Brief intro to vertebrates Flashcards Preview

2nd Year: Animal Biodiversity > Brief intro to vertebrates > Flashcards

Flashcards in Brief intro to vertebrates Deck (11):
1

What is the splanchnocranium?

The facial skeleton, formed from neural crest.

2

What is the chondro/neurocranium?

Supports the brain, formed from neural crest.

3

What is the dermatocranium?

The insides and roof of the skull, formed from ectoderm.

4

What are the 2 hypothesis for the relationships of the agnathostomes?

1. Molecular: the hagfish and lampreys are a clade

2. Morphological: the lampreys and gnathostomes form a clade, the hagfish are a sistergroup (as they do not have a notochord).

5

Describe a hagfish.

A carrion feeder. They produce slime and tie themselves in knots during prey capture and predator evasion.

6

One of the hypotheses for the origin of jaws states that they were formed from the anterior-most gill arches. What was this initially an adaptation for?

Improved gill ventilation, not for feeding.

7

In sharks, the teeth are embedded in the jaw bone. True or false?

False: they are embedded in the flesh.

8

What is the jaw articulation in lissamphibia and lepidosaurs?

Meta autostylic: the upper jaw is fused to the skull. The lower jaw is attached via the quadrate and articular.

9

What is the jaw articulation in mammals?

Craniostylic: lower jaw is fused to the braincase via the squamosal and dentary.

10

What are the 'adductor mandibulae'?

Jaw-closing muscles.

11

What is the jaw articulation in fish?

The hyomandibular attaches the lower jaw to the braincase.