Vertebrate Skull
Vertebrate Skeleton
Evolution of Locomotion
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Muscle
100

The ancestral skull condition, this type features no fenestrae. 

What is the anapsid skull?

100

In the earliest vertebrates, this was the major structural support for the body. 

What is the notochord?

100

In this form of foot posture the bones of the phalanges lie flat on the ground, while the metatarsals (or metacarpals) and tarsals (or carpals) are raised.

What is digitigrade foot posture?

100

This type of cell breaks down endochondral bone. 

What is an Osteoclast?

100

These types of muscles use anaerobic glycolysis to produce ATP, it creates lactic acid and the muscles are fatigued easily.

What are fast twitch muscles?

200

This adaption in mammals allows for the use of the jaws in different functions without interrupting breathing. 

What is the secondary palate? 

200

A disproven hypothesis for how fins evolved, it does not explain the pelvic girdle or the dermal bone ring that forms it. 

What is the Gill Arch Hypothesis?

200

This posture, found in early tetrapods, required constant flexion in order to hold the body up, and was very energetically costly in contrast to derived tetrapod posture. 

What is splayed posture?

200

This type of bone begins as cartilage, and is formed by osteoblast cells. 

What is endochondral bone?

200

Migratory birds have a high concentration of these types of muscles.

What are slow twitch muscles?

300

Arising from the first ceratobranchial, mandibular cartilage, then articular, this inner ear bone first appeared in the mammals. 

What is the Malleus?

300

This group of tetrapod ancestors were the first to posses ossified vertebral elements with an intercentrum and a pleurocentrum. 

What are the Sarcopterygians?

300

This method of locomotion led to the evolution of a horizontal caudal fin in modern cetaceans. 

What is dorsal-ventral flexion?

300

This is the only remaining dermal bone element present in modern mammals. 

What is the clavicle?

300

This foramen present in avian species allows for attachment of pectoral flight muscles. 

What is the foramen triosseum? 

400
The intermediate state between ancestral and derived tetrapod nares, the position of this creature's nares, between the maxilla and premaxilla, was a result of a drop of oxygen levels in the Devonian period. 

What is Kenichthys?

400

This early tetrapod exhibits a direct connection between the axial skeleton and the pelvic girdle, which played an important role in the hind limbs supporting the body. 

What is Acanthostega?

400

Animals with this type of locomotion posses short, broad limbs, fusiform bodies, and low gear limb levers.

What is fossorial locomotion?

400

This type of bone does not begin as cartilage, and instead directly from non-cartilaginous precursor cells. 

What is intramembranous bone?

400

Myofilaments make up these structural elements of muscle, which all contract concurrently to shorten the muscle. 

What is a sarcomere?

500

Found in Lizards, this adaptation allows for easier grip on prey because of the loss of the lower temporal arch. 

What is cranial kinesis?

500

These small processes on the terrestrial vertebrate vertebrae interlock to prevent excessive twisting.  

What are zygopophyses?

500

Animals with this method of locomotion are adapted for speed, and often have a reduced or absent clavicle. 

What is cursorial locomotion?

500

This type of intramembranous bone is formed in ligaments as a result of stress or friction. 

What is sesamoid bone? 

500

Cardiac muscle, smooth muscle, and skeletal muscle. 

What are the 3 major types of muscle?

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