Life : Yes, but it seems you ignored my point. In fact I tend to think, based on available evidence (Govender et al. 2019, Piazza et al. 2019, Loch et al. SVP 2019), that
Livyatan was most likely restricted to the southern hemisphere, although it is too early and we have too few fossils to say anything conclusive yet.
The reason for this likely has nothing to do with megalodon at all. Megalodon existed in the southern hemisphere as well, alongside
Livyatan, seemingly for several millions of years. In fact Livyatan (and raptorial physeteroids in general) seem to have evolved to fill their niches despite the presence of large members of the
Carcharocles lineage since the late Oligocene. With the recent suggestion (SVP 2019) that Livyatan may have foraged at high latitudes, and previous suggestions that megalodon may not have been suitable for these habitats, it seems increasingly likely that
Livyatan was adapted to colder climates, and that the tropical circle might simply have acted as a dispersal barrier due to that.
But what about your suggestion that that tooth, which was from the US, belonged to
Livyatan (speculation, of course)? Do you think it was restricted to the southern hemisphere, or not? It cannot have been restricted to the southern hemisphere, but "preyed on" in the northern hemisphere at the same time.
1) Do I have to explain how niches and competition work? Another animal evolving while megalodon was in existence is one thing, another apex predator evolving is an entirely different thing. That raptorial physeteroids, including Livyatan, managed to evolve in a sea where the large predator niches were already filled by giant sharks, and successfully managed to challenge those sharks throughout the neogene, is actually quite impressive from an ecological and evolutionary perspective (although it has nothing to do with how the two would compare in a fight).
2) We have no described material. But as I have suggested before, if
Livyatan was a big-game hunter, it is entirely possible that there are cases of
Livyatan predation that have been erraneously interpreted as megalodon predation, for example because
Livyatan was not known when they were last examined.
It is also plausible that due to its geographical range being limited to the southern hemisphere, it was simply not present in the faunas with the best-sampled record of bitten prey items.
3) Yes,
Livyatan’s palaeoecology is poorly understood so far. I hope that will change soon. However, you appear to jump to the conclusion that something not being known automatically translated to it being inferior.
I don’t get what "hype" you are talking about tbh.
Livyatan is far less hyped, in the media, here, or elsewhere, than megalodon. There are no documentaries out there called "whalezilla" as of my knowledge, no popular-scientific books full of questionable claims, not even speculative life-sized models the way there are with meg.
The reason is obvious, just like
T. rex, meg has been known for a long time, and very extensively collected and studied, while
Livyatan is a fairly recent discovery, known from only one substantial find. Such a discovery may get a phase of widespread attention, but it cannot really measure up to the amount of attention and "hype" something that's been known and studied 20 times as long has gotten, and is usually short-lived. In the 90s,
Giganotosaurus was all the rage for a few years, everyone was seemingly waiting in line to author a paper about it, the media were full of sensational reports. A few decades later, there is seemingly so little interest in it that its holotype, one of the most complete giant theropods known, still hasn't even been described.
Actually we have to sincerely hope this whale gets a little more "hype", so that sufficient research and collection efforts are made.
Who here is making any unscientific speculations about the predatory capabilities of
Livyatan? I think everyone acknowledges the lack of data about its prey and ecological relationships. We don't even have a real idea of what it fed on, although to take that as evidence that it was necessarily a less formidable hunter than megalodon is of course fallacious.
What is not hype, but fact, is that this animal was gigantic, and had a gigantic and very formidable set of jaws. No matter how we interpret its ecology, these facts are not going away.
And naturally, what we do know of
Livyatan should be, and is, the point of focus regarding this animal. Not stuff we don't know, and therefore cannot compare.
I certainly agree with some material on this thread giving a "deeply unrealistic projection" of
Livyatan’s capabilities or "strength". For example, comparison of large restored megalodon jaws to the holotype of
Livyatan, with major amounts of forced perspective in them that come from scaling based on the size of people which are several metres further or closer to the camera in the respective shots. Or statements like this, which implies evidence that megalodon preyed on
Livyatan, when such evidence does not exist.
Please refer back to my explanations on bite marks from before. Bite marks that are not healed are not unambiguous evidence for an attack on a living animal like you seem to imply. At best, a large number of such bite marks, or placement particularly indicative of an attack, might provide a decent indication in that direction. A single unhealed bite mark can just as easily be scavenging as it can be predation. Extant sharks scavenge too, so it is not a big stretch to expect that a megalodon that found a
Livyatan carcass (if that really is a
Livyatan tooth, as you claim, and if that thing even really is a bite mark) would have fed on it.
Also, as sam1 correctly points out, the comparison is very lop-sided as it is. For all we know, even if
Livyatan had fed or preyed on megalodon regularly, we would have slim chances of ever finding fossil evidence of this. Moreover,
Livyatan bite marks would probably be a lot more difficult to identify as such than megalodon bite marks, since crushing and blunt fracturing are easily mistaken for preservational artifacts rather than biological traces. Cuts not so much, though I do have to say that that supposed "bite mark" on the "Livyatan" tooth from Georgia could just as easily be from a pickaxe.
As for abundance of
Livyatan fossils, this is again not indicative of anything relating to dominance or ecological success, as you seem to be implying. Shark teeth are simply astronomically more common as fossils because due to their tooth replacement, while a
Livyatan can only lose its teeth/die once.
Grey :
Scaled from the figure you listed assuming the human silhouette is 1.8 m.
