When one reads about Tyrannosaurus and Brontosaurus, one is not dealing with species, like lions or African elephants. Instead, these are genera, a group of animal species. For example, the lion is in the genus Panthera. Species of Panthera include the lion Panthera leo, the tiger P. tigris, and the leopard P. pardus, among others. So saying Tyrannosaurus is much like saying "the big cats".

To a fair extent the Tyrannosaurus species are the tyrannosaur's of tyrannosaurs; they have taken to an extreme the development of skull size, strength, and power. This and the larger, more forward-pointing mid-upper jaw teeth suggest a more potent wounding ability than the albertosaur's. The stoutness of Tyrannosaurus relative to albertosaurs is readily apparent in the skeletal restorations. They are not as graceful, but they have a well-proportioned, majestic attractiveness of their own.

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Alas, producers of commercial dinosaur products continue to churn out low quality product that is either obsolete or improperly derivative. Dino documentaries and books have become so plentiful that they are no longer special and I do not try to keep up with them. There are also serious problems with quality and accuracy which often fail to meet the expectations of scientists. More about those problems here. I about kicked in the TV screen when one dino doc claimed that the brain of Tyrannosaurus was as large as that of a gorilla when its IQ was not all that much better than a croc’s. And why are the theropods shown pausing to challenge their prey before they charge, when the actual focus of predators is to hit and overwhelm the victim before it knows what is happening? The low standards are not surprising considering how the media and press frequently carry product that promotes belief in the paranormal. But these are quibbles. Dinosaur science has almost completely transformed over the half century that my neural network has been aware of it. The old stand-bys from Allosaurus to the always strange Stegosaurus are still fascinating, but we now know about armored sauropods, fat-bellied therizinosaurs and multi-winged, near avian, sickle claws. The reptile model is out and the avian-mammalian is dominant.

Although some dinosaurs may have spent some time feeding in the water like moose or fishing cats, at most a few became strongly amphibious in the manner of hippos, much less marine as per seals and whales. The only strongly aquatic dinosaurs are some birds. The occasional statement that there were marine dinosaurs is therefore incorrect - these creatures of Mesozoic seas were various forms of reptiles that had evolved over the eons.

The dinosaur world I grew up in was classical. They were universally seen as scaley herps that inhabited the immobile continents. There was no hint that birds were their direct descendents. Being reptiles, dinosaurs were cold-blooded and rather sluggish except perhaps for the smaller more bird-like examples. They all dragged their tails. Forelimbs were often sprawling. Leg muscles were slender in the reptilian manner. Intellectual capacity was minimal, as were social activity and parenting; the Knight painting of a Triceratops pair watching over a baby threatened by the Tyrant King was a notable exception. Hadrosaurs and especially sauropods were dinosaurian hippos, the latter perhaps too titanic to even emerge on land, and if they did so were limited by their bulk to lifting one foot of the ground at a time. Suitable only for the lush, warm and sunny tropical climate that enveloped the world from pole to pole before the Cenozoic, a cooling climate and new mountain chains did the obsolete archosaurs in, leaving only the crocodilians. Dinosaurs and the bat-winged pterosaurs were merely an evolutionary interlude, a period of geo-biological stasis before things got really interesting with the rise of the energetic and quick witted birds and especially mammals, leading with inexorable progress to the apex of natural selection: Man. It was pretty much all wrong. Deep down I sensed something was not quite right. Illustrating dinosaurs I found them to be much more reminiscent of birds and mammals than of the reptiles they were supposed to be. I was primed for a new view.

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Novelist Michael Crichton wrote Jurassic Park as a screenplay option for the Steven Spielberg flick. I am ambiguous about Crichton’s body of work, as it includes dubious anti-scientific elements. But I can’t be too upset about a fellow who includes me in the acknowledgements of his bestselling novel. I ended up doing some preliminary studies of Tyrannosaurus and Deinonychus for the movie(s). These were significantly altered by Spielberg and Stan Winston and his effects team for copyright purposes. In the film, some of my skeletals show up posted on Sam Neill's (ak.a. Dr. Grant's) trailer wall. I was accidentally responsible for the avian term 'raptor' being improperly applied to dromaeosaurs. In another Hunteria paper and PDW, I synonymized Deinonychus with Velociraptor, which Crichton picked up on and shortened into the convenient handle 'raptor'. The movie was okay, but I will never forgive them for presenting Brachiosaurus as such a heavy limbed clunker. I had nothing to do with that. I thought it was too bad the potentially omnivorous brachiosaurs – which were unlikely to have been as placid as cattle – missed the opportunity to snarf up the bratty kids when they were up in the tree.

When it was assumed that birds did not evolve from dinosaurs, it was correspondingly presumed that their flight evolved among climbers that first glided and then developed powered flight. This has the advantage that we know that arboreal animals can evolve powered flight with the aid of gravity, as per bats. When it was realized that birds descended from deinonychosaurs, many researchers switched to the hypothesis that running dinosaurs learned to fly from the ground up. This has the disadvantage that it is not certain whether it is practical for tetrapod flight to evolve among ground runners working against gravity.
The characteristics of birds indicate that they evolved from dinosaurs that had first evolved as bipedal runners, and then evolved into long armed climbers. If the ancestors of birds had been entirely arboreal, then they should be semiquadrupedal forms whose sprawling legs were integrated into the main airfoil, like bats. That birds are bipeds whose erect legs are separate from the wings indicates that their ancestors evolved to run.

Dinosaurs seem strange, but that is just because we are mammals biased toward assuming the modern fauna is familiar and normal, and past forms are exotic and alien. Consider that elephants are bizarre creatures with their combination of big brains, massive limbs, oversized ears, teeth turned into tusks, and noses elongated into hose-like trunks. Nor were dinosaurs part of an evolutionary progression that was necessary to set the stage for mammals culminating into humans. What dinosaurs do show is a parallel world, one in which mammals were permanently subsidiary, whereas the dinosaurs show what largely diurnal land animals that evolved straight from similarly day-loving ancestors should actually look like. Modern mammals are much more peculiar, having evolved from nocturnal beasts that came into their own only after the entire elimination of nonavian dinosaurs. While dinosaurs dominated the land, small nocturnal mammals were just as abundant and diverse as they are in our modern world. If not for the accident of the later even, dinosaurs would probably still be the global norm.

The biggest living terrestrial predator, the Siberian tiger, at about a third of a metric ton (300 kg) pales in comparison to the biggest of the meat-eating dinosaurs, which reached 5 to perhaps 20 metric tons - the size of elephants and bigger. But while elephants cannot run, the biggest predatory dinosaurs probably ran as fast as horses, and they hunted herbivores that themselves were as big as or bigger than elephants.

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What gave archosaurs the edge as large predators at this time, and therapsids the edge as smaller ones? Frankly, I am not sure. Both seem to have had heightened metabolic rates and fur or feather insulation... Perhaps the chief advantage enjoyed by thecodonts centered around their big, slashing attack jaws. These may have made them better big-game hunters, while the more precise cutting teeth of therapsids were more suitable for smaller prey.

Tyrannosaurus rex did not have 6-to-8-inch serrated teeth and an arc of D-cross-sectioned teeth set in a massive, powerful skull just to consume rotting carcasses! These were killing tools. In sharp contrast are the weak beaks and feet of vultures and condors- the only true living scavengers.

[Velociraptors] are among my very favourite dinosaurs. Their long upcurved skulls, slender yet compact proportions, and great sickle claws make these elegant, attractive, yet demonic animals. There is nothing else like them. Pound for pound, these are among the most powerful of known predators; certainly no other theropod had such a combination of foot, hand, and head weaponry... Among theropods only Tyrannosaurus, with its extreme skull strength, equalled Velociraptor in total power relative to weight.