Marine mammals suddenly appear in the fossil record as whales, dolphins, sea cows, etc. For example, in one of Romer’s concluding statements in his discussions on subungulates (elephants, sea cows, etc.), he says: “The proboscideans and sirenians are already different groups at the time they first appear in the fossil record.” Olson claims that if we seek the ancestors of marine mammals, we encounter a blank wall as long as the transitional stages between land and sea. This comment included seals, dolphins, and whales. There are simply no transitional forms in the fossil record between marine mammals and their supposed terrestrial mammalian ancestors.
Romer suggests that whales originated from a primitive mesozoic mammal, though in regard to Sirenia (sea cows) and Cetacea (whales, dolphins), he allows that: “We do not know their terrestrial origin and cannot be certain of their place of origin.” It is interesting to note that many so-called “primitive” mammals of the mesozoic had 40 teeth differentiated into incisors, canines, premolars, and molars. Marine pigs, dolphins, and whales, however, can have much more than that number (the sea pig has 300), and the teeth of these marine mammals are usually simple cones or wedges and are not divided into incisors, canines, premolars, and molars.
Würsig recently suggested that dolphins might have evolved from land mammals resembling today’s even-toed ungulates such as cows, pigs, and buffalo. It is quite absurd, starting with cows, pigs, or buffalo, to imagine what the intermediaries might have looked like.
The recent claim that a transitional form between land mammals and whales has been found was published in newspapers and magazine articles around the world. For example, an article by the Associated Press from April 15, 1983, appeared in the Detroit Free Press under the title ‘Missing Links in Fossils Connect Whales to Land Mammals.’ In this article, it is stated that scientists discovered 50 million-year-old fossils of a 2-meter-long land creature which they described as the ‘missing link’ between whales and land animals. This article continues with the claim that the fossil remains represent the oldest and most primitive form of whale ever discovered – an amphibious mammal that lived and reproduced on land, but fed in shallow seas. One should immediately be suspicious of the term ‘whale’ applied to such a creature, whatever it may have been, given that whales are totally incapable of life and reproduction on land.
News of this kind, vague and unreliable as they may be, are undoubtedly welcomed by evolutionists since they indeed, as is the case with all other mammalian orders, represent a large gap between the order Cetacea (this order includes all creatures encompassed as ‘whales’ – whales, dolphins, and porpoises) and any supposed pre-whale creatures. Speaking of whales, Colbert says:
‘These mammals must have had a very ancient origin, since intermediary forms are absent in the fossil record between whales and pre-whale Cretaceous placentals. Like bats, whales (using this term in a general and concluding sense) appear suddenly in the early Tertiary, fully adapted by deep modifications of the basic mammalian structure for a highly specialized way of life. Indeed, whales are even more isolated compared to other mammals than bats; they stand completely alone.’
But what about the material upon which the newspaper articles are based? Can this material reasonably be interpreted as whale-like? The articles are based on interviews with Dr. Philip Gingerich from the University of Michigan and on a paper published by Gingerich, Wells, Russell, and Shah in the journal Science. This fossil material consists of the back part of the skull, two fragments of the lower jaw, and isolated upper and lower cheek teeth. The creature supposedly represented by this material, named Pakicetus inachus (it cannot, of course, ever be certain that the scattered fossil material all belongs to the same species).
This fossil material was found in fluvial red sediments, or river deposits colored by material soaked in iron ore. This formation thus represents a terrestrial or continental deposit. Fossil remains associated with Pakicetus dominate among land mammals. Non-cetacean remains include other terrestrial remains similar to those of snails, fish (especially marine spiders), turtles, and crocodiles. This evidence points more to a fluvial and continental environment, rather than a marine one, as would be expected for whales or cetacean creatures.
The authors claim that the base of the skull (only the back part of the skull was found) undoubtedly belongs to a primitive whale. Based on the brief description given in this article (eight lines of text), there is no way to know if it is accurate, except through the authors’ statement. However, it seems very significant in this sense that the auditory mechanism of Pakicetus was more similar to a land mammal than to a whale, since there is no evidence that it could hear directly underwater, nor is there evidence of vascularization of the middle ear to maintain pressure during diving.
The teeth of Pakicetus, according to the authors, resemble those of terrestrial mesonychids of Condylarthra and are also similar to the teeth of mid-oceanic archaeocetaceous Cetacea such as Protocetus and Indocetus. Mesonychids are believed to be land mammals that had hooves and fed on carrion, mollusks, or tough plant material. The authors mention two other “primitive whales,” Gandakasia and Ichthyolestes, known only by their teeth, which were found in the same formation as Pakicetus. These were described by West and had previously been identified as land mammals (especially mesonychids). However, West assigns them to the order Cetacea.
No fragment of the postcranial skeleton of these creatures was found, so we have no idea what they actually looked like. The fact that their remains were found in a terrestrial fluvial deposit with fossils of many other land animals, that their teeth were very similar to those of known land animals, and that their auditory mechanism was obviously not like that of a whale, seems to indicate, at least, that the claim that the missing link between whales and land mammals has been found is very premature. We recall the statement by Professor Derek Ager (not a friend of creationists) that every evolutionary story he learned as a student is now outdated. We assume that Pakicetus will eventually join the ranks of the outdated “missing links.”
- Literatura
- Ref 1. A. S. Romer, Vertebrate Paleontology, 3rd ed. , U. of Chicago Press, Chicago, 1966.
- Ref 2. E. C. Olson, The Evolution of Life, The New American Library, New York, 1965.
- 1. Romer, Ref. 1, str. 254.
- 2. Olson, Ref. 2, str. 178.
- 3. Romer, Ref. 1, str. 279.
- 4. Romer, Ref. 1, str. 339.
- 5. B. Wursig, Sci. Amer. 240(3):136(1979).
- 6. E. H. Colbert, Evolution of the Vertebrates, John Wiley and Sons, New York, 1955, str. 303.
- 7. P. D. Gingerich, N. A. Wells, D. E. Russel and S. M. I. Shah, Science 220:403 (1983)
- 8. Romer, Ref. 1, str. 244.
- 9. R. M. West, J. Paleont. 54:508 (1980).
- 10. D. V. Ager, Proc. Geol. Assoc. (Britain) 87:132 (1976).