Pan-Osteichythyes

Question 1

Original of Teeth

Answer 1

Gnathostome synapomorphies, derived feeding mechanism, controversial origin

Question 2

Components of odontode

Answer 2

Denting core, enamel cap, secured to a ‘bone of attachment’

Question 3

Teeth - Basic Distinctions

Answer 3

Marginal, Palatal, and Pharyngeal Teeth

Question 4

Character of Marginal Teeth

Answer 4

Teeth along jaw margin like PTQ, MC or maxilla/dentary

Question 5

Characteristics of Palatal Teeth

Answer 5

Root in oral cavity
Not common in gnathys

Question 6

Characteristics of Pharyngeal Teeth

Answer 6

Role of endoderm?
Teeth along gills?
- 1st arch is where teeth originate

Question 7

Polyphyodont vs Diphyodont

Answer 7

Poly: continual replacement, plesiomorphic condition
Di: one set of replacement, two sets of teeth

Question 8

Gnathostome Stem

Answer 8

-Bone; aspirin; dentin - enameloid exoskeleton
Pterspidomorphs
-stomach (diversified gastro-intestinal tract)
Anaspida & Thelodonts
-hypophysis opens into oral cavity
-paired nasal capsules
-endochondral ossification
Galaespids
-perichondral ossification
-cellular dermal bone
-epidermal tail
-sclera ring
-paired, pectoral appendages
Osteostracans
-JAWS
“Placoderms”
Gnathostome

Question 9

What are Ostracoderm?

Answer 9

General term describing stem Gnathostome that were jawless armored fish, but is now broadly paraphyletic

Question 10

What are Placoderms

Answer 10

Stem gnathostomes with jaws
- Brindabellaspids
- Antarchs

Question 11

Even more Gnathostome Synapomorphies (Ear Section)

Answer 11

3 Semicircular Canals in the Vestibular Component of Inner Ear
- In placoderms, the bony features were considered osteichthyan, but is now gnathostome characters since CHondrichtyes lost bone, so it’s a derived condition

Question 12

Crown Osteichthyes (435 is defined by he split between

Answer 12

Actinopterygia (ray finned) and Sarcopterygia (lobe finned)

Question 13

What happens along the stem between Gnathostomata and osteichthyes?

Answer 13

-increasing complex opercular, dynamic pharynx, air bladder as paired diverticulum of foregut (lung!)
**REDUNDANCY: gill and lungs for breathing; pathway to specialization

Question 14

Sarcopterygian Synapomorphies

Answer 14

-Lobe fins
-Cranial Fissure
- Reduced opercular/gular series

Question 15

What are lobe fins?

Answer 15

A Sarcopterygian synapomorphies part of the proximal skeleton of LPM.
-Isn’t used by Actinisia for propulsion
- Stabilizing and steering (autapomorphic?)

Question 16

What is the cranial fissure?

Answer 16

Intracranial joints
Basically facilitates the kinetic skull
- wider gape

Question 17

What is meant by reduced opercular/gular series?

Answer 17

Sacropterygian synapomorphy where there is a reduction of bones covering the gills and throat

Question 18

Information about Pan-Actinisia’s apomorphies?

Answer 18

Crown inside Sarcopterygian and its autapomorphies include crazy growth trajectories of neurocranium/brains
- fat filled
- notochord enlargement

Question 19

Crown Choanata (413) is defined by the split between

Answer 19

Dipnoi and Tetrapoda

Question 20

Crown Sarcopterygia is defined by the split between

Answer 20

Choanata and Actinistia

Question 21

Crown Dipnoi

Answer 21

• 6 extant species
• carnivorous
• shallow water
• highly derived teeth
• retain gills
• single, dorsal lung

Question 22

What are choanae?

Answer 22

interna; nares, basically nasal openings

Question 23

Differences in choanae between Sarcopterygia and choanates?

Answer 23

Sarcoprtyergia
- plesiomorphic
– anterior and posterior nasal openings (both external)
– nasal cavity + olfaction separated from breathing

Derived condition for choanates
- Posterior openings = internal (choanae)
- links olfaction to breathing and feeding
- -nasal cavity connected to pharynx