Swimming with Dinosaurs

Dinosaurs left plenty of bones, but some also created another type of fossil: preserved track marks. A handful of these tracks were made from swimming dinosaurs, and a new paper in the Chinese Science BulletinA new Early Cretaceous dinosaur track assemblage and the first definite non-avian theropod swim trackway from China (open access) – reports on the discovery of one such find.

Timothy L. Clarey’s new article on these tracks is called Dinosaurs Swimming out of Necessity, but the “necessity” conclusion is entirely his own. His article is quite similar to one from Brian Thomas published in January which we looked at in Stampede? For instance both Thomas and Clarey chose to claim in their opening paragraphs that, in the present day, it is very difficult to form footprints that will eventually be preserved as fossils – here’s Clarey’s opener:

What’s so fascinating about dinosaur tracks? Maybe it’s because their many mysteries beg for solutions. For instance, because tracks in mud are so short-lived today, how did dinosaur tracks ever preserve in the first place? Newly described prints bolster biblical creation’s explanation of dinosaur footprints.

It may be true that it’s hard to preserve footprints in mud, but it’s not so improbable once you consider the shear number of footprints that would have been made over the more than 180 million years of the Mesozoic Era. Clarey never does explain, meanwhile, how “biblical creation” suddenly makes preservation so much easier – not even a “footprints need to be preserved rapidly” claim (which is false, by the way).

The tracks discovered fall into a number of categories. There is a trackway formed by a swimming theropod; some more by non-swimming theropods; another track created by a sauropod; and finally a herd of ornithopods made tracks of their own in the area. Clarey says:

The scientists determined at least one of the theropods was partly afloat as its feet swiped the underwater mud. Its fifty-foot trackway shows a number of tip-toe scratches and claw scrapings. A second theropod, walking in the same direction and on the same horizon as the first, was apparently wading in the water as it left more complete footprints. These scientists interpret the tracks were made as these dinosaurs crossed a river, possibly during a flood event.

The paper doesn’t actually talk about rivers or floods at all (though it does mention that the deposit the tracks are in is “fluvial,” meaning that it must have had something to do with a river), and they say that they can’t even determine what direction the current was flowing in. Despite this lack of real information about the site, Clarey forges ahead with his Great Flood interpretation:

The study authors estimated both dinosaurs had hip heights of just under three feet—from sole to hip—but if they had similar leg height, why didn’t they produce similar tracks? The evidence of both swimming and wading indicates rapid fluctuations in water depth. The first dinosaur was able to wade through the shallow water, while the second, same-sized dinosaur—apparently just moments later—had to swim as the water level rose quickly.

Another thing they don’t know: whether the swimming theropod came before or after the walking ones – Clarey simply assumes the latter, as it is the only option that will fit his explanation. What we do know from the juxtaposition of swimming and walking is that there was a change in water level, but in what direction or over how long of a period we simply have no idea (it must have been short, yes, but enough so to justify the descriptor of “rapid”?).

The parallel trackways of the sauropod and the ornithopods (all within several feet of one another) also indicate they had been wading through the water. The hip heights of these animals were higher than the two theropods, so they evidently had no need to swim.

Clarey claims that the tracks of the ornithopods and the sauropod were paralell and close together – indeed, that all the animals were travelling in the same direction at more-or-less the same time and place – but I can’t find evidence for that in the paper. The swimming theropod and the sauropod were close and largely parallel, yes (the sauropod curves towards and then away from the theropod), while some of the walking theropods and ornithopods were similarly arranged, but lacking a map of the site I can’t find evidence that these two groups are both either nearby or parallel. They might be, but I can’t tell – but for Clarey, they must be.

Creation scientists have suggested many animals swam to escape the Flood waters. These trackways in Sichuan confirm that water overwhelmed the dinosaurs and forced them to swim for their lives for as long as they could, clearly following the Flood events and timeline from the book of Genesis. This deluge created rapid fluctuations in water levels—its tsunami-like waves quickly covering the land surface, and then just as rapidly, draining off. In contrast to the Flood’s grand-scale destruction and deposition, evolutionists call upon dinky, local river floods to explain these sites.

“Dinky, local river floods”? Is this some kind of “I’ve got the biggest flood” dick-waving competition that creationists are unilaterally engaging in? Bigger isn’t necessarily better, guys.

Now, I would argue that the evidence – such as it is – is not favourable for Clarey’s tsunami idea. The paper describes their tracksite with the following details:

In addition to the vertebrate footprints, invertebrate traces are also preserved on the surface. Most common are vertical burrows (Scoyenia isp.) that indicate a non-marine shallow water environment. Mudcracks suggest a change in water depth and a short-term exposure to the air. Developed ripple marks are also widespread.

Elsewhere they mention that one of the walking theropod tracks had been exposed “to later weathering and disturbance by vegetation.” Clarey paints a picture of dinosaurs racing from a tsunami that gains height as time progresses. This discription shows, however, that the area then dried out for a while, perhaps even long enough for plants to grow. Clarey does have the waters receding after the tsunami, but this presents a problem: aren’t these waves supposed to be depositing and/or eroding sediment? You see, if the dinosaurs are running away from the wave they must be at it’s front, but the wave must have done no erosion or deposition until the area dried out and mudcracks formed. Is that compatible with the model Clarey is using?

There are a few other problems. For one, the aforementioned walking theropod was said to be making prints in what was already “soft, wet sediments” (emphasis original), which means that the ground must have been softened by an earlier wave (or other processes, perhaps). But if there had been such a wave, how did these dinosaurs survive it.

Another issue is that the paper calculates that the water level for the swimming theropod as being hip-height, which they inferred to be 90 cm (about 3 feet). The mode of “swimming” was really only half-floating, with the feet still touching the ground with every step. Clarey believes that this is somehow happening in a tsunami situation, but the theropod is not being propelled forwards by the water – if it were, that would be a dead give-away for current direction if nothing else, and should be evident from track spacing.

Given all this I think a stronger case could be made for the water receding at the time that the tracks were made – the ground had been softened by a long submersion, while there wouldn’t be too much more deposition or erosion before the mud would be exposed to the air and could dry. It should go without saying that this explanation is not compatable with Clarey’s tsunamis, as the dinosaurs should be dead already.

Clarey goes on to mention the earlier story covered by Thomas, before concluding:

The evidence for the Flood is found all over the world. Trackways of swimming dinosaurs on many continents confirm the global extent of the cataclysm. Dinosaur track formation clearly required abnormal and catastrophic circumstances. These desperate creatures ran, waded, and swam for as long as they could, but all succumbed to the overwhelming power of God’s judgment as reported in Genesis.

Those poor dinosaurs, who died for our unspecified sins.

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One thought on “Swimming with Dinosaurs

  1. Were YECs citing tsunamis in support of the Biblical flood description before the devastating events of 2004 and 2011 (as one might expect of relevantly scientifically-literate people but perhaps not of ideologues)?

    I hadn’t come across articles by this Timothy L Clarey before, but he has also co-authored the latest online ICR article:
    http://www.icr.org/article/7412/

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