Livyatan Melvillei

Livyatan Melvillei (image painted by Balazs Petheo)

Behold the terrifying ocean monster, Livyatan Melvillei! This predatory toothed whale lived 12-13 million years ago during the Miocene epoch and grew to 13.5 to 17.5 meters (45–57 feet) in length. A large adult whale could have weighed up to 50 tons. The extinct megapredator is named for Herman Melville and for the Biblical leviathan (“Livyatan” is from the Hebrew word for Leviathan). The great whale’s family is currently listed as “incertae sedis” which means “status uncertain,” a taxonomical place-holder used when biologists are trying to ascertain a creature’s relationship to other related organisms within a larger order.

Livyatan Melvillei with smaller baleen whale

In terms of body size, the modern sperm whale is probably slightly longer and heavier, but the livyatan had stronger jaws and much larger teeth. Paleontologists describe the mighty creature as having “the biggest tetrapod bite ever found,” which is no trivial matter, since the tetrapods include all mammals, reptiles (like dinosaurs), amphibians, and birds. Of course plankton feeders (like blue whales and whale sharks) have larger mouths, but the sperm whale and the livyatan have more powerful maws filled with large sharp teeth. The 36 centimeter (1.2 foot) long teeth of livyatan are the largest known teeth from the animal world which were used for eating (which is to say the tusks of elephants, walruses, Odobenocetops, and narwhals tusks were larger, but were not used for biting into plants or animals).

Livyatan Melvillei BITING a smaller baleen whale (painting via dino-rider)

Livyatan Melvillei presumably swam the deep blue ocean hunting for seals, dolphins, baleen whales and whatever other sea creature was large enough to command its attention (giant sharks, huge squid, huge fish, and bizarre giant birds?). Like the sperm whale it seems to have had a spermaceti organ in its head although it is unclear if this was used for echolocation, auditory signaling, or aggressive male sexual display (i.e. head-butting).  It must have been quite a (horrifying) sight to see one of these giant monsters biting apart a 10 meter (33 foot) long baleen whale. Sadly, the ever-changing dynamic of ocean life caused the great toothed whale to go extinct at approximately the same time as megalodon, the largest known shark (which was a contemporary of the great whale).  Numerous websites speculate which great animal would have won an ocean duel–which is foolish, since whales are clever animals and thus the obvious victor.

 

The Short-faced Bear

Giant Short-Faced Bear (by Joseph S. Venus)

With the possible exception of the polar bear, the brown bear is the largest land predator on Earth today—which brings up the question of whether there were larger bears alive in prehistory. Amazingly, the answer is a resounding yes!  The short-faced bear (Arctodus simus) lived in North America during the Pleistocene.  It ranged from Alaska down to the Gulf of Mexico.  The huge bears first appeared 800,000 in the past: yet they only died out 12,500 years ago (a time which coincides suspiciously with the proliferation of humans in the Americas).  The largest short-faced bears are estimated to have weighed up to 957 kilograms (2,110 pounds) and they stood 1.5 meters (5 feet) tall at the shoulder.

The short-faced bear derived its name from its broad squat muzzle—a feature which gave the bear an incredibly powerful bite.  Using these powerful jaws the bears could crack open huge bones and gobble up the marrow.  Yet short faced bears also had longer thinner legs and arms than living bears.  The combination of graceful runners’ limbs and bulldog-like muzzle has greatly perplexed scientists.  Was the bear a predator who ran down Pleistocene megafauna and then bit its prey to death, or was it a huge scavenger which wondered across the continent looking for carrion to crack apart with its ferocious jaws.  There is still not scientific consensus about the lifestyle of the immense bear, however what is certain is that the short-faced bear was one of the two largest mammalian land predators known to paleontology (the other contender for the title is the even-more-mysterious Andrewsarchus).

The fossilized skeleton of a short-faced bear at the (amazing-sounding) American Bear Center

The Blue-Ringed Octopus

Woodblock prints of ages past show giant octopuses ripping apart boats and feasting on sailors like popcorn.  These artifacts of ancient sea-lore make for rousing images, but they are quite wrong:  octopuses are fierce and cunning hunters but they present little danger to humans—with a noteworthy exception.  The truly dangerous octopuses are not giant monsters (perhaps the artists of yesteryear were thinking of the mighty giant squid?) but rather tiny jewel-like beauties from the genus Hapalochlaena which includes only three or four species.  Known as blue-ring octopuses the tiny creatures swim in tide pools and shallows of the Indo-Pacific Ocean from Japan down to Australia (where they are most prevalent).  Blue-ringed octopuses live on shrimp, crabs, minnows, and horseshoe crabs.  They are tremendous hunters who use camouflage, stealth, and guile to catch their prey.  However, these tools pale before their greatest weapon: the little octopuses are among the most poisonous creatures on planet Earth.

(photo by Aluki from Flickr)

Like the flamboyant cuttlefish, the blue-ringed octopus does not like to bite without giving warning but advertises its toxicity with vivid coloration.  The octopus can conceal itself with tremendous prowess however, as soon as it becomes aware of a predator or some other threat, it dials up its coloration changing from muted reef tones to brilliant yellow with iridescent blue rings.  If you see something like this in the ocean, for heaven’s sake don’t touch it.  The octopus’s warning colors let ocean predators know to leave it alone but immediately attract humankind’s magpie urge to grab shiny things.  Although blue-ringed octopuses are good natured and have been known not to bite people who were provoking them rather intensely, their bites have caused more than seventy recorded fatalities in Australia. The octopus has a tiny beak and often a victim does not realize they have been bitten until they began to fall into paralysis and their respiration starts to fail.

Argh, I said don't touch it

The venom of the blue ringed octopus is a complicated pharmacological cocktail which includes tetrodotoxin, 5-hydroxytryptamine, hyaluronidase, tyramine, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine. The most active ingredient tetrodotoxin blocks the sodium channels which conducting sodium ions (Na+) through a cell’s plasma membrane.  This causes total paralysis for the octopus victim, however if clever and persistent rescuers are present at the time of the bite they can rescue the unfortunate soul with continuous artificial respiration.  This is no small matter as bite victims are often rendered completely unresponsive by the paralytic victim.  Although completely conscious they are unable to communicate in any way or even breathe.  If artificial respiration is initiated immediately and continued until the body can metabolize and eliminate the toxin, bite victims can survive (although it sounds like rather an ordeal).

Blue ringed octopuses are tender and solicitous mothers.  The mother octopus lays a clutch of approximately 50 eggs in autumn which she incubates beneath her arms for about six months (during which time she is unable to eat).  When the eggs hatch, the mother octopus dies. The baby octopuses reach sexual maturity in about a year.  Despite their cleverness and beauty, the animals are as ephemeral as they are deadly.

Under its mother's watchful eye a baby southern blue-ringed octopus (Hapalochlaena maculosa) emerges from its egg.