Cytogenetic and Phylogenetic Studies in Carnivora

Abstract

Let us look at the carnivores from the point of view of their presently accepted taxonomy and phylogeny and see how the study of their chromosome constitution fits with the accepted scheme, or where it may give us something new to consider. The earliest Carnivora were the creodonts which appeared in the Paleocene about 75 million years ago. By the Eocene, 60 million years ago, a branch called the Miacidae was flourishing. The creodonts subsequently became extinct, but toward the end of the Eocene the Miacidae diverged into three major branches of the Carnivora (Fig. 1*): these are first the Feloidea, which include the cats, the hyenas, and the mongooses and civets; the second the Canoidea, which include the raccoons, bears, dogs, wolves and foxes, and the weasels, minks, martens, badgers, skunks and otters; and the third the Pinnipedia or marine carnivores, which include the walruses, seals and sea lions. The Pinnipedia are, today, generally not included with the Carnivora but are placed in a separate Order. They did, however, arise from the Canoidea and still retain close serological (Leone and Wiens, 1956; Pauly and Wolfe, 1957) and chromosomal relationships. The latter can be seen in the figure by comparing the diploid number, fundamental number and marker chromosomes with those of the Canoidea.