In short, no, No, NO, FUCK NO.
I've heard this before. McMenamin is a fringe lunatic who has been going on about this alleged "Triassic Kraken" for at least four years now despite everyone else in paleontology recognizing it as nonsense.
There actually was no fossil evidence of this monster, and McMenamin's reasoning is based entirely on the fact that rows of ichthyosaur vertebrae, as preserved, look like cephalopod arms with suction cups. He somehow thinks the most reasonable explanation for this is that a giant squid arranged them deliberately as a self-portrait.
Pharyngula had the following to say about it when it first came up back in 2011 (
source):
Let me explain something here. This “Triassic kraken” has not been found; no fossils, no remains at all, no evidence of its existence. It is postulated to have been large enough to hunt and kill ichthyosaurs, which is remarkable—comparison to modern giant squid is invalid, since they are prey of whales, not predator. This fossil bed is being over-interpreted as a trace fossil, with the bones arranged by intent, by an intelligent cephalopod, which they have not seen. Furthermore, a line of discs is being seen as a picture of a cephalopod tentacle, classic pareidolia. This is trivial: dump a pile of Necco wafers on a table, and I’ll see a picture of squid suckers. This is a whole series of tenuous and unlikely speculations stacked together to make an ultimately ridiculous hypothesis.
After I read the abstract and realization settled in that this was nonsense, something else was nagging me. That name, McMenamin — I’d heard it somewhere before. A little search, and there it was: I’ve encountered him tangentially before. He’s the geologist who so effulgently endorsed the imaginative pattern-spotting of Stuart Pivar. He also claims “that mariners of ancient Carthage made it to America long before Eriksson and Columbus, some time around 350 BC.”