Urodela (salamanders)

Question 1

What type of organisms are contained within Urodela? (diet as well)

Answer 1

Salamanders, the most speciose clade is Plethodontidae, they are from the northern hemisphere, carnivorous predators, and they resemble the common ancestor of all crown group Tetrapods more than anurans and caecilians do

Question 2

How many clades of salamanders are contained within Urodela? What are they?

Answer 2

Sirenidae, Ambystomatidae, Plethodontidae, Amphiumidae, Cryptobranchidae, Proteidae, SIX

Question 3

What are the diagnostic features of Urodela? (6)

Answer 3

1-2 pairs of limbs, post anal tail, paedomorphic features are common, lack tympanum membrane, columella bone is surrounded by soft tissue, show patterns of bone formation

Question 4

What are the features of Sirenidae? (5)

Answer 4

Fully aquatic, have forelimbs but no hindlimbs/pelvic girdle, have external gills and lateral line system, may be able to chew 3 dimensionally

Question 5

What are the features of Cryptobranchidae? (6)

Answer 5

Fully aquatic, no external gills, many vascularized skin folds for cutaneous respiration, “baby crying” calls, medium to large body size, small eyes,

Question 6

What are the features of Ambystomatidae? (7)

Answer 6

Two species in Alberta (Ambystoma), some are aquatic but some are fully terrestrial, stout body, robust limbs despite short, distinct tail (caudal fin in aquatic species), lack lacrimal bone, aquatic larvae

Question 7

What are the features of Proteidae? (4)

Answer 7

Necturus/Proteus, prominent external gills, full aquatic, retain small lung, lack upper jaw bone (maxilla)

Question 8

What are features of Amphiumidae? (5)

Answer 8

Internal gills, vestigial fore and hindlimbs, eel like body with costal grooves, stout, no tongue/eyelid or lacrimal bone

Question 9

What are features of Plethodontidae? (8)

Answer 9

no larval stage, no external gills, fully terrestrial, slender body with small limbs (not as robust as Ambystomatidae), have nasolabial groove, no lung, have ballistic tongue, cluster of teeth on the ventral side of the braincase

Question 10

What is reproduction like for Urodelans?

Answer 10

They use internal fertilization and have a variety of methods to deliver pheromones, the males deposit a spermatophore (capsule of sperm supported by gelatinous base) and the females pick it up