Scientists Retract Dino-Bird Paper
Was it a Bird or a Dinosaur? The Latest Guess is Neither. It was a Lizard!
Another Example of Guesswork in Paleontology
by Jerry Bergman, PhD
A recent fossil find preserved in amber looked a lot like a bird, but a Nature headline proclaimed it to be a dinosaur.[1] It has now been determined to be a lizard! Its final classification can be debated, but it cannot be debated that it is a good story which illustrates the degree of guesswork in the field of paleontology. As is often said about the weather, if you don’t like it, wait for a day or so and it will change. Sometimes the same is true about the confident claims in science news. Mark Twain joked that Brontosaurus consisted of “nine bones and six hundred barrels of plaster of Paris.” One of the many examples that documents this problem of over-eager speculation is the following story.
A New Discovery Baffles Scientists
The story begins with all the science news outlets announcing a spectacular discovery: a 99-million-year-old bird-like skull entombed in amber. The fossil even had preserved soft tissue associated with the skull and the remains of the animal’s long tongue.
Amber entombs mostly insects, but occasionally small animals—and even the bones of larger animals—are preserved by the sticky tree resin. The find revealed a new body plan that was first claimed to be part of a tiny new dinosaur species. (How they determined it was a dinosaur was not clear from the write-up, but a later evaluation of the fossil forced the article’s formal retraction; see below.) The supplied artwork gave it a very bird-like appearance, with feathers and all, but everyone called it a dinosaur.
The original article was published on March 11, 2020 in one of the most prestigious science magazines on Earth, Nature, founded on November 4, 1869. One of Nature’s early supporters was biologist Thomas Henry Huxley, a heavyweight of Victorian science and a staunch ally of Charles Darwin (so was John Tyndall; see yesterday’s entry). Huxley was known as ‘Darwin’s bulldog’. The magazine was a pro-Darwin venue from the beginning and tended to focus on publishing articles that supported Darwinism. The article reviewed here is no exception, although no connection to evolution was noted in the original paper.
Eventually, the evidence against the original dinosaur designation was so overwhelming that the article was retracted four months later. It’s hard to say how many readers who had been influenced by the original paper noticed the retraction.
The Fossil
The find consisted of an comparatively well-preserved tiny skull 15 millimeters in length, about the same size as the diameter of a U.S. penny. No other body parts were discovered. The find would have been the smallest known dinosaur, rivaling even the tiny bee hummingbird (Mellisuga helenae), the smallest known living bird.[4] This fact alone should have raised questions about its identity. Nonetheless, paleontologists decided that it is a totally new species of bird-like dinosaur, which they named Oculudentavis khaungraae. Additional artwork showed it flying around with flapping wings, perching feet and a tail. Such is the eagerness by evolutionists to link birds to dinosaurs.
Analysis of the skeletal features suggest the tiny creature, whatever it was, represented a mature animal. It had comparatively big eyes, and a mouth full of tiny teeth. The creature’s eyes would have bulged out of its head in a manner not seen in any other living animal, making it hard to understand exactly how the eyes functioned. The reinforced skull also is evidence that it had a stronger bite than similar-sized species, and likely fed on small insects. These traits were behind the original genus name “Oculudentavis” derived from the Latin for “eye-teeth-bird.” Its species name honors the person responsible for donating the specimen for research.
To study the skull in detail, the team used a specialized scanner able to image features as small as a millimeter to generate a detailed 3-D reconstruction. The retraction was also based on further evaluation of the computed tomography (CT) scans. Critics noted
several features of the animal that contradicted the idea of a bird-like dinosaur and … that it aligned much better with lizard traits. These included features of the animal’s lizard-like teeth and the features on its fenestra, or the openings in the skull behind the eye sockets that are found in animals such as dinosaurs and lizards.[5]
The researchers added that the skeleton provides “unprecedented insights into the soft tissue and skeletal anatomy of minute fauna, which are not typically preserved in other depositional environments.”[6] No claims were made that the find lent credence to some evolutionary scenario. Rather, the claim was that the “size and morphology of this species suggest a previously unknown bauplan [German for blueprint], and a previously undetected ecology.”[7]
A bauplan is a set of morphological features common to many members of a phylum, such as the vertebrate body plan, which consists of many phyla. Thus, the find indicates an entirely new body design. That is one reason so much difficulty existed in its classification, which ultimately resulted in the retraction.[8] The reasons for this conclusion include the animal’s eye structure which is very different than that of all known birds.
The Retraction
What is it, really? The latest guess is that it was a weird lizard with a bird-shaped head. The reason given for the retraction was that while
the description of Oculudentavis khaungraae remains accurate, a new unpublished specimen casts doubts upon our hypothesis regarding the phylogenetic position of HPG-15-3.[3]
Actually, there was no evidence supporting the creature’s “phylogenetic” (i.e., evolutionary) position. The claim that this was a bird-like dinosaur was retracted July 22, over four months later.
When the paper was published, many mainstream publications were intrigued by the story and wrote about the findings, giving the team from China, the U.S. and Canada a bit of notoriety. But shortly thereafter, others in the field began questioning the categorization of the fossil—many suggested it appeared to be a lizard, which is a different group of reptiles from the dinosaurs.[2]
An important reason for rejecting its original classification is that the animal’s eye structure was very different from that of all known birds. Birds have a ring of bones, called the sclerotic ring, comprised of scleral ossicles, which are simple and fairly square bones designed to support the eye. The sclerotic ring bones of Oculudentavis, by contrast, are spoon-shaped – a trait only found in a few living lizards. The eye’s orbital bone-cone is similar to the owl-eye orbit bones, indicating that the animal had exceptional vision as do owls. Conversely, unlike owls, the eyes faced sideways and the ossicles’ opening was very narrow, restricting the amount of light entering the eye. This is evidence that Oculudentavis was active during the daytime.[9]
Conclusions
Given that only the skull and beak were found, the researchers were able to glean a fair amount of data and make some early determinations. However, as it turned out, some of their major conclusions were premature. The fact that only the head was found clearly should have signaled caution in its classification, but it did not – even though some of the world’s leading paleontologists were listed as authors of the study.
This case should indicate that trained and tempered taxonomy takes time. No doubt, more forthcoming examples will be discovered that will help fill in some blanks about this new creature. On a positive note, the story highlights the potential of amber deposits to reveal the lowest limits of vertebrate body size. This recent finding, with its soft tissue preservation that defies its assigned 99-million-year date, also illustrates the fact that amber is an incredible window to the past. Inevitably, in the end, the facts contradict evolution and support creation.
References
[1] Xing, Lida; Jingmai K. O’Connor, Lars Schmitz, Luis M. Chiappe, Ryan C. McKellar, Qiru Yi & Gang Li. 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature 579:245–249, March 11.
[2] Yirka, Bob. 2020. Paper describing hummingbird-sized dinosaur retracted. https://phys.org/news/2020-07-paper-hummingbird-sized-dinosaur-retracted.html.
[3] Xing, et al. 2020. Retraction Note: Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature, July 22. https://www.nature.com/articles/s41586-020-2553-9.
4 Geggel, Laura. 2020. Hummingbird-size dinosaur may actually be a lizard. LiveScience. July 20. https://www.livescience.com/retraction-smallest-dinosaur.html.
6 Geggel, 2020. [Internal citations #6, #7, #8 are all cited on the next page.]
7 Geggel, 2020.
8 Rincon, Paul. 2020. Smallest dinosaur found ‘trapped in amber’. BBC News, March 11. https://www.bbc.com/news/science-environment-51835946.
Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.