by: Rick Johnson 
PO Box 40451
Tucson, Az.
85717
RikJohnson@juno.com
Return to the Home Page.
Return to the Pal-ul-Don Page
Using North America during the Mesozoic era as an example we find that as the inland seas invaded the plains, the number of different species of dinosaur dropped due to the limited land area. As the seas receded and the land area increased, the species of dinosaurs expanded into new niches and diverged to create newer varieties of dinosaurs. Then as the seas returned, the area reduced and so did the number and variety of species
When we compare this to Pal-ul-Don we see a similar situation… Pal-ul-Don was once a part of Africa which retained a very few dinosaurs (we call them living fossils) that had become extinct elsewhere. Then as the water level raised, swamps formed and Pal-ul-Don became isolated and the local fauna began to adapt to the new conditions and evolve along a different line. The Lion became the Ja, the Smilodon(?) became the Jato, the remaining Triceratops became the Gryf and the isolated humans became the D’don.
Considering that Pal-ul-Don compromises a rough oval 70 miles north-south by 50 miles east-west, this 3500 square miles encompasses an area the size of Cyprus or Puerto Rico. This gives an extremely small area which will result in a small number of species and a limited number of individuals that would tend to encourage benevolent mutations to pass throughout the population rapidly via inbreeding, eliminating those without the mutation.
The primary predators in this area are now the Gryf, the Jato and the Ja with a Swamp Saurian in the surrounding marshes.
The Gryf is the top-of-the-pyramid predator. Omnivorous but primarily herbivorous (otherwise the Gryf would quickly eliminate all other animals), the Gryf is descended from the Cretatious Triceratops of the plains and once in the Pal-ul-Don forests, the Triceratops adapted to the newer forest environment by growing larger (as did the Coelacanth when it moved from shallow fresh water to the deep salt ocean) and changing it’s diet to include all possible food sources.
Fortunately the Gryf is long lived (having no natural predators once hatched) and so has very low numbers.
The Ja is descended from the common forest lion and so is solitary and has retained the spots of it’s youth to better hide as it hunts in the newer environment.
The lions that we know are the Veldt Lion which lives in the open grasslands and encompasses a Pride composed of an adult male, his female mates and their immature children.
The Forest Lion of ERB is solitary and thus much more dangerous than the Veldt version.
The Jato is described as a ‘saber-tooth hybrid’ between the saber-tooth tiger and the lion but in nature the Smilodon wasn’t a tiger but a long toothed, short tailed feline. However, saber-teeth have evolved a number of times over the life of nature in a number of widely unrelated animals so it is possible that the Jato is really an offshoot of the Forest Lion or Leopard that simply evolved long canines and an overly aggressive attitude.
Tigers and lions can interbreed occasionally (mostly in captivity) but the results are often sterile mules.
ERB describes no other predators and in an area that small, there may very well be none.
Herbivores must outnumber predators by a ratio of about 10 to 1 although the number of separate species need not be this large.
Africa contains zebra, antelope, deer, wildebeest and many other herd animals though ERB describes only deer inside Pal-ul-Don. I would suggest that as Tarzan mentioned that a person who couldn’t eat in Pal-ul-Don would starve in a supermarket, there must be a variety of herbivores to fill the niches of forest, plains and mountains grazers and browsers. Therefore I postulate goats, antelope and possibly giraffe (the Gryf filling the eco-niche of the elephant).
As the Gryf and possibly the Jato are the only known living-fossils, I submit that most of the remaining Pal-ul-Donian animals are modern forms diverging since the isolation which may exclude the Zebra as a too recently evolved beast. Thus the idea of T-Rex and other such dinosaurs would be unlikely.
The same would be true with large flightless carnivorous birds such as the Phororachus. Although such birds evolved often, they always did so in isolated areas and were quickly exterminated by mammalian predators at the earliest opportunity. The big cats did so to the Phororachus in South America as did humans in New Zealand. In fact, the only large flightless bird still living is the Ostrich which, somehow, defies extermination. I believe that ERB would have mentioned a large bird had one been there.
As for flying birds themselves, not being held back by the swamp barrier, birds, bats and other flying animals would easily pass as they wished and so the birds of Pal-ul-Don would be no different from any other bird found in Central Africa. No giant eagles, no Pterosaurs, no winged humanoids.
Creatures of the water would include those that could easily pass the swamp barrier and so would resemble their outer forms. These would be large Monitors, Crocodilians, snakes and such. The one exception would be the so-called Swamp Saurian which could be a variety of crocodile or, more likely, a form of monitor lizard that resembles the pliosaur. Monitors, a species that includes the Komodo Dragon, often find humans to be on their menu and are at home both in and out of water.
There would be many varieties of fish, amphibians and reptiles such as snakes, turtles, tortoises in and around the lakes and rivers though the fact that both Jane and Obergatz managed to survive a solitary existence implies that few are dangerous to humans.
In the mountains would be bats, birds and probably goats of some sort though sheep are unknown due to the known lack of cloth.
As insects would have no trouble crossing the swamp barrier, these also would be similar to their outer forms and would include normal grasshoppers, beetles, moths & butterflies, dragonflies, mosquitoes and so on.
The idea of gigantic ticks and dragonflies with two-foot wings wouldn’t exist as 1) all fossils of insects that preyed on dinosaurs are of modern size, 2) the square cube law and the specifics of insect respiration prevent gigantic insects from existing and 3) if such forms existed, they could easily pass the swamp barrier and infest the outer areas of Africa.
The square-cube law states that if you double the size of an animal, it becomes twice as strong but four times as heavy. Double it again and it is 4 times as strong but eight times as heavy and so on until it is simply too large to move.
To understand this, consider a 150 pound man who is an athlete as compared to a 300 pound man who can never be athletic and can barely move his own bulk. The same exists with insects and animals. The tarantula is about as big as they can come and the elephant is so large that it cannot run and will break it’s legs if it steps off a curb without care.
Now we come to humanoids.
Burroughs describes the inhabitants as being “pithecanthropus” but also describes them as being handsome according to European values, an obvious contradiction.
As Pithecanthropus (Java Man) had a skull that barely rose above his eyebrows and a brain a little more than half the capacity of modern man, it is difficult to understand how ERB could consider this person to be anything resembling “handsome”. It is probable that ERB misunderstood Tarzan’s description of the D’don.
Therefore I submit that the D’don (Homo Sapiens Arborilis) is a form of modern man (Homo Sapiens Sapiens) that simply adapted to an arboreal environment and any mutations that enhanced this tree-life would be passed on and encouraged in a small, isolated and inbred population.
The D’don then quickly diverged into the white hairless (Ho-Don) and the black hairy (Waz-Don) forms. As the Waz have straight hair, it is unlikely that they developed from the Negroid race which evolved much more recently than the other races. Rather both forms probably evolved from single ancestor from north Africa (same probable stock as the Sudanese and Egyptian) and after the arboreal mutation took hold, they branched into the darker-skinned and straight haired Waz and the lighter skinned and rarely hairless Ho forms.
This doesn’t, however, explain the Tor version of the D’don.
The Tor-o-don is larger and stronger than the Ho or Waz races but not as intelligent even though the Tor appears to use tools and tame the Gryf and so may possess language. It would be interesting to know if the Tor-o-don speaks the common language of the outer-world primates (mangani) or a version of the D’don language with seems to be related or descended from Mangani.
I refer to the common language of the Mangani, Bolgani, Manu, Tongani and even the Pellucidar Sagoth as “Mangani” in much the same way as we refer to the language of the people of England as English.
The language of Pal-ul-Don would then be referred to as Donian or D’donian or possibly Donish.
Another question is did the Tor branch off from the ancestral race after the arboreal mutation occur or is the Tor form a version of the Mangani that evolved an arboreal form because of convergent evolution? I favor the former theory for it’s simplicity and postulate a form of Homo Sapiens from North Africa migrating south and becoming isolated in pal-ul-Don as the swamps developed. These isolated humans developed an arboreal mutation which spread via inbreeding of a far too small population and when the arboreal form was fully developed, this Homo Sapiens Arborilis then branched into the intelligent human form and the physical Tor form. The human form then branched into the Ho and Waz forms.
This, then would be the evolutionary biology of the animals life of Pal-ul-don.
To contact me or to request topics to be covered, send to RikJohnson@juno.com
by: Rick Johnson
PO Box 40451
Tucson, Az.
85717
Return to the Home Page.
Return to the Pal-ul-Don Page
