less twisted in the dog
Deltoid tuberosity
Less prominent in ox, sheep, and goat
More prominent in the horse
Present in the form of a ridge in the dog’
Greater tuberosity
Very large and divided into two portions. Located above the level of the head of the humerus
Larger and divided into two portions. Located at the level of head of the humerus
Small and undivided. Located at the level of head of the humerus
Musculospiral groove
Less prominent in ox, sheep, and goat
More prominent and deep in the horse
Not so prominent in the dog
Supratrochlear foramen
Present only in the cranio-distal portion of the humerus of the dog.
Intermediate tubercle
Present only in horses. The horse has three tubercles at its proximal portion: greater, lesser, and intermediate tubercles. (Ox, sheep, goat, and dog do not have this.)
Comparative anatomy of the radius and ulna bones of different animals
We need the following important osteological features for comparing –
Ulna bone
Fused with the radius at its postero-lateral aspect, except for two interosseous spaces.
Fused up to the proximal third of the radius bone in the horse
There are two separate bones in a dog.
Interosseous space
There are two interosseous spaces in the ox.
There is one (proximal) interosseous space in the horse.
There is space throughout the length of bones in the case of a dog.
Styloid process
Pointed in ox, sheep, and goat
Absent in horse and
Blunt in a dog
Comparative anatomy of the carpal bones of different animals
We need to consider the following osteological features for comparing –
Number of carpal bones
Six in ox, sheep, and goat
Seven or eight in a horse
Seven in a dog
Bones (Medial to lateral aspect)
In ox, sheep, and goat – Proximal row – Radial carpal, intermediate carpal, ulnar carpal, and accessory carpal bones
Distal row – (second and third fused) and fourth carpal bone
In the horse, the Proximal row includes – radial carpal, intermediate carpal, ulnar carpal, and accessory carpal bones
Distal row – (first carpal), second carpal, third carpal, and fourth carpal bones
In the dog – Proximal row – (Fused radial carpal and intermediate carpal), ulnar carpal, and accessory carpal bones
Distal row – first carpal, second carpal, third carpal, and fourth carpal
Comparative anatomy of the metacarpal bones of different animals
We need to consider the following osteological features for comparing –
Number of metacarpal bones
Two (large III and IV fused; small V) in ox, sheep, and goat
Three (small II, Large III, and small IV) in a horse
Five (1st – shorter, third and fourth – larger and second & fifth – equal in length)
Small metacarpal bones
Located at the postero-lateral aspect in ox, sheep, and goat
Located at the postero-lateral and postero-medial aspects of the horse
All five metacarpals are separated.
Intercondyloid cleft
Present only in ox, sheep, and goat.
Depression of the sesamoid bone on the posterior aspect
Four in number in ox (two for each digit)
Two in number in the horse and
Nine in dog (one for the first digit, two for digits two through five).
Comparative anatomy of digits and phalanges of different animals
We need to consider the following features for comparing –
Digit number
Two digits are developed (III and IV) in ox, sheep, and goat.
One digit is developed (III) in the horse.
Five digits are developed (I, II, III, IV, V) in the dog.
Number of phalanges in each digit
Three for each digit in ox and also in horse
Two in the first digit and three in the second to fifth digit in the case of a dog
Sesamoid bone in different animals
Sesamoid bone in each digit of the animal
Three in ox, sheep, goat
Three in a horse
One in the first digit and two for the rest digits in the dog
Sesamoid bone in each limb
Six in ox, sheep, goat
Three in a horse
Fourteen in a dog
Total number of sesamoid bones in the forelimb and hindlimb
Twenty-four in ox, sheep, goat,
Twelve in a horse
Fifty-six in dog
“In the hind limb, there is another sesamoid bone – patella; one on each hind limb of an animal.”
Total number of sesamoid bones in an animal
Twenty-six in ox, sheep, goat
Fourteen in horses and fifty-eight in dogs
Conclusion
This overview provides a foundation for understanding forelimb bone anatomy and helps you identify bones from ox, sheep, goat, and similar species. The information is needed for understanding the comparative anatomy of forelimb bones.
