Ichnofossils, or trace fossils, are fossils other than the remains of the actual organism (such as bones). Ichnofossils, also called Ichnites, include the tracks or burrows of organisms. In July of 2017, geologist Gerard D. Gierlinski and his colleagues announced in the Proceedings of the Geologists’ Association the discovery of some interesting ichnites on the Greek island of Crete. These ichnites were footprints. The main surface with identifiable footprints (B2) was found at a site near the village of Trachilos, which is located at the northwestern tip of Crete. The sediments containing the footprints were solidified calcareous (chalky) sands. The researchers said (p. 5), “We interpret surface B2 as representing an area of aerially exposed sand close to the shoreline, possibly part of a small river delta.” According to the researchers, the solidified sands were about 5.7 million years old. This means they are from the latter part of the geological period called the Miocene, which extends from 5.3 to 23 million years ago. At 5.7 million years ago, according to the researchers (p. 12), Crete was connected to southern Greece by a land bridge.
The researchers (p. 6) pointed out features that indicated the impressions they found were made by a foot pressing into soft sediments and were not just natural features that resembled footprints: “The quality of track preservation is variable, but the best specimens have clear displacement rims (expulsion rims) and sharply defined edges.” The researchers (p. 6) concluded that the Trachilos track makers were bipedal because of the absence of any forelimb prints. Bipedal creatures walk with upright posture, on two legs.
The footprints had many features like those of human feet. The researchers, using technical language, said (p. 8), “The Trachilos tracks appear to have been made by a bipedal trackmaker with plantigrade, entaxonic, five-toed feet that did not leave claw impressions. The first digit of the foot was bulbous whereas digits II–V were slender, with no significant gap between the hallux and digit II. A well-developed ball was present.” Humans like us are bipedal—we walk upright on two legs. We humans are also plantigrade. We walk with the whole surface of the foot touching the ground. Digitigrade animals, such as dogs, walk on their toes, with the rest of the foot elevated. Unguligrade animals, such as horses, walk on their modified nails (hooves). We humans are also entaxonic—having the inner, or first, digit (e.g., big toe or hallux) more strongly developed than the outer digits. Furthermore, our hallux, or big toe, is in line with the other toes, not angled to the side. Finally, we do not have claws. As for the size of the prints, the researchers said (p. 5), “The ichnites that can most readily be identified as footprints range in size from 94 to 223 mm.” That would be 3.7 inches to 8.8 inches. The larger prints (8.8 inches) are at the smaller end of the size range of the adult human foot. This suggests that the smaller Trachilos prints were not those of adults.
The researchers took great care to distinguish the Trachilos prints from the footprints of animals that might resemble human footprints. The two kinds of animals with footprints most closely resembling human footprints are the bears and apes, both which sometimes walk bipedally. The researchers (p. 8) pointed out that bear footprints “are rarely entaxonic, and certainly never to the degree exhibited by the Trachilos prints; the carnivore hallux is not morphologically distinctive and is at most marginally bigger than adjacent digits.” In other words, bears did not make the Trachilos footprints. As for the apes, the researchers said (p. 8) they “have strongly divergent thumb-like halluces [big toes], always set back from the relatively long lateral digits. Chimpanzees produce characteristic L-shaped footprints with a wide gap between the hallux and curled lateral digits.” They added (p. 8) that ape prints “typically lack a ball impression.” The Trachilos prints, like those of modern humans, displayed distinct ball impressions (p. 8).
However, the researchers thought that the Trachilos prints were in some ways different than those made by the feet of modern humans. These alleged differences were confined to the rear part of the foot. They said (p. 8) the Trachilos footprints did not display an arch in the foot. But many humans do not have a foot arch. They have flat feet. According to the Institute for Preventive Foot Health, “Flat feet (pes planus) is a fairly common condition in which the foot does not have a normal arch, and so the entire foot touches the floor when you’re standing. According to the 2012 National Foot Health Assessment conducted by the NPD Group for the Institute for Preventive Foot Health, 8 percent of U.S. adults ages 21 and older (about 18 million people) have the condition” (https://www.ipfh.org/foot-conditions/foot-conditions-a-z/flat-feet). Another factor is the variable nature of footprints, the forms of which depend on many factors, such as the consistency of the sediment. The researchers themselves said (p. 1), “The variables at play here are complex and a single trackmaker may produce a range of tracks.” Even if the foot had an arch, some of the prints might show an arch, and some might not.
The researchers (p. 8) also said the Trachilos footprints had a narrow, rather than bulbous, heel. But the Institute for Preventive Foot Health informs us that narrow heels frequently occur in the feet of women. The Institute says that “women’s feet taper more dramatically from forefoot to rear foot than do men’s (i.e., they are more narrow in proportion to the forefoot… Men also can have feet with heels that are narrow relative to their forefoot size; although this is less common, it still poses problems for shoe selection and fitting for some men” (https://www.ipfh.org/foot-conditions/foot-conditions-a-z/narrow-heels/). Furthermore, the Trachilos researchers (p. 8) themselves admitted, “In a few prints the heel impression appears bulbous rather than narrow.”
Altogether it appears that the Trachilos footprints are very much like modern human footprints. Of course, according to the currently dominant ideas in science, humans like us did not exist 5.7 million years ago. Most scientists believe humans like us first appeared between two and three hundred thousand years ago. So the researchers (pp. 9-11) attributed the Trachilos footprints to either: 1) a currently unknown early hominin-like species; or 2) one of the hominin species known to have existed in the late Miocene, between 5 and 7 million years ago, in Africa and Europe. (According to modern evolutionary science, hominins are the group of primate species that include humans and the direct ancestors of humans.)
The researchers (p. 11) seemed to prefer the second option—that the Trachilos track maker was one the recognized Miocene hominins. But this was not so easy to justify. While the researchers were writing their report on the Trachilos prints, other researchers identified as a hominin a creature called Graecopithecus, known from fragmentary skeletal remains in Greece and Bulgaria. Graecopithecus existed about 7.2 million years ago in the late Miocene (p. 10). But Gierlinski and his colleagues (p. 10) could not positively identify Graecopithecus as the Trachilos track maker because there was no fossil evidence for the Graecopithecus foot.
The hominin species that existed in Africa during the late Miocene were Orrorin tungenensis, a small hominin that existed between 5.7 and 6 million years ago, and Sahelanthropus tchadensis, another small hominin that existed about 7 million years ago. But just as in the case of Graecopithecus the researchers (p. 10) pointed out a problem with this option: “Virtually nothing is known about the foot morphology of the Miocene African hominins and no hominin trackways of this age are yet known from Africa.” In other words, the foot structure of the African Miocene hominins is unknown. Therefore it is not possible to attribute the Trachilos footprints to Orrorin or Sahelanthropus with any degree of certainty. Their feet were most probably apelike. Supporting this inference is the fact that the foot of a later hominin, Ardipithecus ramidus, did not have the humanlike features of the footprint of the Trachilos track maker. The researchers said (p. 9), “Interestingly, the non-divergent hallux [big toe] and short lateral digits of the Trachilos tracks are absent in the foot skeleton of Ardipithecus ramidus known from Ethiopia, which is more than a million years younger.” In other words, Ardipithecus had a divergent big toe that extended out to the side, and its other toes were quite long. Actually, the only creature, which is known to science from skeletal evidence, which has a foot displaying the characteristics of the Trachilos footprints is Homo sapiens.
In their conclusion, the researchers (p. 13) said, “Despite the fact that the full 3D anatomy of these tracks is not optimally preserved, they are not poor trace fossils. Their outlines are particularly clear and form the basis of the morphometric analysis presented here. Better and more numerous trace fossils are always to be desired, but equally one cannot ignore the currently available evidence and their potential implications, however challenging they may be.” In my opinion, we should not ignore a potential implication—a very challenging one—that was not considered by Gierlinski and his colleagues, namely that the Trachilos footprints provide evidence for humans like us existing 5.7 million years ago.
CAPTION: Three-dimensional structure of a print. Left, laser scan of one of the best-preserved footprints. Right, transverse sections showing concave and convex structures. G.D. Gierlinski, et al: Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete? (Proceedings of the Geologists’ Association (2017), http://dx.doi.org/10.1016/j.pgeola.2017.07.006)
Michael A. Cremo is the author, with Richard Thompson, of the underground classic, Forbidden Archeology: The Hidden History of Human Race. He has also written Human Devolution: A Vedic Alternative to Darwin’s Theory. (Visit HumanDevolution.com).