The Dinosaur Renaissance
-Chrissie
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Dinosaur and other megafauna bones are reported in one form or another throughout written history. They likely inspired mythical stories about giants and characters like the Cyclops. Dinosaurs as we think of them aren’t really a thing until the nineteenth century, following an increase of finds and study. The term “dinosaur” was coined by English geologist Sir Richard Owen in 1841. It means, as any five-year-old can tell you, “Terrible Lizard.”
Dinosaur paleontology in the mid- to late-nineteenth century saw them as active and agile creatures. Some, most prominently Thomas Henry Huxley, wrote about the similarities between birds and dinosaurs. This connection was lost, however, with the 1923 publication of The Origin of Birds by Gerhard Heilmann. He specifically rejected the connection based on the lack of a furcula (wishbone) in dinosaurs. This pushed them firmly into the lizard camp, with all of the assumptions about cold-bloodedness and reptilian functioning left intact. Dinosaurs came to be thought as great lumbering beasts who could barely hold themselves up. The small brain cavities in the few intact skulls found indicated to the scientists of the era that they must be unintelligent. Large sauropods were often depicted in lakes or swamps with the idea that they required the water’s buoyancy to stay upright. And, being cold-blooded and lizard-like, they were believed to drag their tails, and so dinosaur skeletons were reconstructed to show dragging tails; it was beside the point that some of the vertebrae had to be fitted incorrectly or even broken to achieve that posture.
Even while this was the standard, one animal stood out to bridge the gap: Archaeopteryx. It had unquestionably reptilian features alongside avian ones, as well as impressions of feathers in the stone surrounding the fossilized skeleton. It has long been considered the first bird, but also grouped with dinosaurs. And it did serve as a connector. In 1964, Dr. John Ostrom unearthed the first specimen of Deinonychus, a dinosaur with unquestionably bird-like qualities. He published his argument connecting dinosaurs and birds in The Quarterly Review of Biology a decade later.[1] He made a point of validating Huxley’s connection between dinosaurs and birds. Ostrom laid the groundwork but it was one of his graduate students, Robert T. Bakker, who made it famous.
Dr. Bakker published both scientifically and popularly, most notably with his 1986 book The Dinosaur Heresies. Bakker became a regular on science shows on PBS and the new Discovery Channel cable network talking about the connections between dinosaurs and birds; he even once appeared on the Tonight Show. He was immediately recognizable with his long hair and beard and cowboy hat. He was one of Michael Crichton’s inspirations for Dr. Alan Grant in his novel Jurassic Park. It was Dr. Bakker who named this era as the Dinosaur Renaissance.[2]
One of the other models for Dr. Grant is the other big name in the dinosaur renaissance: Dr. John Horner. He is, perhaps, best known as the paleontology consultant for the movie Jurassic Park, but his work on dinosaur behavior is incredibly important in the field. It was Dr. Horner who determined that dinosaurs did indeed socialize in family groups and care for their young. He began this work with excavations of a nesting area in which some of the eggs held embryos and were surrounded by adults of the species, which he named Maiasaura, meaning “Good Mother Lizard.”
The last major change of the dinosaur renaissance was the issue of their extinction. Until the late 20th century it was believed that dinosaurs died out because they were simply unfit in comparison to the up-and-coming mammal species. But, in 1978, Luis and Walter Alvarez, a father-son team of a physicist and geologist, researched a layer of iridium in the sedimentary rock dating to about 66 million years ago. This layer indicated a massive impact from a meteor or other extraterrestrial object because it was found everywhere in the world. In order for such a layer to be created, the impact would have needed to throw a great deal of material into the atmosphere, causing years of changed weather patterns and disrupting the food chain. The timing, coincident with the mass extinction at the end of the Cretaceous period gave a reason for the extinction. The Chicxulub Crater was discovered at about the same time and was soon correlated to the iridium layer. This is the generally accepted reasoning for the deaths of the non-avian dinosaurs, though a few other theories exist.
The work of Drs. Ostrom, Bakker, Horner, and others inspired a new generation of paleontologists with whom the work of the Dinosaur Renaissance is flourishing.
[1] Ostrom, John, “Archaeopteryx and the Origin of Flight,” Quarterly Review of Biology 49, no. 1. (1974).
https://www.journals.uchicago.edu/doi/abs/10.1086/407902
[2] https://tuda.triumf.ca/evolution/articles/scientificamerican0475-58.pdf