MSCI 324: Comparative Anatomy of Tetrapods Intro

Anatomical features (mostly bones) common to all tetrapods

Superior

Anatomical direction referring to the “head” end of an organism.

Medial

An anatomical direction going toward the middle line of an organism’s body.

Lateral

Anatomical direction going away from the middle line of an organism’s body.

Proximal

The anatomical direction on a limb which leads to its point of attachment/the main body.

Distal

Anatomical direction on a limb leading away from its point of attachment/the main body.

Anterior

The anatomical direction describing the front/underside of an organism.

Posterior

The anatomical direction which describes the back or topside of an organism.

Inferior

The anatomical direction which is away from the head, i.e. at the opposite end.

Cephalic

Alternative term for the anatomical direction going toward the head.

Caudal

Alternative term for the anatomical direction which goes away from the head.

Ventral

Different term for the anatomical direction for the front/underside of an organism.

Dorsal

Alternative term for the anatomical direction of the back or topside of an organism.

Quadrupedal

An organism that walks on four legs.

Bipedal

Organism that walks on two legs.

Appendage

A structure that is attached to the main body.

Axial Skeleton

The part of the skeleton composed of bones in the core body, like the skull, ribcage, and vertebra.

Appendicular Skeleton

A part of the skeleton which consists of appendages.

Ossicles

Inner ear bones.

Atlas

Topmost vertebra.

Axis

Second topmost vertebra, forms joint connecting skull and spine.

Cervical vertebrae

Top section of vertebrae, usually 7 in number.

Thoracic vertebrae

Long section of vertebrae, making up the upper back of the organism.

Lumbar vertebrae

Relatively short section of vertebrae, forms the lower back.

Sacrum

A structure composed of fused vertebrae, the base of the spine.

Coccyx

The base of the tail, or a vestigial tail structure.

Mandible

Lower jawbone.

Maxilla

Upper jawbone.

Nasal bone

Bone which forms the bridge of the nose.

Auditory bulla

Hollow, rounded structure in the skull partly enclosing the middle and inner ear.

Supraorbital process

A bony elongation located above the eye socket

Zygomatic arch

Bridge of bone extending from the temporal bone (side of the skull) to the maxilla.

Sagittal crest

Ridge of bone running lengthwise along the midline at the top of the skull.

Sternum

Long, flat bone located in the center of the chest.

Manubri sterni

Upper part of the sternum.

Xiphoid process

Cartilaginous extension of the lower part of the sternum.

Keel

Extension of the sternum found in birds.

Clavicle

Bones that stretch ventrally across the shoulders, help form the shoulder girdle.

Scapula

A pair of bones that lie dorsally along the chest cavity, help form the shoulder girdle.

Humerus

Long bone in the upper arm that runs from the shoulder to the elbow.

Radius

One of two bones that makes up the forearm, on the lateral side.

Ulna

One of two bones that makes up the forearm, on the medial side.

Carpals

Bones of the wrist, connect the bones of the forearm to hand bones.

Metacarpals

Bones of the hand.

Phalanges

Bones of the fingers.

Ilium

Large, broad pair of bones forming each half of the pelvis.

Ischium

Curved bone forming the base of each half of the pelivs.

Pubis

Pubic bones, at the front of the pelvis.

Femur

Superior bone in the leg, forms the thigh.

Patella

The knee cap, protects the joint between the upper and lower leg bones.

Tibia

Larger of the two bones in the lower leg, connected to the knee and ankle joints.

Fibula

Smaller of the two bones in the lower leg, supports the tibia.

Calcaneus

Bone of the tarsus which constitutes the heel in primates and the hock in some other species.

Tarsals

Short, angular bones that make up the ankle.

Metatarsals

Five bones that make up the feet.

Phalanges (feet)

The bones that make up the toes.

Plastron

Ventral side of a turtle’s shell.

Carapace

Dorsal side of a turtle’s shell.