Ambystomatidae

Collecting ducts that anastomose before interacting with the cloaca or Wolffian ducts (character 2, state 1) either evolved twice on the branches leading to the Ambystomatidae + Dicamptodontidae + Salamandridae and Amphiumidae + Plethodontidae, or once on the branch leading to the Ambystomatidae + Dicamptodontidae + Salamandridae + Rhyacotritonidae + Amphiumidae + Plethodontidae with a reversal on the branch leading to the Rhyacotritonidae.

From the limited data currently possessed, Wolffian ducts without ciliated cells (character 8, state 0) could be the pleisiomorphic condition for salamanders, with a Wolffian duct possessing ciliated cells (character 8, state 1) evolving independently on the branches leading to the Ambystomatidae + Dicamptodontidae + Salamandndae and Rhyacotritonidae.

Cloacal tube folds (character 9, state 1) evolved independently on the branches leading to the Ambystomatidae + Dicamptodontidae and the Rhyacotritonidae.

Non-anastomizing collecting ducts (character 2, state 0) were recovered as the ancestral state for salamanders, and collecting ducts that do anastomose (character 2, state 1) may have evolved independently on the branches leading to the Ambystomatidae + Dicamptodontidae + Salamandridae and Amphiumidae + Plethodontidae clades.

The Cryptobranchidae + Hynobiidae, Ambystomatidae Dicamptodontidae + Salamandridae, and Proteidae lineages possess a Bidder's duct, while this characteristic is lacking on the branches leading to the Sirenidae and Amphiumidae + Plethodontidae + Rhyacotritonidae.

A cloacal tube lacking folds (character 9, state 0) was recovered as the ancestral state for salamanders, while cloacal tube folds (character 9, state 1) evolved independently on the branches leading to the Rhyacotritonidae and the Ambystomatidae + Dicamptodontidae.

The lack of posterior ventral glands (character 11, state 0) was recovered as the ancestral state of salamanders and these glands (character 11, state 1) may have evolved independently on the branches leading to the Proteidae and Ambystomatidae + Dicamptodontidae + Salamandndae + Rhyacotritonidae + Amphiumidae + Plethodontidae.