The concept of parity type is proposed as a criterion of relationship among members of the Sceloporus aeneus–scalaris complex, with members of S. aeneus being regarded as viviparous and those of S. scalaris, as oviparous. The viviparous S. goldmani is regarded as a relative of S. aeneus, and S. a. subniger is not regarded as intermediate between S. scalaris and S. aeneus. The proposal by Davis and Smith that S. a. aeneus is oviparous and specifically distinct (as S. aeneus) from S. a. bicanthalis (as S. bicanthalis) is rejected. S. aeneus is hypothesized to have a biennial reproductive cycle. S. scalaris slevini auctorum is segregated into two subspecies: S. s. samcolemani subsp. nov. in the Sierra Oriental (northern end), and S. s. slevini sensu stricto in the Sierra Occidental (also northern end) of Mexico and of the adjacent United States.
Smith, Hobart M. and Hall, William P.
"Contributions to the concepts of reproductive cycles and the systematics of the scalaris group of the lizard genus Sceloporus,"
Great Basin Naturalist: Vol. 34
, Article 3.
Available at: http://scholarsarchive.byu.edu/gbn/vol34/iss2/3