Tuesday, March 21, 2017

Livyatan: Beast of the Week

This week we will be voyaging back to the Miocene to observe an amazing whale.  Make way for Livyatan melvillei!

Livyatan was a large, toothed, whale that swam in oceans that covered what is now South America and Australia (likely most of the southern hemisphere given that range) during the Serravalian stage of the Miocene epoch, between thirteen and twelve million years ago.  However, teeth that appear to be from Livyatan, found in Australia are dated at only between five and six million years old, pushing this animal's success much further through time. (If it is, in fact, the same genus, and if not it's still from an extremely close relative.)  Only teeth and parts of the skull have been found, but based on this, experts have estimated the animal's body length to have been between forty four and fifty seven feet long from snout to tail.  The genus name is the Hebrew spelling of the word, Leviathan, which was an enormous sea monster from biblical mythology.  The species name, melvillei, is in honor of Herman Melville, the author of the classic novel, Moby Dick...which is about a huge whale...in case you didn't know.

Livyatan immobilizing a young megalodon shark.  Painting by Christopher DiPiazza.

Livyatan was in the same major family of whales as the modern Sperm Whale.  Sperm whales (which Moby Dick was based on) are the largest living toothed whales.  However, they only have teeth on the lower jaw.  Sperm Whales eat almost exclusively giant squid.  Unfortunately we don't know exactly how they hunt because a Sperm Whale has never been observed in the act due to the fact that they dive down too deep, where the squid live, for us to observe the hunting behavior.  We know large squid make up most of their diets, however, because humans used to hunt Sperm Whales for their oil and during dissection/butchering, squid have always been found upon cutting open the stomach.  We also see scars and marks from giant squid tentacles on the faces of many Sperm Whales from their prey fighting back before being consumed.

Livyatan, on the other hand, despite being a close relative to Sperm Whales, may not have behaved, let alone, hunted the same way as their modern family members.  One very striking difference is that Livyatan had proportionally larger, more robust teeth, and a full set of them at that, on the lower and upper jaws.  Some of these teeth measure fourteen inches long!  This suggests it was not a squid specialist.  The fact that the teeth are so large and thick, points to Livyatan being more of a hunter of larger, more general prey that it would utterly pulverize via monstrous bites.  This makes sense, since we know Livyatan coexisted with plenty of other large sea creatures, including seals, sea lions, sharks, dolphins, and slightly smaller whales.  That's right, Livyatan, may have been a hunter of other whales!  (Which isn't unheard of. Orcas do it all the time.)   I find it worth noting that Carcharodon megalodon, (the giant predatory shark that is most certainly NOT still alive today, despite what Discovery Channel's idiotic shows suggest) was a contemporary of Livyatan's.  It is likely that the two were competitors, being similarly-sized predators.  They may have even preyed on each other depending on the circumstances!

Cast of Livyatan's skull on display at the Museo di Storia Naturale e del Territorio, in Italy.

The rest of Livyatan's skull was shaped similarly to that of a modern Sperm Whales.  This suggests that in life it had a large mass of soft tissue taking up most of the front of it's head, called a spermaceti organ.  This body part is full of oil and fat that helps whales use echolocation to navigate underwater.  Because of this it is likely Livyatan could do the same.  It also probably used complex vocalizations to communicate to members of its own species, as well.

I did this quick sketch just to show how much of a whale's head can be soft tissue compared to the skull.  The Sperm Whale's (pictured on the left) iconic rectangular profile is due to soft tissue mostly. (I actually botched the Sperm Whale's profile.  The shaded blue soft tissue part should go beyond the tip of the jaws even.)  It is likely, judging by the skull, that Livyatan, pictured left, had something similar. 

That is all for this week!  As always comment below or on our facebook page!


Lambert, Olivier; Bianucci, Giovanni; Post, Klaas; de Muizon, Christian; Salas-Gismondi, Rodolfo; Urbina, Mario; Reumer, Jelle (1 July 2010). "The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru Nature466 (7302): 105–108. 

Norris, K.S. & Harvey, G.W. (1972). "A theory for the function of the spermaceti organ of the sperm whale". In Galler, S.R; Schmidt-Koenig, K; Jacobs, G.J. & Belleville, R.E. Animal orientation and navigation. NASA, Washington, D.C. pp. 397–417.

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