Neuquensaurus australis
AI-Generated image (ChatGPT Latest)
Evolution works only with whatever variation happens to be available at the time, favouring traits that improve reproductive success in the short term. Unlike the imaginary “intelligent designer” of creationist fantasy, evolution has no foresight, no long-term plan, and no concern for what happens once reproduction has been achieved. The result is not elegant perfection, but a patchwork of compromises that work well enough for long enough.
That is why nature is full of structures and processes that serve an immediate purpose while carrying harmful longer-term consequences. Ageing itself is one obvious example, as damage accumulates, repair systems falter, and tissues and organs gradually fail. Cancers and degenerative diseases are others, arising when biological control mechanisms begin to malfunction. A genuinely intelligent designer would have no excuse for such shoddy, failure-prone systems; evolution, by contrast, explains them perfectly.
In humans, physical and reproductive fitness generally peaks in early adulthood, then declines steadily with age, until the very old, if they live that long, may become frail and dependent. From an evolutionary perspective, this makes perfect sense: once genes have been passed on, natural selection becomes progressively less effective at eliminating traits that cause harm later in life. What looks like incompetence from a design perspective is exactly what we should expect from an undirected evolutionary process.
And this is not some recent peculiarity of human biology, but a deep feature of evolution itself. A recent study by researchers from Brazil, Germany and Argentina illustrates the point with two South American sauropod dinosaurs, the Brazilian Uberabatitan and the Argentinean Neuquensaurus. These giant herbivores could apparently rear up on their hind limbs to reach high foliage, and perhaps also gain advantages in defence or display. But that ability came at a cost. As body size increased, so did the mechanical stress on the femur, making the posture progressively more difficult to sustain. In other words, evolution had produced a useful adaptation, but not a perfect one. The benefit came with a built-in structural penalty.
The researchers reached this conclusion by applying computational techniques from mechanical engineering to digital models of sauropod femurs, calculating the stresses imposed by gravity and increasing body mass when the animals reared up. Their results are published, open access, in the journal of the Palaeontological Society, Palaeontology.
Background^ the two sauropods in the study. Both dinosaurs discussed in the paper were titanosaurs: members of the last great radiation of long-necked sauropods, which dominated many southern continents during the Late Cretaceous. But they were very different animals. Uberabatitan ribeiroi was a very large Brazilian titanosaur from the very end of the Cretaceous, whereas Neuquensaurus australis was a much smaller, more compact saltasaurine from Patagonia. That contrast makes them useful for biomechanical comparison. [1]Their findings are explained in a news item from Agência FAPESP, the official news agency of the São Paulo Research Foundation (FAPESP) in Brazil:
Uberabatitan ribeiroi is known from the Serra da Galga Member of the Marília Formation in Minas Gerais, Brazil, part of the Bauru Group and generally regarded as Maastrichtian in age, so it lived very close to the end-Cretaceous extinction. It has been described as one of the youngest titanosaurs known from the Bauru Basin. Later revision of the material added new anatomical information and refined its diagnosis. In public-facing summaries from Brazilian heritage organisations, it is often described as the largest dinosaur yet found in Brazil, with estimates of around 27 metres in length, though that figure is a popular estimate rather than the central point of the technical description. [2]
Neuquensaurus australis, by contrast, was a small saltasaurine titanosaur from the Anacleto Formation of Patagonia, Argentina, usually dated to the Campanian stage of the Late Cretaceous. Fossils from near Cinco Saltos have made it one of the better-known Patagonian titanosaurs. Unlike the gigantic, more stereotypical sauropods, Neuquensaurus was relatively modest in size and is notable for the presence of osteoderms — bony armour-like scutes in the skin — a feature associated with several of its close relatives. [3]
That difference in build is part of what makes the new study interesting. Neuquensaurus represents a smaller, sturdier saltasaurine body plan, while Uberabatitan represents a much larger titanosaur from Brazil. In the biomechanical modelling, Neuquensaurus and a juvenile Uberabatitan came out as especially capable of sustaining rearing postures, whereas increasing size brought increasing stress on the femur. In other words, these two dinosaurs help show how the same general feeding strategy could become mechanically more costly as sauropods got larger. [4]
South American long-necked dinosaur could easily stand on two legs
Using computational engineering techniques to simulate weight and gravitational stress on sauropod femurs, researchers from Brazil, Germany, and Argentina have demonstrated that these giant quadrupeds could generally remain standing for feeding, mating, and defense.
By André Julião | Agência FAPESP – Sixty-six million years ago, two genera of long-necked, quadrupedal dinosaurs had an advantage over other sauropods: they could easily stand on their hind legs for extended periods. This allowed them to scare off potential predators and feed on leaves high up in trees, for example.
The Brazilian Uberabatitan and the Argentine Neuquensaurus were about the size of a modern elephant. Although they were considered small for their group, it is estimated that adult Uberabatitans could reach 26 meters, making them the largest dinosaurs in Brazil. Because of their size, these sauropods could only stand for extended periods while they were young. This conclusion comes from a study supported by FAPESP and published in the journal Palaeontology. The study was conducted by researchers from Brazil, Germany, and Argentina.
The scientists used a computational technique adopted in engineering. They aimed to estimate the stress on the femur caused by gravity and the weight of the sauropods when standing on their two hind legs.
“Smaller sauropods like these had a bone and muscle structure that allowed them to stand more easily and for longer on their two hind legs. Larger ones were probably also able to stand, but for a shorter time and with less comfort, since the position caused a lot of stress on the femur,” summarizes Julian Silva Júnior, a postdoctoral researcher at the School of Engineering of São Paulo State University (FEIS-UNESP) in Ilha Solteira, Brazil. Silva Júnior is the first author of the study, which was conducted during an internship at the University of Tübingen in Germany with a scholarship from FAPESP.
The researchers digitally reconstructed the femurs of seven sauropods representing different evolutionary lineages, sizes, and anatomical characteristics unique to this group. The digital models were based on fossils found in natural history museum collections around the world.
South Americans
The simulations were performed using finite element analysis (FEA), a computational technique that simulates how materials behave under conditions such as force and heat. This technique is widely used in bridge design, for example.
“Using this technique, we performed two simulations. One dealt with the extrinsic scenario, simulating the force coming from outside to inside. In this case, gravity and the animal’s own weight on the femur when the dinosaur was standing on its hind legs. In the other, we analyzed the intrinsic scenario, the force that the muscles would exert on the femur,” Silva Júnior explains.
The combination of the two scenarios suggests the amount of stress each species endured. The two South American sauropods, a juvenile Uberabatitan ribeiroi (named after the Brazilian municipality of Uberaba, where it was found, and coincidentally, Silva Júnior’s hometown) and Neuquensaurus australis (found near the Neuquén River in Argentina), showed the lowest levels of stress on the femurs. Both species lived during the Late Cretaceous period, about 66 million years ago.
“They had more robust femurs and could dissipate stress better. The bigger ones had very large muscles and even giant femurs, but not enough to support their weight. That doesn’t mean they couldn’t stand up, but they probably chose the best time to do so, because it must have been an uncomfortable position,” says the paleontologist. He points out that adult Uberabatitan individuals, unlike the juvenile analyzed in the study, would probably have had the same difficulty standing on their hind legs as other giant species.
This position would have been useful for feeding and reaching food in the highest parts of trees since sauropods were leaf eaters. It may also have been used for reproduction, allowing males to mount females and perform displays to attract mates. Finally, it may have been useful for defense, making them appear larger to potential predators.
The authors note that the simulations did not take into account the cartilage present in these bones, which could dissipate stress quite efficiently. They also did not consider how the tail would support the animals in the tripodal position.
Furthermore, since cartilage was not examined in any of the seven specimens, it is assumed that its role was similar in all of them. “The tool we use is very efficient for comparisons, even if the answer isn’t exact for each one. By comparing representatives from different lineages, we can get a fairly accurate picture of how these animals behaved millions of years ago,” says the researcher.
Publication:
What this study shows, yet again, is that living things and extinct ones alike are not the products of perfect foresight, but of expedient compromises. Sauropods evolved a body plan that allowed them to dominate the herbivore niche for millions of years, but even that success came with trade-offs. The same long neck and rearing ability that gave them access to food and perhaps advantages in defence or display also imposed increasing mechanical costs as body size grew. That is exactly the sort of messy, contingent outcome evolution produces.
For advocates of Intelligent Design, this creates the usual problem. If these animals were the deliberate products of an all-knowing, all-powerful designer, why give them a useful adaptation that became progressively more stressful and mechanically limiting as they got larger? Why a design that works well enough, but not without cost, compromise and diminishing returns? The answer from evolution is straightforward: natural selection does not engineer perfection; it merely preserves what works better than the alternatives in the here and now.
So, far from pointing to intelligent planning, this research points to the absence of it. It shows a classic evolutionary pattern: a successful adaptation shaped by immediate advantage, constrained by inherited anatomy and physical law, and carrying penalties that no competent engineer would knowingly build in. Sauropods were not designed from scratch by a master planner; they were modified, step by step, from earlier forms, with all the compromises that process inevitably entails.
In other words, this is one more example of reality looking exactly as evolutionary theory says it should, and nothing like the product of a perfect designer. Evolution explains both the advantage and the cost. Intelligent Design can only ignore the cost, excuse it with theology, or pretend that obvious compromise is somehow evidence of perfection.
Advertisement
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
All titles available in paperback, hardcover, ebook for Kindle and audio format.
Prices correct at time of publication. for current prices.
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.