The fish form of the CETACEA is not surprising at all for animals which swim all their life in the ocean. In some way,
it is even convenient for the taxonomist, because the ancestors of the CETACEA might have evolved from any branch
of the anterior Mammals up to their today hydrodynamic shape and configuration...
Simple suspension in the water, without moving, has already been put into effect by a spherical form of the body, like in
jellyfishes or in some algae.
As the oceanic creature tries to move, the things become a lot more complicated... The animal’s body is now thrusted
against the water surface, through the action of the Archimede’s forces !
So, if the creature really attempts to keep itself steadily sunk in the water, then it must actively fight against the natural
tendency of its body to ascend and to break surface : otherwise, the animal only floats !
The anatomical structure of the whales, in the same way as the corresponding structures in a fish or in an ichthyosaur,
are obliged to yield to the needs of a straight horizontal locomotion through the aquatic milieu. With one big difference between
fish and CETACEA with the latter, the flipper-tail knocks up and down, while the fish-tail curves
only laterally in the water.
According to this, there is thus a merely superficial resemblance of the CETACEA to the fish, surely best
pronounced in the external form of the head...
The CETACEA neck is short or not distinguishable ( the 7 neck vertebrae are short or are fusing in
one another : they are not freely movable like in other mammals ). The extremity of the snout is not
necessarily sharp-pointed, rather somewhat well-rounded ( like in fish ), for the best possible "high speed"
penetration through the water. In whales and dolphins, moreover, the flattened and compressed head also serves to reverse the
upward or downward progression.
Since, this peculiar character of a smooth-truncated head in whales, correlated with the flattening of the whole rostrum
and with the strong development of the trunk musculature ( in order to allow the "dolphin"swim ), leads us to think
that these are indeed among primordial features in the CETACEA ancestry !
In such a sense, the antecedents of the whales could not, for instance, have been in possession of a large,
sharp-pointed snout, as suggested ( fig. 1 ) by the reconstitutions of Basilosaurus cetoides
or of Ambulocetus natans.
The character of a "pointed" snout, resembling the snout of a crocodile, with nostrils at the tip, is rather a
phylogenetically derived feature, as also suggested by stages of the foetal development in the whales.
Similitudes in the fossils and in the modern representatives of the CETACEA groups,
are surely found in the shape and function of the auditory bones, in the dentition or in the development of mighty jaws,
regarding the manners to retain a prey with their teeth and to gobble it up without masticating... Furthermore, some
whales developed specific structures like the whalebone sieve.
In that sense that they do not masticate, the CETACEA resemble more the dinosaurs
( or water reptiles like the crocodiles, the plesiosaur or the ichthyosaur ) than the other mammals.
In my opinion, a fossil like the Ambulocetus, recently found in Pakistan by
Hans THEWISSEN of the Northeastern Ohio College of Medicine and his team, is neither related to the
ARCHEOCETI ( allegedly thought to be the ancestors of the whales ) nor to the PINNIPEDIA
( otaries and seals ) that are connected with the plantigrade bears and with the originally bipedal mammals...
I would propose a special taxon, AMBULOCETI, for the genus Ambulocetus, with the
characteristics of a quadrupedal big-footed amphibious creature, probably originated from some undifferenced
CREODONTA ( see the tabloid on fig. 4 ). Ambulocetus used to catch its prey in diving
with the help of its strong hind legs. He also used flexion-extension ( in a vertical plane ) of its back
musculature to progress among the surface, as seals and otaries also do. The tail had more of a rudder function.
Ambulocetus was tramping on flat-bottom seas and pools, walked on land in the art of
otaries by bending his webbed hands and feet outsidewards. The AMBULOCETI had certainly no particular
disposition to remain during all of his life in the water and even not to rush into the conquest of the ocean’s immensity by
transforming into whales...
The AMBULOCETI surely became extinct in the course of the Tertiary period, without leaving
PHYLOGENETICAL SCALE OF THE EVOLUTION OF BIG WATER MAMMALS
REFERRING to INITIAL BIPEDALISM and to DE SARRE 1993,
THE ABOVE TAXA DEVELOPED FROM THE ANCESTRAL WATER FORMS WITH AN ERECT BODY
POSTURE ( ERECTA ) - THEY EVOLVED
( on the right side of the tabloid ) INTO THE CETACEA THAT LOST THEIR HIND LEGS ( = APODY )
Particularities of the CETACEA
Before we come to speak of the caudal fin with its 2 horizontal flukes, let us consider some
other typical characteristics of the whales.
The auditory bones ( hammer, anvil and stirrup-bone ) are highly modified, the tympanics
are shell-like and loosely attached to the skull : these modifications are done to adapt in the conditions of audition
among the water surface. Similar adaptations may have occurred in other aquatic lineages and are a simple result
of convergence : they cannot be invoked in phylogenetical purposes, as the palaeontologists claim.
The nostrils ( = blow holes ) have been shifted in whales to the upper
side of the head, at some distance from the tip of the snout of beak. The blow holes are either 2 longitudinal slits
in the MYSTACOCETI ( whalebone whales ), or a single crescentic slit in the ODONTOCETI
( toothed whales ).
The nasal canals ( see fig. 2 ) pass nearly vertically downwards in front of a lofty
brain-case which is home the big globulous encephalon.
The larynx and epiglottis form a tube through the oesophagus, so the blow holes become
continuous with the windpipe and the lungs. The mouth is being used solely for feeding, as in newly born mammals, but
not in adults, which can breathe through either the nose or the mouth. In fact, this system is a particular feature of the
whales that indicates a very ancient adaptation to life in the water. It is not to be observed in the allegedly "prior" forms,
like the AMBULOCETI or the ARCHEOCETI.
The question of the caudal fin
The palaeontologists usually claim that the CETACEA developed during the Eocene period.
Their ancestors were allegedly quadrupedal land mammals. Through a transitional form that may have looked like a seal, then losing
legs and pelvis ( vestiges of which, as well as vestiges of femurs, are still embedded in the flesh of the baleens ),
they evolved into the typical whalebone ( MYSTACOCETI ) or toothed ( ODONTOCETI ) whales.
The problem is not only how the CETACEA obtained a big globulous brain from
antecedents that may have looked like Ambulocetus, but also how they develop their typical caudal fin ?
It must first be said that the "tail" ( as it is commonly called ) of the whales, is in reality
a sympodium attached to the extremity of it.
The tail is only the prolongation of the body vertebrae. The 2 horizontal flukes are boneless
fleshy appendices. They are supported in the middle by the tail.
As expressed by mammalogist Serge FRECHKOP in 1944, the lower skin surface of the
CETACEA flukes is homologous to our plantar foot surface !
Dr. FRECHKOP further remarks that the caudal fin of the CETACEA works in a similar
way like a motor-boat propeller, i.e. in a helicoidal motion, with the only restriction that the rotation is, evidently,
not complete !
This fact can surely be explained by the original disposition of their 2 legs and feet
( see fig. 3 ) before they began to disappear, as the specific tail muscles parallely developed...
Similar patterns are certainly due to explain the development of the caudal fm in the
SIRENIA and in the ARCHEOCETI, which kept a movable neck.
The horizontal disposition of the tail-flukes in the ancestors of the CETACEA did facilitate
the rising from or to the water surface, whereas the fore limbs were used for maintaining the body’s balance
and for steering. They contain the typical mammalian bones.
A fleshy dorsal fin for a better stabilization in water then appeared in the whales, as they became
the hydrodynamic fish form. Sometimes, the dorsal fin is wanting, as the rostrum is well-careened.
From the standpoint of the Theory of Initial Bipedalism, as emphasized by several authors
( Max WESTENHOFER, Serge FRECHKOP, Bernard HEUVELMANS ), the original mammals
were bipeds and they were closely connected with a prior aquatic phase.
In my Marine Homonculus Hypothesis, I suggested the vertebrate brain resulted of an
ancient apical organ that was conceived originally as a spherical float in a marine creature.
The characteristics of a big brain in a globular skull, and of the bipedal gait, were obtained before the
adaptation of the first mammals to a terrestrial way of life.
As a matter of fact, the skull of the CETACEA is being deeply transformed, consistently
with the external "fish" form. Therefore, the large and efficient encephalon has remained quite undamaged, not far different from
a human brain !
So I emphasize that the CETACEA directly evolved from the Marine Homonculus
stage. In other words, the whales and dolphins have always lived in the oceans !
Indeed, with the exception of the zoophagic feeding, the CETACEA show no characteristics
that would bring them in connection with the quadrupedal CARNIVORA or with the undifferenced ancestors of the today
In that sense, the relation with the newly discovered fossil Ambulocetus, enhanced
as "missing link" by the scientific press, appears as one of the usual and common blowers in the course of the development
of natural science...