Baleen whales have fibroelastic (connective tissue) penises, similar to those of artiodactyls. Many rodents grow larger on islands, whereas carnivorans, proboscideans and artiodactyls usually become smaller. Evidently these mammals soon evolved into two separate lineages&colon; the mesonychians and the artiodactyls. There are diurnal, crepuscular, and nocturnal artiodactyls. Canthumeryx is an extinct genus of primitive giraffid artiodactyls. Cetancodontamorpha is a total clade of artiodactyls defined, according to Spaulding "et al". In Australia, the marsupial "Chaeropus" also developed hooves, convergent those of artiodactyls. Humans have introduced different artiodactyls worldwide as hunting animals. The Antilocapridae are a family of artiodactyls endemic to North America. The Dichobunidae include some of the earliest known artiodactyls, such as "Diacodexis". The odd-toed ungulates are ungulates that are equally important as Artiodactyls. The rate of increase for artiodactyls (0.74) was about a third that of perissodactyls. Without the Cetacean descendants the Artiodactyls must be paraphyletic. Artiodactyls with cranial appendages first occur in the early Miocene. Compared to other artiodactyls, a pig's head is relatively long, pointed, and free of warts.