Phylogenetic analysis of 18S rRNA and the mitochondrial genomes of the wombat, Vombatus ursinus, and the spiny anteater, Tachyglossus aculeatus: increased support for the Marsupionta hypothesis.
Janke A, Magnell O, Wieczorek G, Westerman M, Arnason U. J Mol Evol. 2002 Jan; 54(1):71-80.