Rising Star Cave Explained

Rising Star Cave
Map:Africa#South Africa#South Africa Gauteng
Relief:yes
Location:Near Krugersdorp in the West Rand municipality of Gauteng province, South Africa
Entrance Count:Many
Hazards:narrow access

The Rising Star cave system (also known as Westminster or Empire cave) is located in theMalmani dolomites, in Bloubank River valley, about 800meters southwest of Swartkrans, part of the Cradle of Humankind World Heritage Site in South Africa. Recreational caving has occurred there since the 1960s. Fossils found there starting in 2013 were, in 2015, determined to be a previously unknown extinct species of hominin named Homo naledi.

Names

In the 1980s, the names "Empire", "Westminster", and "Rising Star" were used interchangeably.[1]

The species's name, naledi (Sesotho for "star"), and the "Dinaledi Chamber" (incorporating the Sotho word for "stars")[2] were so named by members of the Rising Star Expedition in reference to the species and chamber's location in Rising Star Cave.

A portion of the cave, used by the excavation team en route to the Dinaledi Chamber, is called "Superman's Crawl" because most people can fit through only by holding one arm tightly against the body and extending the other above the head, in the manner of Superman in flight.

The Superman Crawl opens into the "Dragon's Back Chamber," which includes an approximately 15 m (49 foot) exposed climb up a ridge of a sharp-edged dolomite block that fell from the roof sometime in the distant past. This block is the so-called Dragon's Back, so named because the climbing route appears to progress from the tail to the head along the spiked spine of a mythical beast.

History

Geologists think the cave in which the fossils were discovered is no older than three million years.[3]

The cave was explored in the 1980s by the Speleological Exploration Club (SEC), a local branch of the South African Speleological Association (SASA).[1]

Discovery of fossils in "Dinaledi Chamber"

On 13 September 2013, while exploring the Rising Star cave system, recreational cavers Rick Hunter and Steven Tucker of the Speleological Exploration Club (SEC) found a narrow, vertically oriented "chimney" or "chute" measuring 12m (39feet) long with an average width of 20cm (10inches).[4] [5] [6] Then Hunter discovered a room 30m (100feet) underground (Site or, the Dinaledi Chamber), the surface of which was littered with fossil bones. On 1 October, photos of the site were shown to Pedro Boshoff and then to Lee Berger, both of the University of the Witwatersrand.[7]

The arrangement of bones, as well as several survey pegs, suggested "someone had already been there" as recently as a few decades earlier. The appearance of limited fossilisation initially led the explorers to think the bones were from the last caver into the chamber, who had subsequently never made it back out alive.

2013 and 2014 excavations

Berger organized an expedition to excavate the fossils, which started on 7 November 2013. The expedition was funded by the South African National Research Foundation and the National Geographic Society.[8] [9]

The excavation team enlisted six paleoanthropologists, all of whom were women, who could pass through an opening only 18 cm (7 inches) wide to access the Dinaledi Chamber.[10] [11] Those chosen were Hannah Morris, Marina Elliott, Becca Peixotto, Alia Gurtov, Lindsay Eaves, and Elen Feuerriegel.[12] They have since been nicknamed the Underground Astronauts.[13]

The Dinaledi Chamber was assigned the designation (or ) and was excavated by these six members of the Rising Star Expedition during November 2013. More than 1,200 fossil elements were recovered and catalogued in November 2013,[14] representing at least a dozen individuals.[15] Only 20 out of 206 bones in the human body were not found in the cave as of Summer 2014.[16] By April 2014, between two localities, 1,754 specimens were recovered.[17]

The layered distribution of the bones [in clay-rich sediments] suggests that they had been deposited over a long period of time, perhaps centuries. Only one square meter of the cave chamber has been excavated; other remains might still be there.[8] [18] [19]

On 20 February 2014, Rick Hunter, Lee Berger, John Hawks, Alia Gurtov, and Pedro Boshoff returned to Rising Star to evaluate a second potential site. The site, designated UW-102 (or, aka Lesedi Chamber),[20] was found by cavers Rick Hunter and Steve Tucker on the last day of the first Rising Star Expedition, and limited excavation began in April 2014.[21]

, fossils of at least fifteen individuals, amounting to 1,550 specimens, had been excavated from the cave.[22] About 300 bone fragments were collected from the surface of the Dinaledi Chamber, and about 1,250 fossil specimens were recovered from the chamber's main excavation pit, Unit 3.[4] The fossils include skulls, jaws, ribs, teeth, bones of an almost complete foot, of a hand, and of an inner ear. The bones of both old and young individuals, as well as infants, were found.[22]

The 15 partial skeletons, which were found in a small underground chamber, invite speculation on the circumstances of their location. Paleoanthropologist John D. Hawks, from the University of Wisconsin-Madison, who is a member of the team, has stated that the scientific facts are that all the bones recovered are hominin, except for those of one owl; there are no signs of predation, and there is no predator that accumulates only hominins this way; the bones did not accumulate there all at once. There is no evidence of rocks or sediment having dropped into the cave from any opening in the surface; no evidence of water flowing into the cave carrying the bones into the cave.[4] [23] [24]

Hawks concluded that the best hypothesis is that the bodies were deliberately placed in the cave after death, by other members of the species.[25] Berger et al. suggest that "these individuals were capable of ritual behaviour." They speculate the placing of dead bodies in the cave was a ritualistic behaviour, a sign of symbolic thought.[26] "Ritual" here means an intentional and repeated practice (disposing of dead bodies in the cave), and not implying any type of religious ritual. This hypothesis has been criticised for its improbability.[27] [28]

A study involving the statistical reconstruction of hominin evolutionary trees from skull and tooth measurements, originally indicated that the most likely age for H. naledi was 912 kya.[29] [30] [31]

A collaborative workshop involving 54 local and international scientists took place in May 2014 at the University of the Witwatersrand,[32] On 10 September 2015, the fossils were publicly unveiled and given the name Homo naledi.[33] [4]

Dating

The fossils of the Dinaledi chamber have been dated to between 335,000 and 236,000 years ago, long after much larger-brained and more modern-looking hominins had appeared.[34] [35] Geologists estimate that the cave in which the fossils were discovered is no older than three million years,[3] and the ages for flowstone where the fossils were recovered from was interpreted to be deposited between 236,000 and 414,000 years ago.[34]

Rock engravings

In 2023, Berger published a preliminary report that described rock engravings on a pillar in the Hill Antechamber, near where bodies were found. They are "deeply impressed cross-hatchings and other geometric shapes. The surfaces bearing these engravings appear to have been prepared and smoothed." Berger goes on to note, "If confirmed, the antiquity, intentionality, and authorship of the reported markings will have profound archaeological implications, as such behaviors are otherwise widely considered to be unique to our species, Homo sapiens." However it does concede the discovery requires more work to confirm who made the markings and when.[36] In addition, Berger found evidence of extensive fire use in the cave, presumably to provide light.[37]

Geology

The Rising Star cave system lies in the Bloubank River valley, 2.2 km west of Sterkfontein Cave. It comprises an area of 250 × 150 m of mapped passageways situated in the core of a gently west dipping (17°) open fold, and it is stratigraphically bound to a 15–20 m-thick, stromatolitic dolomite horizon in the lower parts of the Monte Christo Formation. This dolomite horizon is largely chert-free but contains five thin (<10 cm) chert marker horizons that have been used to evaluate the relative position of chambers within the system. The upper contact is marked by a 1–1.3 m-thick, capping chert unit that forms the roof of several large cave chambers.[4] The height above sea level is 1,450 m for the Dinaledi Chamber's floor.[38]

See also

External links

Notes and References

  1. Book: Paul Courbon. Atlas of the Great Caves of the World. Cave Books. 1989. 38. 0939748215. Empire Cave [Western Transvaal]: 4010 m; Empire/Westminster/Rising Star Cave. Explored by SASA and Free Cavers.
  2. [Sesotho]
  3. News: New Species in Human Lineage Is Found in a South African Cave. New York Times. 10 September 2015. 2015-09-10. 0362-4331. John Noble. Wilford. 4 July 2018. https://web.archive.org/web/20180704004306/https://www.nytimes.com/2015/09/11/science/south-africa-fossils-new-species-human-ancestor-homo-naledi.html. live.
  4. Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa . . 2015 . 2050-084X . 4559842 . e09561 . 4 . 10.7554/eLife.09561 . Dirks . Paul H. G. M. . Roberts . Eric M. . et al. . 26354289 . free .
  5. Web site: Tucker . Steven . Rising Star Expedition . Speleological Exploration Club . 13 November 2013 . 8 September 2015 . 25 September 2015 . https://web.archive.org/web/20150925130112/http://www.sec-caving.co.za/2013/11/rising-star-expedition.html . live .
  6. Web site: SEC-Caving: Rising Star Expedition Finds over 1,000 Hominid Fossils. André Doussy. sec-caving.co.za. 20 January 2015. 20 January 2015. https://web.archive.org/web/20150120192749/http://www.sec-caving.co.za/2014/07/rising-star-expedition-finds-over-1000.html. live.
  7. Web site: Yong . Ed . 6 Tiny Cavers, 15 Odd Skeletons, and 1 Amazing New Species of Ancient Human . 10 September 2015 . . 2015-09-13 . 14 September 2015 . https://web.archive.org/web/20150914115034/http://www.theatlantic.com/health/archive/2015/09/homo-naledi-rising-star-cave-hominin/404362/ . live .
  8. News: Greenfieldboyce . Nell . South African Cave Yields Strange Bones Of Early Human-Like Species . 10 September 2015 . . 2015-09-10 . 7 July 2018 . https://web.archive.org/web/20180707100428/https://www.npr.org/sections/health-shots/2015/09/10/437249183/south-african-cave-yields-strange-bones-of-early-human-like-species . live .
  9. Web site: Rising Star Expedition - National Geographic (blogs). https://web.archive.org/web/20150909064912/http://voices.nationalgeographic.com/blog/rising-star-expedition/?order=asc. dead. 2015-09-09. nationalgeographic.com.
  10. Web site: Staff . Rising Star Expedition Launched . . 6 November 2013 . 2015-09-08 . dead . https://web.archive.org/web/20150913115356/http://www.wits.ac.za/newsroom/newsitems/201312/21993/news_item_21993.html . 13 September 2015 . dmy-all .
  11. Web site: Brahic . Catherine . Bone Bonanza: Chamber of Secrets Yields Human Remains . . 26 November 2014 . 2015-09-08 . 25 September 2015 . https://web.archive.org/web/20150925132200/https://www.newscientist.com/article/mg22429970-400-bone-bonanza-chamber-of-secrets-yields-human-remains/ . live .
  12. News: Smith. David. 'Small spelunkers required': the ad that led to the discovery of Homo naledi. 10 January 2016. The Guardian. 10 September 2015. 30 December 2015. https://web.archive.org/web/20151230013555/http://www.theguardian.com/science/2015/sep/10/homo-naledi-small-spelunkers-required-how-an-advert-led-to-the-discovery-of-homo-naledi. live.
  13. News: Feltman. Rachel. Meet the six female 'underground astronauts' who recovered our newest relative. 10 January 2016. The Washington Post. September 10, 2015. 6 July 2018. https://web.archive.org/web/20180706163339/https://www.washingtonpost.com/news/speaking-of-science/wp/2015/09/10/meet-the-six-female-underground-astronauts-who-recovered-our-newest-relative/. live.
  14. Web site: Final Day of Excavations. Andrew Howley. nationalgeographic.com. 2 December 2013. 4 December 2013. https://web.archive.org/web/20131204213045/http://newswatch.nationalgeographic.com/2013/11/27/final-day-of-excavations/. dead.
  15. News: Anthropologist, 'underground astronaut' strike fossil gold in South Africa dig . 9 December 2013 . 10 December 2013 . https://web.archive.org/web/20131210221031/http://www.news.wisc.edu/22375 . live .
  16. News: Anthropology Prof. John Hawks and UW-Madison students dig up crucial remnants of early hominids . 21 September 2014 . 22 December 2014 . https://web.archive.org/web/20141222095037/http://www.isthmus.com/isthmus/article.php?article=43599 . live .
  17. News: Rising Star Empire Cave 2014 Annual Report . Lee R. Berger . 7 May 2015 . 24 September 2015 . https://web.archive.org/web/20150924093716/http://www.sahra.org.za/sahris/heritage-reports/rising-star-empire-cave-2014-annual-report . dead .
  18. Web site: New Species Of Human Discovered In South Africa . 10 September 2015 . Justine . Alford . 21 September 2015 . 24 May 2016 . https://web.archive.org/web/20160524163630/http://www.iflscience.com/editors-blog/newly-discovered-human-ancestor-likely-ritualistically-disposed-its-dead . dead .
  19. News: Shreeve . Jamie . New Human Ancestor Elicits Awe—and Many Questions . . 10 September 2015 . 2015-09-17 . 16 November 2018 . https://web.archive.org/web/20181116055739/https://news.nationalgeographic.com/2015/09/150910-homo-naledi-human-ancestor-species-reaction-science/ . dead .
  20. John Hawks, Marina Elliott, Peter Schmid, Steven E. Churchill et al.: New fossil remains of Homo naledi from the Lesedi Chamber, South Africa. In: eLife Sciences 6. May 2017. Projects: Taphonomic analysis of the Rising Star hominin assemblage; Homo naledi and Australopithecus sediba. . Fig. 2
  21. News: Scientists Return to Explore a Second Fossil Chamber. Hawks. John. 22 February 2014. 21 February 2014. https://web.archive.org/web/20140221014424/http://newswatch.nationalgeographic.com/2014/02/20/scientists-return-to-explore-a-second-fossil-chamber/. dead.
  22. Web site: Shreeve . Jamie . 10 September 2015 . This Face Changes the Human Story. But How? . dead . 2023-05-21 . . 21 May 2023 . https://web.archive.org/web/20230521133010/https://www.nationalgeographic.com/history/article/150910-human-evolution-change .
  23. Web site: Drake . Nadia . Nadia Drake . Mystery Lingers Over Ritual Behavior of New Human Ancestor . 15 September 2015 . . 2015-09-16 . 3 November 2015 . https://web.archive.org/web/20151103060421/http://news.nationalgeographic.com/2015/09/150915-humans-death-burial-anthropology-Homo-naledi/ . dead .
  24. Web site: McKensie . David . Homo naledi: Scientists find ancient human relative . . 10 September 2015 . . 2015-09-13 . 2 November 2015 . https://web.archive.org/web/20151102091548/http://www.cnn.com/videos/world/2015/09/10/human-ancestor-species-discovered-south-africa-mckenzie-pkg.cnn/video/playlists/ancient-discoveries . live .
  25. Web site: Staff . Dawn of Humanity . 10 September 2015 . . 2015-09-14 . Documentary time mark: 1h 40 min . 4 October 2018 . https://web.archive.org/web/20181004235332/http://www.pbs.org/wgbh/nova/evolution/dawn-of-humanity.html . live .
  26. Web site: Ghosh . Pallab . New human-like species discovered in S Africa . . 10 September 2015 . 2015-09-10 . 4 August 2019 . https://web.archive.org/web/20190804090316/https://www.bbc.co.uk/news/science-environment-34192447 . live .
  27. News: Sample . Ian . Homo naledi: new species of ancient human discovered, claim scientists . The Guardian . 10 September 2015 . 2016-01-06 . 10 September 2015 . https://web.archive.org/web/20150910152306/http://www.theguardian.com/science/2015/sep/10/new-species-of-ancient-human-discovered-claim-scientists . live .
  28. Web site: Debate Erupts over Strange New Human Species. Wong. Kate. . 2016-07-06. 13 April 2016. https://web.archive.org/web/20160413215801/http://www.scientificamerican.com/article/debate-erupts-over-strange-new-human-species/. live.
  29. Dembo . Mana . Radovčić . Davorka . Garvin . Heather M. . Laird . Myra F. . Schroeder . Lauren . Scott . Jill E. . Brophy . Juliet . Ackermann . Rebecca R. . Musiba . Chares M. . 2016-08-01 . The evolutionary relationships and age of Homo naledi: An assessment using dated Bayesian phylogenetic methods . Journal of Human Evolution . 97 . 17–26 . 10.1016/j.jhevol.2016.04.008 . 27457542. 2016JHumE..97...17D . 2164/8796 . free .
  30. Web site: New dating suggests younger age for Homo naledi . Bower . Bruce . 5 July 2016 . 2016-07-06 . 5 July 2016 . https://web.archive.org/web/20160705142657/https://www.sciencenews.org/article/new-dating-suggests-younger-age-homo-naledi . live .
  31. Thackeray . J. Francis . 2015 . Estimating the age and affinities of Homo naledi . South African Journal of Science . 111 . 11/12 . 2 . 10.17159/sajs.2015/a0124 . free .
  32. Crowdsourcing digs up an early human species . Nature News & Comment . 2015 . 10.1038/nature.2015.18305 . 22 September 2015 . 11 September 2015 . https://web.archive.org/web/20150911100757/http://www.nature.com/news/crowdsourcing-digs-up-an-early-human-species-1.18305 . live . Callaway . Ewen . 525 . 7569 . 297–298 . 26381960 . 2015Natur.525..297C .
  33. Berger . Lee R. . Lee Rogers Berger . etal . Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa . . 10 September 2015 . 4 . 10.7554/eLife.09560 . free . 26354291 . 4559886 .
  34. Dirks. Paul H.G.M.. Eric M.. Roberts. Hannah. Hilbert-Wolf. Jan D.. Kramers. John. Hawks. Anthony. Dosseto. Mathieu. Duval. Marina. Elliott. Mary. Evans. Rainer. Grün. John. Hellstrom. Andy I.R.. Herries. Renaud. Joannes-Boyau. Tebogo V.. Makhubela. Christa J.. Placzek. Jessie. Robbins. Carl. Spandler. Jelle. Wiersma. Jon. Woodhead. Lee R.. Berger. 2. 9 May 2017 . The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa . eLife . 6 . e24231 . 10.7554/eLife.24231 . 28483040. 5423772. free .
  35. News: Rincon . Paul . Amazing haul of ancient human finds unveiled . . 9 May 2017 . 9 May 2017 . Paul Rincon . 9 May 2017 . https://web.archive.org/web/20170509122704/http://www.bbc.com/news/science-environment-39842975 . live .
  36. 241,000 to 335,000 Years Old Rock Engravings Made by Homo naledi in the Rising Star Cave system, South Africa . . Lee R. . Berger . John D. . Hawks. Agustin . Fuentes. Dirk van . Rooyen. Mathabela . Tsikoane. Maropeng . Ramalepa. Samuel . Nkwe. Keneiloe . Molopyane . 1 . July 11, 2023 . 12 . 10.7554/eLife.89102.1 . free .
  37. Web site: Homo naledi may have made etchings on cave walls and buried its dead . . Alison . George . June 5, 2023 . 2024-01-01.
  38. Web site: New species of extinct human found in cave may rewrite history. New Scientist. 23 September 2015. 23 September 2015. https://web.archive.org/web/20150923185613/https://www.newscientist.com/article/mg22730383-700-new-species-extinct-human-found-in-cave-may-rewrite-history/. live.
  39. Web site: Watch Unknown: Cave of Bones | Netflix Official Site . .

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