The Cores of this Scientific Paper are Tuff to beat!

Archeology, Geology, Human Evolution, Human Origins, Lithic Analysis, Lithics, Palaeobiology, Palaeoecology, Palaeontology, Palaeozoology, Paleoecology, Paleontology, Radiometric Dating, Science

Sediment cores retrieved from the Pleistocene Olduvai Basin by the Olduvai Gorge Coring Project (OGCP) provide a high resolution record of tuffs and other volcaniclastic deposits, together with a lacustrine sedimentary record full of paleoenvironmental indicators. Correlating tuffs between the cores and outcrops at Olduvai, where these tuffs are identified at paleoanthropologically important sites, is critical for applying the new paleoenvironmental data to the conditions under which hominins lived. Tuffs and other volcaniclastic deposits from three cores were analyzed for mineral assemblages and glass and mineral major element compositions (feldspar, augite, hornblende, titanomagnetite, and glass where possible) to compare to published geochemical fingerprint data, based on marker tuffs from outcrop equivalents at Olduvai Gorge. In combination with stratigraphic position, these mineralogical and geochemical data were used to correlate between the cores and outcrops, providing direct temporal tie-lines between the cores and sites of paleoanthropological interest. Direct correlations are most certain for Olduvai Bed I, where all major tuff markers from outcrop are identified for one or more of the three core sites, and for the upper part of the underlying Ngorongoro Formation, which includes the Coarse Feldspar Crystal Tuff (CFCT) and Naabi ignimbrites exposed in the oldest Pleistocene exposures of the Western Gorge. Also characterized were the mineral and glass compositions of tuffs and ignimbrites pre-dating the oldest exposed outcrop units, extending our record of explosive events from the Ngorongoro Volcano. While no specific correlations can be confirmed between individual Bed II tuffs in the cores and in outcrops, correlations are possible between the cores themselves (using newly identified tuff compositions), and some potential correlations (non-unique, based on individual mineral phases) between core and outcrop can be used in conjunction with other stratigraphic tools to help constrain the intervals in question.

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The upper limb of Paranthropus boisei from Ileret, Kenya

Anatomy, Archaeology, Archeology, Evolution, Geology, Human Evolution, Human Origins, Journal of Human Evolution, Lithic Analysis, Lithics, Palaeoanthropology, Palaeobiology, Palaeontology, Paleobiology, Paleontology

Figure 3. Stratigraphic section (left) shown with the image (right) of the outcrop highlighting the positions of the three major tuffs. All hominin fossils were found on the surface or in secondarily deposited sediment below the Ileret Tuff (1.52 ± 0.01 Ma). Some of the remains were found above the Lower Ileret Tuff (1.53 ± 0.01 Ma) indicating that the bones must have been buried above it. The large excavation area is visible on the right side of the outcrop and gully; the lower footprint level (Bennett et al., 2009Dingwall et al., 2013Hatala et al., 2017) is exposed on the left side of the image. All fragments of KNM-ER 47000 were located on the surface of the lower portion of the outcrop or secondarily buried in sediment eroded from the drainage that extends up the slope from the excavation site toward the right margin of the picture.

Paranthropus boisei was first described in 1959 based on fossils from the Olduvai Gorge and now includes many fossils from Ethiopia to Malawi. Knowledge about its postcranial anatomy has remained elusive because, until recently, no postcranial remains could be reliably attributed to this taxon. Here, we report the first associated hand and upper limb skeleton (KNM-ER 47000) of P. boisei from 1.51 to 1.53 Ma sediments at Ileret, Kenya. While the fossils show a combination of primitive and derived traits, the overall anatomy is characterised by primitive traits that resemble those found in Australopithecus, including an oblique scapular spine, relatively long and curved ulna, lack of third metacarpal styloid process, gracile thumb metacarpal, and curved manual phalanges. Very thick cortical bone throughout the upper limb shows that P. boisei had great upper limb strength, supporting hypotheses that this species spent time climbing trees, although probably to a lesser extent than earlier australopiths. Hand anatomy shows that P. boisei, like earlier australopiths, was capable of the manual dexterity needed to create and use stone tools, but lacked the robust thumb of Homo erectus, which arguably reflects adaptations to the intensification of precision grips and tool use. KNM-ER 47000 provides conclusive evidence that early Pleistocene hominins diverged in postcranial and craniodental anatomy, supporting hypotheses of competitive displacement among these contemporaneous hominins.

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Figure 1. Right upper limbs of a modern human (left), chimpanzee (center), and KNM-ER 47000 (right), which preserves lateral portions of the scapula, the distal portion of the humerus, most of the ulna, and most of metacarpals (MCs) 1-3 and proximal phalanges 2-4. KNM-ER 47000 has primitive traits including a gracile thumb MC, lack of MC 3 styloid process, curved phalanges with prominent flexor sheaths, a long and curved ulna, a humerus with thick cortical bone and a prominent brachioradialis flange, and obliquely oriented scapular spine. Derived traits include a relatively long thumb, short manual phalanges, and a lateral scapular glenoid orientation. Scale bar at right is 10 cm.

Three reasons the Cerutti Mastodon was not manipulated by hominins

America, Archaeogenetics, Archaeology, Archeogenetics, Archeology, Biological Science, DNA, Evolution, Experimental Archaeology, Experimental Archeology, Genetics, Human Evolution, Human Origins, Lithic Analysis, Lithics, Palaeoanthropology, Palaeobiology, Palaeontology, Palaeozoology, Paleobiology, Radiometric Dating, Science

A team of scientists recently announced an extraordinary claim that the 130,000 Cerutti Mastodon was manipulated by hominins.

“I have read that paper and I was astonished by it,” archaeologist Donald Grayson of the University of Washington. “I was astonished not because it is so good, but because it is so bad. Cracked bones and chipped stones at a fossil site might mean anything”, said Grayson. “It is quite another thing to show that people, and people alone, could have produced those modifications. The study doesn’t take that step, he said, “making this a very easy claim to dismiss.”

Gary Haynes of the University of Nevada Reno had this to say, “The paper states that the bones were being exposed by a backhoe. These pieces of heavy equipment weigh seven to fifteen tons or more, and their weight on the sediments would have crushed bones and rocks against each other.” When asked, Holen, the study leader, said that it “was very easy to tell the difference” between fractures made by stone hammers and those seen in bones crushed by bulldozers. He did not elaborate on how the differences manifest. “He’s pretty much dead wrong — there’s no definable difference,” Haynes said. A similar fossil dispute broke out in 2015 over a 24,000 year old mammoth in Maryland, he noted, shown to be fractured by heavy equipment. Also troubling, the “hammer” and “anvil” stones described in the paper don’t unequivocally look like tools, said Michael Waters of Texas A&M’s Center for the Study of the First Americans.

Michael Waters of Texas A&M’s Center for the Study of the First Americans noted that the “hammer” and “anvil” stones described in the paper don’t unequivocally look like tools. The study also runs afoul of the mounting genetic evidence, which indicates that the first people to reach the Americas and eventually give rise to modern Native Americans arrived no earlier than 25,000 years ago.”