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Monday, 24 August 2020

Grand Canyon Footprints Refute YEC Claim

Manakacha Trackway
Photo credit: Stephen Rowland
Cliff Collapse Reveals 313-million-year-old Fossil Footprints in Grand Canyon National Park - Grand Canyon National Park (U.S. National Park Service)

Another terrible day for creationists as another dogma collapses like a house built by fools on sand.

Their problem is that new evidence, revealed by chance by the collapse of a cliff in the Grand Canyon, proves beyond doubt that their notion of the Grand Canyon being built by rushing flood-waters during Noah's Flood, is wrong and geologists are right. The strata revealed by the canyon are not the result of sediment deposited by this supposed flood and nor was the canyon formed by a raging torrent as ther flood water 'ran off' (presumably over the edge of the flat Earth!).

Grand Canyon Horseshoe Bend
Photo credit: AP Photo/Ross D. Franklin
Of course, the existence of the famous horseshoe bend in the course of the Colorado river should have told them that the canyon could not have been formed by rushing water because rushing water does not make a 180 plus degree turn and head off in the other direction, but they have managed to turn a blind eye to that contradictory evidence and still claim the canyon as proof of the Bible being literal history.

So, it will be interesting to see how Ham, Hovind and the other frauds who sell fake 'proofs' to their gullible dupes for money, handle this latest piece of evidence. The evidence is that of footprints of a tetrapod vertebrate of some sort, made in wind-blown soft sand, and subsequently covered by a preserving deposit of mud in a way that did not destroy the impressions in soft sand.

The news release by the National Parks Service, explains the discovery and its significance:

GRAND CANYON, AZ.

Paleontological research has confirmed a series of recently discovered fossils tracks are the oldest recorded tracks of their kind to date within Grand Canyon National Park. In 2016, Norwegian geology professor, Allan Krill, was hiking with his students when he made a surprising discovery. Lying next to the trail, in plain view of the many hikers, was a boulder containing conspicuous fossil footprints. Krill was intrigued, and he sent a photo to his colleague, Stephen Rowland, a paleontologist at the University of Nevada Las Vegas.

The trailside tracks have turned out to be even more significant than Krill first imagined. “These are by far the oldest vertebrate tracks in Grand Canyon, which is known for its abundant fossil tracks" says Rowland. "More significantly," he added, "they are among the oldest tracks on Earth of shelled-egg-laying animals, such as reptiles, and the earliest evidence of vertebrate animals walking in sand dunes."

The track-bearing boulder fell from a nearby cliff-exposure of the Manakacha Formation. The presence of a detailed geologic map of the strata along the Bright Angel Trail, together with previous studies of the age of the Manakacha Formation, allowed the researchers to pin down the age of the tracks quite precisely to 313 +/- 0. 5 million years.

The newly discovered tracks record the passage of two separate animals on the slope of a sand dune. Of interest to the research team is the distinct arrangement of footprints. The researchers’ reconstruction of this animal’s footfall sequence reveals a distinctive gait called a lateral-sequence walk, in which the legs on one side of the animal move in succession, the rear leg followed by the foreleg, alternating with the movement of the two legs on the opposite side. “Living species of tetrapods―dogs and cats, for example―routinely use a lateral-sequence gait when they walk slowly,” says Rowland. “The Bright Angel Trail tracks document the use of this gait very early in the history of vertebrate animals. We previously had no information about that.” Also revealed by the trackways is the earliest-known utilization of sand dunes by vertebrate animals.

The research finding of the team who investigated this find were published open access recently in the online journal, PLOS ONE. Note how the main interest for the scientists was that these were the tracks of an early tetrapedal amniote and what they reveal of the gait of this basal species. The casual refutation of YEC claims was purely incidental. Once again, YECism has been refuted by science simply by discovering the facts.

Abstract

We report the discovery of two very early, basal-amniote fossil trackways on the same bedding plane in eolian sandstone of the Pennsylvanian Manakacha Formation in Grand Canyon, Arizona. Trackway 1, which is Chelichnus-like, we interpret to be a shallow undertrackway. It displays a distinctive, sideways-drifting, footprint pattern not previously documented in a tetrapod trackway. We interpret this pattern to record the trackmaker employing a lateral-sequence gait while diagonally ascending a slope of about 20°, thereby reducing the steepness of the ascent. Trackway 2 consists only of aligned sets of claw marks. We interpret this trackway to be a deeper undertrackway, made some hours or days later, possibly by an animal that was conspecific with Trackmaker 1, while walking directly up the slope at a speed of approximately 0.1 m/sec. These trackways are the first tetrapod tracks reported from the Manakacha Formation and the oldest in the Grand Canyon region. The narrow width of both trackways indicates that both trackmakers had relatively small femoral abduction angles and correspondingly relatively erect postures. They represent the earliest known occurrence of dunefield-dwelling amniotes―either basal reptiles or basal synapsids―thereby extending the known utilization of the desert biome by amniotes, as well as the presence of the Chelichnus ichnofacies, by at least eight million years, into the Atokan/Moscovian Age of the Pennsylvanian Epoch. The depositional setting was a coastal-plain, eolian dunefield in which tidal or wadi flooding episodically interrupted eolian processes and buried the dunes in mud.

Rowland SM, Caputo MV, Jensen ZA (2020)
Early adaptation to eolian sand dunes by basal amniotes is documented in two Pennsylvanian Grand Canyon trackways.
PLoS ONE
15(8): e0237636. DOI:10.1371/journal.pone.0237636

Copyright: © 2020 The Authors. Published by PLOS
Open access.
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)

Perhaps a creationist would like to explain how a raging torrent of water, sufficient to gouge out a massive canyon would leave soft sand completely undisturbed, to preserve the footprints in it.







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