Because my inner paleontology nerd needs to come out...
I always find it funny when people think that fossilized dinosaur bones are the actual bones of the animal in question.
The clue is in the word "fossil" which means all of the organic material has been replaced by minerals.
Fossilization can occur in various ways, but whether we're talking permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, or in very rare and exceptional cases, fossilization of soft tissues and organic microstructures, rest assured, it's not the actual organic matter that was there, that has long since decayed.
People also find it funny when I point out that most of the mounts in museums aren't actual fossils (which are indexed and reserved for scientific research, with some exceptions like Sue) but plastic casts of the actual fossils. Simply put, it's much safer to display a plastic cast made from the actual fossil than it is to display the actual fossil.
First, you want to leave the actual fossils for study and research.
Second, actual fossils are really fragile, so much so that mere sneezing can destroy thousands of hours of work, and something priceless.
Also, there's no extracting DNA from dinosaur fossils, either, or anything older than 6.8 million years, because DNA has a half life of 521 years, meaning, if you do the math, under the most pristine of conditions, it'll take DNA 6.8 million years to completely decay.
Now, if we remember, all non-avian dinosaur fossils at their youngest are 66 million years old. There ain't no DNA left, no one's ever squeezed blood from a dinosaur fossil, at best, all we've found is molecular microstructures that were preserved in exceptional conditions.
Furthermore, the products of DNA, such as proteins and stuff, aren't the same thing as DNA, something I've pointed out in news outlets that really should know better.
So we haven't found ancient hominid DNA either, at best we have proteins made during DNA transcription, or traces of that.
This problem is further compounded by morons who think mammoths are dinosaurs.
Not every ancient, extinct paleo-fauna is a dinosaur. A dinosaur is a specific categorization of avemetatarsalians that share a common ancestry between Triceratops and modern birds.
That means all birds are dinosaurs, but not all dinosaurs are birds, and anything that doesn't share this ancestry can't be called a dinosaur.
Which means, no, Mosasaurus isn't a dinosaur, nor are plesiosaurs or pterosaurs, either. Pterosaurs are more of a sister group to dinosaurs since pterosaurs are also avemetatarsalians, so I kinda see why people confuse them with dinosaurs and call them "flying dinosaurs."
Mosasaurs, though, actually are part of the order, Squamata, which contains your true lizards and snakes, and their ancestry shows that they share a common ancestry with varanids/monitor lizards.
Sorry, lot of this was on my mind, carry on!