Trachilos footprints

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Rock slab with the footprints

The Trachilos footprints are tetrapod footprints which show hominin-like characteristics from the late Miocene on the western Crete, close to the village of Trachilos, west of Kissamos, in the Chania Prefecture.[1] Researchers describe the tracks as representing at least one apparent hominin or an unknown primate. The stratum in which the footprints were found was dated to about 5.7 million years ago, which predates the previously earliest discovered hominin footprints by about two million years. The researchers of the tracks suggest that it may imply the possibility of hominin evolution outside of Africa, contrary to the current theory.[2]

Discovery[]

The tracks were originally discovered in 2002 on the island of Trachilos, near Crete, by Gerard D. Gierliński, from the Polish Research Institute in Warsaw.[3] In 2012, he received permission from the Greek government to research the area, returning to Trachilos with other researchers to explore the tracks in detail.[4][5] The researchers used methods such as laser scans and 3D imaging.[6]

Dates[]

The tracks were dated by using the underlying rock bed, predominantly sedimentary, and foraminifera.[1] The study explains, "The coastal rocks at Trachilos[,] lie within the Platanos Basin, and present a succession of shallow marine late Miocene carbonates and siliciclastics[...] At the top, this marine succession terminates abruptly in the coarse-grained terrigenous sedimentary rocks of the Hellenikon Group[.]"[1] The study continues, stating that the sedimentary rocks would have been created around 5.6 million years ago, at the time of the Messinian salinity crisis (mya).[1] The researchers also found evidence of foraminifera, which were dated at 8.5 mya and 3.5 mya.[1] Given the date of the sedimentary rocks and the foraminifera samples, the researches created an approximate interval of 8.5 mya to 5.6 mya.[1] As the rock sediment containing the tracks resembled that of Hellenikon minerals, the tracks were estimated to be 5.7 mya within the given interval.[1]

In 2021, further research was published in regard to dating by Kirscher et al. Cyclostratigraphic data based on magnetic susceptibility indicated that the Trachilos footprints are about 6.05 Ma old, which is 350,000 years older than was found previously.[7] This puts the Trachilos footprints in the same period as the fossils of Orrorin tugenensis from Kenya.

Characteristics[]

The footprints were measured to be 94 mm (millimeters) to 223 mm long and determined to be oriented in a south-west direction.[1] There are clear pressure indexes, resembling that of a modern homo sapien plantigrade structure.[1] The researchers also determined the presence of five digits in the imprints, classifying the track maker as pentadactyl, and lacking claws.[1] As there was no visible evidence of forelimbs from the tracks, the track maker was identified as bipedal.[1] Through 3-D printing and laser scanning, there are impressions found which indicate a ball region, a pulling up motion of the foot, a hallux, and small possible gaps between the first and other digit impressions.[1] Poorly preserved prints lack these gaps however.[1] The lateral digit impressions become progressively smaller so that the digital region as a whole is strongly asymmetrical.[1] The impression of the hallux has a narrow neck and bulbous asymmetrical distal pad, indicating that the tracks were entaxonic.[1] Morphometric analysis showed the footprints to have outlines that are distinct from modern non-hominin primates and resemble those of hominins.[1]

While younger than fossil records of hominins such as Sahelanthropus, found in Chad and dated around seven million years ago, the discovery potentially challenges the generally accepted theory that all early hominins were only present in Africa.[1][2] The print morphology suggests that the trackmaker could be a basal member of the clade Hominini, but as Crete is some distance outside the known geographical range of pre-Pleistocene hominins,[1] researchers say that there is also a possibility that they represent a hitherto unknown late Miocene primate that convergently evolved human-like foot anatomy.[1]

News and controversy[]

When Gierliński and his team tried to publish the study, they received harsh criticism due to the findings going against the widely-accepted theory of early hominins evolving in Africa alone. According to the study, the Trachilos footprints may represent an early hominin or primate species that may have evolved hominin-like feet independently, outside of Africa.[1] It also suggests the possibility of convergent evolution, wherein unrelated species adapt similar traits and characteristics to each other. [1] [8] However, the theory is not well supported in this case, as there is no concrete evidence to suggest the theory results in perfect copies of traits or a whole species. As convergent evolution is not scientifically supported, there were doubts if the tracks were footprints at all.[5] This resulted in rejections from many scientific journals when offered to publish the study's findings.

In an interview at the CBC News, researchers claimed that while they were trying to publish their work about the footprints at high-profile publications they got "ferociously aggressive responses", criticism and rejection from reviewers and editors. According to the researchers “Basically, it wasn't a true peer review process at all,” “They were just trying to shut us down.”[5] After multiple rejections from other publications, the study was eventually published in the journal, "Proceedings of the Geologists' Association."[5][1]

Shortly after the research about the footprints was published, eight prints were chiselled out of the rock and stolen.[9] According to Protothema.gr, the culprit was a high school teacher, who was later arrested by Crete authorities at Kasteli, Chania.[9][5] The prints were later found in his house and on a farm.

David Begun, a paleoanthropologist at the University of Toronto, Canada, argues that the footprints might not necessarily belong to a human ancestor, despite its appearance. In a similar manner, Robin Crompton, a biological anthropologist at the University of Liverpool, England, believes that although the footprints belong to a bipedal organism, they might not be human ancestors but “made by a member of the great ape clad”. Multiple fossilized footprints must be found and analyzed in order to accurately categorize the tracks by species.[4]

See also[]

References[]

  1. ^ a b c d e f g h i j k l m n o p q r s t u v Gierliński, Gerard D. (October 2017). "Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?". Proceedings of the Geologists' Association. 128: 697–710 – via Science Direct.
  2. ^ a b G. D. Gierlinski, et al. Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?. Proc. Geol. Assoc (2017), https://dx.doi.org/10.1016/j.pgeola.2017.07.006 Available from: https://www.researchgate.net/publication/319411867_Possible_hominin_footprints_from_the_late_Miocene_c_57_Ma_of_Crete [accessed Sep 11, 2017].
  3. ^ “Footprints Hint That Humans Are from Europe.” New Scientist., vol. 235, no. 3142, 2017, p. 9., https://doi.org/10.1016/S0262-4079(17)31747-5.
  4. ^ a b Caperton Morton, Mary (December 11, 2017). "Mysterious Miocene bipedal footprints found in Crete". Earth Magazine.
  5. ^ a b c d e Chung, Emily (February 23, 2018). "One Hell of an Impression". CBC news.
  6. ^ "Mysterious Miocene bipedal footprints found in Crete".
  7. ^ Kirscher, U., El Atfy, H., Gärtner, A. et al, Age constraints for the Trachilos footprints from Crete. Sci Rep 11, 19427 (2021). https://doi.org/10.1038/s41598-021-98618-0
  8. ^ Kirk, John Thomas Osmond (2007). Science & Certainty. Csiro Publishing. pp. pg. 79. ISBN 978-0-643-09391-1.
  9. ^ a b "Local High School Teacher Arrested for Fossil Footprints Theft in Crete". themanews.com.{{cite web}}: CS1 maint: url-status (link)
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