Anthroposaurus
Did the Dinosaurs Develop Intelligence?
Abstract
Contents Updated: Wednesday, December 15, 1999
The greatest intelligence is precisely the one that suffers most from its own limitations.
Anthroposaurus Sapiens
Did the dinosaurs develop intelligence before Adam?
Some dinosaur iconoclasts have dared to ask this question, but even they have merely answered, “They couldn’t have”. Thus Bakker asks:
Why didn’t [the dinosaurs] evolve larger cerebral systems? Why didn’t they eventually produce super-intelligent species capable of making stone tools?
Desmond compares mammals with the superior dinosaurs and wonders, “Why did not "Man" land on the moon in the Cretaceous?” adding that by “Man” he meant a creature filling the ecological role of humans. Sagan asks:
If the dinosaurs had not all been mysteriously extinguished some sixty-five million years ago, would the saurornithoides have continued to evolve into increasingly intelligent forms?
All believe dinosaurs would have reached intelligence were it not for the Cretaceous terminal extinction. And all agree that they failed to achieve it because they died out first.
I disagree.
Some dinosaurs did develop intelligence and by so doing caused the Cretaceous terminal extinction, just as an insensitive ape developed intelligence at the end of the Tertiary and created the mass extinction that marks the end of that geological era. Though the direct evidence is sparse—I give what little there is in the next chapter—the circumstantial evidence is compelling. The thesis is not self-evidently false, as, say, the idea of a flat earth is. Today we consider it evident that the earth is round and revolves round the Sun—but these ideas have only become accepted in the last few hundred years.
The movement of the continents, continental drift, noted by Wegener sixty years ago seems obvious to us all now, indeed it was probably obvious to any child studying a map of the world decades before Wegener, but because continents were so massive and the experts could not think of a mechanism by which they could move, no one was willing to ask the question, “must not South America and Africa once have been joined”?
We might find ourselves realizing simultaneously that the anthroposaur preceded us, and that we have just stumbled over the precipice of our own extinction.
Mankind has adopted its position of global domination in just five million years. The dinosaurs, we have seen, were warm-blooded, active creatures and usurped the rule of the thecodonts in only five million years. Mechanisms exist for species to evolve at astonishingly fast rates. On average a species of dinosaur did not last for more than two or three million years before becoming extinct or evolving into a new species. There is no reason why one of the dinosaurs should not have evolved intelligence during the last five million years or so of the Cretaceous Period.
Dinosaurs evolved quickly and there was a spate of dinosaur evolution just prior to their final decline. Bakker says that the stenonychosaurs were “evolving quickly in many of their adaptive compartments” and with their bulky pair of mid-brain lobes they were probably “every bit as endowed as the Late Cretaceous mammals”.
Fossil dinosaurs have been found with quite remarkably large brains... for dinosaurs. One authority says that triceratops had a brain weighing a kilogram, a fair size compared with our 1.5 kilograms, though its body weight was 9000 kg compared with our 70 kg. Struthiomimus had a brain to body ratio similar to that of a modern day ostrich—1:1000. And, though brain size is obviously a general measure of intelligence, there is no way of telling whether the brain of an extinct class of animals functioned in quite the same way as those of animals with which we are familiar. We cannot be certain that modern creatures with larger brains are more intelligent than the smaller brained dinosaurs. A higher metabolic rate, more active brains, faster synapses, sharper nerve impulses could all contribute to greater efficiency of the brain even though it were smaller than ours.
Of course, size is presumably directly related to memory capacity but, for humans, much of the brain seems redundant, evolution looks to have overshot—a result, perhaps, of sexual selection or a saltagen in a high quantum state. It might not have done for dinosaurs whose memory capacity could have been better adjusted to the capabilities of their brains overall.
Then again the nature of their intelligence might have differed from ours. Many cold-blooded animals do very well in the world of the mammals by using abilities other than intelligence. In South America, farmers use marine toads to suppress mice and rats which otherwise would make a feast of their crops and seeds. A ponderous toad successfully preying on wily rats? Yet they do. The toads, weighing five pounds wait with infinite patience for the cleverer victim to traverse its usual path, it pounces and the rat is gulped whole into the frog’s maw, rendered insensible by poisonous saliva then swallowed. The abilities of dinosaurs might also have developed rather differently from mammals.
But even if dinosaur and mammalian evolution were truly parallel and dinosaurs had to evolve big brains to become intelligent, fast evolution could have done it in a relatively short time. You do not have to believe me. Witness this remarkable paragraph by Adrian Desmond:
The most intriguing Late Cretaceous inhabitants were the intelligent mimics unearthed in recent years—wide eyed ostrich dinosaurs, and dromaeosaurids like deinonychus and the saurornithoides with stereo-vision functionally mated to opposable thumbs. These dinosaurs, capable of more skilful behavioral feats than any other land animal hitherto, were separated from other dinosaurs by a gulf comparable to that dividing men from cows: the disparity in brain size is staggering. The potential in dromaeosaurs and coelurosaurs for an explosive evolution as the Tertiary dawned cannot be doubted—who knows what new peaks the sophisticated “bird-mimics” would have attained had they survived into the “Age of Mammals”. Yet apparently not a breeding population of these beautiful, alert dinosaurs outlived the comparatively cumbersome and dim witted giants.
Desmond almost proposes that the dinosaurs became intelligent but he pulls up at the final hurdle.
Yes the “explosive evolution” did occur. Mankind has evolved from being a user of crude rock tools to our present level of civilization in just one million years. It must be possible that these alert creatures did the same. How would that have looked in the fossil record, especially bearing in mind that the chosen habitat of these dinosaurs made their remains scarce, just as remains of early man are scarce and, of modern chimpanzees, non-existent?
Dale Russell, discoverer of stenonychosaurus, has also postulated that late Cretaceous dinosaurs were well on the way to becoming intellectual animals, and would have succeeded if the dinosaurs had not suffered extinction, stenonychosaurus had an opposable thumb, stood upright about three feet tall and had binocular vision. Russell commented, “it had all the ingredients of success that we see later in the development of the apes”. He believes that stenonychosaurs were the “chief predators on Cretaceous mammals” and that there must have been quite a lot of them because, by the end of the Cretaceous, there were a lot of mammals, though they were small. Nevertheless few have been found as fossils, just as complete fossil mammals from that period are also rare. “The fossil record is so limited that it is a pitiful reflection of past life”, as Norman Myers puts it.
Russell deduced the appearance of a stenonychosaurus that had evolved unhampered by disasters until the 20th century. A model of the creature, a dinosauroid, is on display in Ottawa. The conception of the dinosauroid was based upon convergent evolution. Russell extrapolated trends observable in the dinosaurs like stenonychosaurus to beyond their extinction. By the 20th century, Russell believes their brain size would have been within the human range. To accommodate it its skull would have expanded and its face would probably have flattened. The long dinosaur neck would have shortened to bear more comfortably the weight of its brain. Consequently its tail would have been lost since it would not have been needed to counterpoise the neck and head.
He assumed live births and, rather illogically, that the dinosauroid would therefore have needed a navel. The young, though, were thought likely to have been fed on regurgitated food and the creature would not have had any “mammalia”. Communication would have sounded similar to birdsong. Besides these conjectured features he supposes there would be characteristics typical of dinosaurs such as scaly skin, large oval eyes with vertically slit pupils, absence of external sex organs and a three fingered hand, one digit of which would be opposed.
“Absence of external sex organs”—possibly, but, although the tuatara lizard of New Zealand which is very similar to lizards from 200 million years ago has no penis, the marine iguanas of the Galapagos islands have them. Most reptiles and birds procreate by pushing together their cloacae which are openings in the body doubling up as a sexual tract and an anus. This seems a bit of a hit and miss affair to the intelligent mammal and, if Bakker’s arguments are to mean anything, one would have thought that hot-blooded, sexually active dinosaurs would have evolved a more certain method of procreation. However, if birds are examples of latter day dinosaurs, Russell could be correct, and birds don’t seem to have any trouble in procreating.
Nevertheless, if convergent evolution had required a convergence of shape appropriate for a thinking creature, the upright stance of the human and the ventro-ventral mode of copulation it induces, might have dictated the evolution of a penis in the dinosauroid, if not in other dinosaurs.
We considered some possibility of major differences in the structure of the brain of the dinosauroid and man. In mammals the brain grew by expansion of the cerebral lobes but in birds it was the corpus striatum that expanded. A great deal of visual information processing in reptiles is done in the retina rather than being passed on to the brain. The ostrich mimic dinosaur had enormous eyes protected by bony plates. That is usually attributed to a nocturnal lifestyle but it could indicate that the parts of the brain of the dinosauroid that were to develop were associated with vision.
Russell was almost at pains to emphasize that his guesses were conservative—and that must be true. 65 million years, even in a thought experiment, seems too long for an active, warm-blooded creature already up and running to need to develop what mammals did in the same period of time from a standing start. With the mechanisms for rapid change at the disposal of evolution such a long time scale seems unnecessary if not silly. It is more likely that intelligence evolved before the whole dinosaurian dynasty came to an end.
Russell’s conjectures give us a model, not of the impossible but of the possible. Not of the hypothetical dinosauroid today but the actual anthroposaur of 65 million years ago.
Within a few million years of the extinction of the dinosaurs, the neocortex of the early primates had begun to develop. Quite ordinary mammals now exhibit astonishingly sophisticated behavior that denotes the working of sophisticated brains. Consider three quick examples.
Compared with the hoofed animals of the veldt, hyenas are slow creatures. They can run at about 40 mph compared with 50 mph for a wildebeest. They have therefore learned to be clever team hunters. Often lions scavenge from hyenas rather than the other way around. The hyaena seems to decide upon the type of prey it wants in advance then uses appropriate tactics for that creature. David Attenborough tells us that they are happy to hunt wildebeest but will ignore them if they have decided that today’s dinner is to be zebra. Prairie dogs, communal animals that live in “towns” go in for horticulture. They cut down certain plants, not to eat—they do not like the taste of them—but to create more space for those they do like. Every now and then they leave a territory for no other reason than to let it lie fallow to recover, then they return to it. Finally Sea otters are intelligent enough to use a tool, such as a suitable pebble, to break shellfish from the rocks and to crack open their shells. All evolved since the death of the dinosaurs.
Yet surely the selective pressure on the mammals in the world of the dinosaurs would have been more favorable to the development of the mammalian neocortex. Intelligence is a weapon in the evolutionary arms race between predator and prey. The mammals were the oppressed animals, oppressed by the superior dinosaurs. Plainly, if the mammals were more intelligent than the dinosaurs then they should have been able to outwit them and usurp the dinosaur’s dominant status. They didn’t so they weren’t. The mammals, including the primates, could not capitalize on intelligence in the Cretaceous because there already were intelligent creatures around quite capable of holding their own against other dinosaurs let alone the pretensions of early primates or any other mammal. Just as mankind eliminated the intelligent opposition, the anthroposaurs would have eliminated any other animal, dinosaur or mammal, that seemed likely to become a rival.
What of the niche later occupied by the primates. Was it occupied in the Cretaceous by primosaurs, dinosaur equivalents of the primates, and only when they died was the mammalian version able to develop? If convergent evolution is anything to go by, perhaps the intelligent dinosaur had to descend, like the intelligent mammal, from the trees or, perhaps, emerge from the water.
What was in the trees when the dinosaurs were on the ground? From the fossil record there seem to be no dinosaurs adapted for tree dwelling in the sense that such creatures as monkeys, apes or even squirrels are today. Yet, if there were no dinosaurs in the trees, the mammals would have had a perfectly safe niche, would surely have evolved into it and, if they merely had to find a place free of dinosaurs to realize their destiny, developed brains much earlier.
Fossils of predatory dinosaurs are rare—Robert Bakker claims that he only came across a few fragments of them in six years of field work—but fossils of forest species are rarer. Fossil chimpanzees, from much closer times, are totally non-existent. We have only five fossil skeletons of Archaeopteryx which presumably spent some of its time in trees. Fossils of pterosaurs are mainly of marine species which swooped around the edges of the sea.
The problem with tree dwellers is that their dead bodies drop to the forest floor where they are most unlikely to leave a fossil record. The forest is rich in fungi and bacteria that thrive in the damp and the shade and the little that is not eaten by scavengers decays in a short time. And the bones?—the forest floor is acidic so that even the bones do not survive long enough to leave a trace. So there is no fossil evidence to suggest what was in the trees when dinosaurs roamed the ground.
Experts tell us that, since mammals, like tree shrews, were there, dinosaurs were not—otherwise trees would not have been safe for them. But, if the dinosaurs were afraid of heights, how did the pterosaurs and archaeopteryx learn to fly? It is absurd that dinosaurs should not have adapted to life in the trees and the pterosaurs and archaeopteryx prove it.
Lagosuchus, thought to be an ancestor of the pterodactyls, was a primitive dinosaur that must have climbed trees. Today, Komodo dragon hatchlings live in trees to avoid predators. Many other cold-blooded animals climb trees, the many species of tree frog for instance. Why should there not have been hosts of dinosaur monkeys and dinosaur apes? Perhaps there were but, as we have seen, because of their habitat they did not fossilize easily: a whole fauna of advanced dinosaurs about which we know nothing. Is it so stupid then to guess that one of them might have followed a pathway to intelligence just as we did?
There is a parallel between the explosive radiation of dinosaurian grazers like hadrosaurs and ceratopsians from the middle Cretaceous and the explosion of mammalian grazers about 11 million years ago.
The mid-Cretaceous explosion was a result of the breakthrough of the flowering plants about 117 million years ago just as the more recent case was due to the emergence of the grasses 24 million years ago. Along with the antelopes, horses, cows and elephants of the latter period, taking advantage of the new food stuff, came the intelligent mammal, man. Lucy walked by that East African lakeside just as cattle and horses were evolving 3.7 million years ago. Since then, man has continued to evolve rapidly, though the animals that originally shared the savannah with him, such as the antelopes, have not.
Can the parallel be extended? Did an intelligent dinosaur emerge from the Cretaceous forests, a part of the explosive radiation of dinosaurs resulting from the earlier emergence of the flowering plants as a new source of food, and, like man, evolve exceedingly rapidly? If an aquatic phase gave man many useful features during his development, is it possible that some dinosaurs lived aquatically for awhile and developed a comparable streamlined shape and upright stance as well as other useful features?
With the plucking of the hadrosaurs from the experts’ approved place in the swamps, to be placed in herds on mossy plains, there seemed to be no semi-aquatic dinosaurs remaining at the end of the Cretaceous. Animals such as the ichthyosaurs and the plesiosaurs, which the experts do not classify as dinosaurs, were fully aquatic, and the ichthyosaurs might have died out before then anyway. Yet, for 20 million years, sea-levels had been higher than at any time in the last 200 million years. There were vast areas of shallow continental seas. Surely a lot of species must have dipped their toes in the water and some of them must have tarried awhile.
Lots of shallow seas imply lots of small, perhaps transient, islands ideal for evolutionary experiments like those described by Elaine Morgan—but 65 million years earlier. Suggestive also is Bakker’s idea that the archaeopteryx was possibly able to use its primitive wings to swim rather as a hoatzin fledgling does. Both archaeopteryx and deinonychus had wrists with a semicircular joint which permitted accurate movement of the fingers and exceptional ability to flex them. It is conceivable that, while the archaeopteryx was evolving into birds that some other members of the family turned to brachiating and developed along the lines of first the modern primates, and then the aquatic ape, to yield Anthroposaurus sapiens.
Gribbon and Cherfas attribute the growth of intelligence in man to the succession of ice ages over the last few million years. This sequence of glacials and interglacials subjected the hominid apes to repeated intense selective pressure putting a premium on adaptability, versatility and intelligence. Though there were no ice ages at the end of the Cretaceous period, we noted that the sea level was high. It fell considerably and quickly 95 million years ago and again 67 million years ago, but over several million years, about 80 million years ago, there was a shallower dip. With large amounts of the continental shelves covered in water, fluctuations of only a few meters could successively expose then inundate large areas of land.
The normal tidal range today can make the sea disappear over the horizon at low tide in those places where the beach shelves at only a slight angle. The slow shallow dip observed in the sea level when it was at its height possibly signifies thousands of such incursions of the ocean. Imagine a Spring tide that went out for ten thousand years before it returned. Then it stayed in for ten thousand years. This would put strong selection pressure on the species living on the flat coastal lowlands or on low islands.
Possible confirmation is the formation of oil bearing rocks at that time. Half of our present oil reserves stem from that period, the result of organic matter settling to the bottom of shallow stagnant seas. Incursions of the ocean would have trapped the organic layers between thin layers of mud eventually giving rise to oil shales from which oil was squeezed under pressure.
Further evidence of such cycles comes from the striated appearance of Cretaceous chalk cliffs. Is it possible that fluctuations in sea level provided the evolutionary stimulus for the anthroposaurs that Gribbon and Cherfas argue was provided by ice ages in the evolution of mankind? Did the same fluctuations force a brachiating dromaeosaur to turn to the water temporarily, giving it a range of advantages just as Morgan argues for mankind’s predecessor?
“A final mystery looms large in the story of [dinosaur] predator and prey”, Robert Bakker tells us. It is that, unlike the ankylosaurs and the ceratopsians, the hadrosaurs had no obvious means of defence against ferocious predators like the tyrannosaurs. They “had no whiplike tails, long claws, or any type of spike or plate. And their limbs were shorter and designed for lower top speeds than were those of their gracefully long-legged hunters. How did these normally slow moving, unarmed browsers escape their enemies”?
An intriguing question.
Obviously the various weapons of the other creatures were advantageous or they would not have evolved. Why then did the hadrosaurs not need them? Orthodoxy has it that they were caring parents and apparently moved about in herds, traits that could have given them sufficient advantage. Their strong social sense and protective instinct would have allowed them to proliferate into immense herds wandering the continents. There is safety in numbers as we see on what remains of the African veldt. Perhaps they just sacrificed the old, the infirm and the weak for the benefit of the rest.
Hadrosaurs showed explosive diversification shortly after descending from the iguanodonts towards the end of the Cretaceous. Extreme diversification depends on genetic variation. The greater the extremes, the more variation is implied and vice versa. Dinosaur extremes indicated great genetic variation which accounted for their ability to adapt and to radiate into vacated niches.
The reason they could not cope with the events of 65 million years ago whereas they had successively coped splendidly with previous mass extinctions, the so-called Kimmeridgian turnover of 145 million years ago, the Aptian turnover of 117 million years ago and the Cenomanian turnover of 95 million years ago, was that in the few million years before the final act they had lost variation and had become inflexibly standardized.
The last few million years of the Cretaceous showed a marked reduction in diversity of dinosaur species: the earlier vigorous adaptive radiation of the hadrosaurs and the ceratopsians similarly gave way to a yielding of variety. For the last two million years of the Period, a single genus of each—saurolophus and triceratops respectively—dominated the landscape, although they did so in vast numbers.
No gradual environmental change is going to eliminate genetic variation in genus after genus of dinosaurs. That very variation will guarantee adaptation to the changes by natural selection before genetic variation has been significantly pruned. The motive power of evolution is expansion of diversity with environmental change. The dinosaurs’ loss of variety is much more characteristic of the loss of variety in species we are seeing today—by unnatural selection—at the hand of man.
Caches of bones of a single species are regarded by paleoanthropologists as suggesting husbandry. In the development of man, various cultures seemed to concentrate on ibex, horses, reindeer and so on. Could it be that ceratopsians and hadrosaurs were actually domestic animals like cows and sheep kept for food?
Is it possible that hadrosaurs were the cattle of the Cretaceous period, herded on the great plains before being shipped to a Cretaceous Chicago for making into meat pies and hamburgers? Is it impossible?
