Is the rise of meat-eating dinosaurs complicated?

No.
A Smithsonianmag.com writer is trying to make the ordinary extraordinary by claiming, “The Rise of Meat-Eating Dinosaurs Is More Complicated Than We Thought. “

Figure 1. Herrerasaurus from Black 2020. This is a basal dinosaurs. This is not an omnivore.

Figure 1. Herrerasaurus from Black 2020. This is a basal dinosaurs. This is not an omnivore.

Writer Riley Black (formerly Brian Switek)
writing in smithsonianmag.com declares: “The earliest dinosaurs arose about 235 million years ago during the Middle Triassic. They didn’t look much like modern favorites Triceratops or Spinosaurus. Instead, these lanky creatures didn’t get much bigger than a German shepherd. The current spate of evidence suggests they were omnivorous.”

Black also provides this image (Fig. 1) of middle Triassic Herrerasaurus, the basalmost dinosaur in the large reptile tree (LRT, 1688+ taxa) and this is no omnivore. This taxon is 3 meters or 16 feet long, not the size of a German shepherd.

Black continues:
“Up until now, paleontologists thought theropods remained generally small and on the ecological sidelines from about 235 through 201 million years ago. It was only after a mass extinction at the end of the Triassic, at the 201 million-year mark, that carnivorous dinosaurs started to get big. But that view is starting to change thanks to a new reading of the bone trail by scientists who think large meat-eaters may have appeared much earlier. Virginia Tech paleontologist Christopher Griffin says a key player in this story is Herrerasaurus.”

Confused?  So am I. This brings us back to where the LRT starts, regarding dinosaurs. Everyone in paleo knows Herrerasaurus is a Middle Triassic carnivorous dinosaur. The little German shepherd-sized dinos are either made up or never existed. In either case, Black doesn’t list or illustrate them.

Black continues:
“The known carnivorous dinosaurs during the later part of the Triassic appeared to be smaller and less imposing than the crocodile relatives they lived alongside (such as Postosuchus from the southwestern United States). Thanks to a better understanding of dinosaur growth, however, paleontologists have found that some of those little theropods were hiding a secret.”

Postosuchus is not a crocodile relative in the LRT. Herrerasaurus is closer to crocodiles in the LRT because only crocodylomorphs and dinosaurs make up the clade Archosauria.

Black continues:
“The few remains we’ve found of larger Triassic theropods come exclusively from immature animals that are still growing rapidly,” Griffin says. These young carnivores would have grown to lengths exceeding 18 feet in adulthood. That’s a little less than half a full-grown T. rex, but enough to make you want to avoid meeting such a carnivore face-to-face.”

A few Late Triassic theropod lengths: Tawa is 2m long. Coelophysis is 3m long. Both are represented by adult skeletons. Again, where are these imaginary few remains?

Black finally raises the curtain on her main attraction:
“Late last year, Ludwig-Maximilian University of Munich paleontologist Oliver Rauhut and colleague Diego Pol named an exceptional skeleton of a Middle Jurassic carnivore they called Asfaltovenator. This was a large animal, more than 25 feet long, that approached the average size of the later Allosaurus and bears more a passing resemblance to the later dinosaur.”

This is no big deal. Between the Late Triassic and the Late Jurassic we expect to find theropod dinosaurs bigger than their ancestors and smaller than their descendants with transitional morphologies.

Black concludes with a quote: 
“There is much more to be learned about theropod evolution during this time,” Rauhut says, with finds like Asfaltovenator hinting at what remains to be uncovered.”

Again, no big deal. There is always ‘much more to be learned’ about all taxa ‘during this time.’ Some people complain because I was a journalism major. Sometimes that degree comes in handy.


References
Black R 2020. The Rise of Meat-Eating Dinosaurs Is More Complicated Than We Thought. online here.

re: Traps for Journalists to Avoid

A recent blog by Dr. David Hone entitled Traps for Journalists to Avoid brought up some interesting and valid points. His “tell-tale warning signs” provided some important topics that are worthy of consideration — and others that need to be tempered with an opposing thought or two.

Dr. Hone requested journalist to question their sources, by asking themselves, Is there actually a proper paper? If this story is coming from a conference abstract, grant proposal, self-published manuscript, website etc. then simply leave it be. If this thing cannot get past peer review, or has not tried, it’s not even passed the most basic test of the scientific process. You’re simply asking to be taken in by a nutty idea that has simply slipped, unreviewed, into a conference (and quite possibly sneakily – the content to a talk can be quite different to the title). If there is at least a proper paper in a proper journal that’s a good start.

That’s good advice, generally, but perhaps a bit overstated. Unfortunately, as this blog, The Pterosaur Heresies, have reported time and again, even peer-reviewed published papers sometimes fail to provide valid results. Rather a few promote “nutty ideas.” That’s because everyone has their own little blinders on. Let’s face it, we all suffer from human prejudices and paradigms that push away opposing data. We see what we want to see. Sometimes (hopefully rarely) this occurs in clades of scientists, Their papers get approved by collaborators who also follow bad paradigms, bow to politics, or what have you*. Ideally a manuscript should be sent to one’s harshest critics. Through the hate and vile some truth may appear in those red ink comments. However, the raw emotion and pure negativity can also mask a lack of good opposing evidence. If that’s the case, then a scientist has to move forward. Scientists generally don’t like to have their pet hypotheses “stepped on,” but sometimes that just has to happen…somehow…as a last resort on the web, if all other venues are blocked.

It is not the job of journalists to judge or test published works.
That is the job of other scientists. So how can scientists in the far corners of this planet become aware of novel hypotheses and discoveries unless they are somehow published or promoted? When opposing evidence is prevented from academic publication because the manuscript results overturn the referees’ own hypotheses, then we have something akin to conflict of interest. That happens more than most people realize because its a small world of referees. The ones that are most opposed to certain hypotheses are the ones that are more than happy to referee those manuscripts, to make sure they never get published. Certainly some papers are premature and poorly supported. However, when opposing arguments are inappropriately blackballed then science suffers.

Only when third party scientists are able to test one hypothesis (medicine, method, observation, etc.) against another do we get closer to the truth. So, the basic test of the scientific process is not getting past peer review, as Dr. Hone said. The basic test of the scientific process is to test, test and test again and this can only happen with a free flow of widely available information. Then, whatever made a good paper a century ago or a week ago can quickly become a bad paper when tested against a larger data set or more precise observations. The good papers will float. The bad ones will sink over time.

Dr. Hone also warned against “really odd” results and hypotheses. His solution, “Ask around. And try to avoid regular collaborators of the person in question – their friends might well support them. But if you keep hearing “he said that? really?” then be careful. This might have got through peer-review but no-one seriously buys it.” 

Science Is Not a Popularity Contest
Unfortunately, Dr. Hone is arguing for immediate popular approval, which no novel hypothesis has ever overcome (without the benefit of the passage of time). Everything from feathers on dinosaurs to continental drift has suffered, at first, from their own audacious novelty. The expert are STILL holding on to “pterosaurs are archosaurs,” “wing membranes attach to the ankles,” “modular evolution” and nearly every other “nutty idea” argued against in this blog.

You can’t introduce a discovery without pissing someone else off. Importantly, this “Loyal Opposition” is a good thing IF the arguments and observations are valid. Defending a novel theory is also a good thing. These opposing hypotheses have to be published so this back and forth conversation can begin. Scientists need to be able to put all their cards on the table to see who folds for lack of evidence and support. This may sometimes take more than a lifetime.

There are some paradigms and traditions that just need a good dusting. Others need to be tossed out. When novel hypotheses are newsworthy hopefully journalists will be there to promote them so other scientists have the opportunity to test, test and test again.

*The most common problem I’ve seen is the continuing reliance on small gamut untested inclusion sets in cladistic analysis, a situation remedied here with a large gamut inclusion set.

Your comments are welcome.