Terrestrial Feeding

Question 1

What is different about feeding on land vs. in the water?

Answer 1

In water - suction-based feeding mechanism where they expand their mouth and allow water flow to push or “suction” food into their mouth.

On land - tongue and jaw movements are used to push food into their mouth.

Question 2

How feeding on land vs in water relate to the development of the tongue in tetrapods?

Answer 2

Linguistic feeding is neccessary for terrestrial animals to move food into their mouth since they cannot rely on water or air as seen in the suctioning-methods

Question 3

What is meant by lingual (projectile) food acquisition, and how does the hyoid (hyobranchial) apparatus facilitate it?

Answer 3

• Lingual food acquisition is with the assistance of a tongue.
• The hyobranchial apparatus facilitates this mechanism when the accelerator muscle contracts against the lingual process and triggers the tongue to shoot out.

Question 4

Using two examples, explain how feeding mechanisms differ in lingusitc feeding.

Answer 4

Chamelons - Protraction & Retraction
Toads- Flipping in & out

Question 5

What is special about mammalian dentition?

Answer 5

• Thecodont (teeth enclosed in deep sockets),
• Heterodonts (different teeth), and
• Diphyodont (two generations of teeth).
• Tooth formula to categorize the number of teeth seen in mammals as follows: divide the number of incisors, canines, pre-molars, and molars seen on top and bottom and multiply by 2.

Question 6

Explain the tooth formula for mammalian dentition?

Answer 6

Categorizes the number of teeth seen by dividing the number of incisors, canines, pre-molars, and molars seen on top and bottom and multiplying by 2.

Question 7

What is unique about mammalian feeding?

Answer 7

Mastication of food by chewing it all up with salvia and utilizing tongues to position food in the mouth and proceed to shove it all back into the pharynx to digest.

Question 8

What is cranial kinesis?

Answer 8

Movements within the skull (other than the jaw joints).

Question 9

Explain cranial kinesis in lizards and the functional significance

Answer 9

• Mesokinesis: Allows the snout to pivot up and down creating a vertical motion
• Streptostyly: Allows the snout to move side to side
• Effective for effectively capturing and consuming prey.
• Allows lizards to exert more force when biting down their prey.
• Effective for effectively capturing, immoblizing, and consuming prey.

Question 10

Explain cranial kinesis in birds and the functional significance

Answer 10

• Prokinesis: Allows the upper beak (maxilla) to move independently from the rest of the skull upward and downward motion
• Streptostyly: Allows for the upper beak (maxilla) to move independently from the rest of skull side to side
• Allows birds to have a wider and taller mouth opening to capture and consume prey.

Question 11

What unusual features in lower jaw movement appear in the feeding of the gray short-tailed opossum, as studied by XROMM?

Answer 11

• Hyperkinesis: wide and flexible range of motion during feeding
• Allows lateral movement, usually not seen for lower jaw movement in mammals.
• Allows effiective capture and consumption of prey making them great hunters.