BY DR. JOSE PALU-AY DACUDAO
TO BE brief, the discovery of fossils of the species pakicetus in 1979 began the first serious turnabout of the classification of cetaceans. Pakicetus lived just under 50 million years ago, and had a skull and especially ear bones that placed it directly under cetacea. Yet it had legs, and could walk on land. Furthermore in 2001, more foot fossil discoveries showed that pakicetus had the feet of artiodactyls. Its teeth suggest that it was a carnivore that ambushed animals that came to drink in bodies of water or caught and ate fish.
Later the discovery of the fossils of indohyus, a strange creature that also lived just under 50 million years ago, provided the closest there is to a smoking gun. Indohyus had a foot that was definitively artiodactyl, and do not exist in any other animals but artiodactyls. Yet it had ear bones that were also definitively cetacean, and do not exist in any other animals except cetaceans. Moreover, indohyus had teeth that suggested it ate plants, and had dense bones that indicated it could easily stay underwater. It actually looked like a chevrotain, also called mouse deer, a small extant deer-like artiodactyl native to South East Asia, India, and Africa. Chevrotains live alongside rivers, generally eat leaves and other plant parts, and dive into the river in order to avoid predators. Indohyus probably lived like chevrotains, occupying the same ecological niche.
Moreover, an even more recent study has revealed that the microbial flora of cetacean multichambered stomachs (which as mentioned above can degrade chitin) resemble that of modern ruminants (which can degrade cellulose). It may turn out that cetaceans not only retained the multichambered stomachs of land-living artiodactyls, but many of the stomachs’ microbial inhabitants as well.
At present, cetaceans are regarded as belonging to the same suborder as hippopotamuses, the whippomorpha. Their closest relatives are the ruminants (ruminantia), which includes deer, goats, antelopes, cows, carabaos. Farther off are the pigs (suina). More distant than all of the above, but still under Artiodactyla, are the camelids (yylopoda).
Cetaceans are a wonder. Legs to paddles and tails to flukes, they superficially look like fish, but are warm-blooded mammals that breath air and nurse their young. From one perspective, they are deer that went to sea. Their relatives and ancestors were herbivores, yet they are the most carnivorous of all mammals.
Finally, let’s talk about their brains. Intelligence in mammals are often correlated to the brain to body mass ratio and the convolution of the brain (more twists and turns of the gyri of the cerebral cortex). Humans have brain to body mass ratio of about 1:60. Amazingly, so do oceanic dolphins. No other mammal comes close to this. Furthermore, the brains of these dolphins are more convoluted than those of humans. It’s no wonder cetaceans can transmit components of learned behavior, essentially culture, to their offspring.
If cetaceans had limbs with opposable thumbs, and a vocal apparatus that could support sophisticated speech, I would think that they could possibly build marine civilizations. They would have the brains to do it, and are as sapient as us humans.
Thus, for me, intentionally killing a cetacean, a sapient creature with a brain as large as ours and more convoluted, should be considered murder./PN
