When was the Dinosauria named?

Jeff Poling

" Today, in 1841, Richard Owen formally named the Dinosauria."

The above text will appear as part of my entry in The Daily Web Page Calendar, both regular and college editions, on July 30, 1997.

When I was approached by the publisher of the calendar, I struggled to find a date important to the science of dinosaur paleontology. I finally decided on the date of the naming of the Dinosauria. According to Dinosaur!, by David Norman, the date of the naming was a lecture by Sir Richard Owen in Plymouth, England, July 30, 1841. Other publications have given dates of July 30, August 2 or August 24. Since all these dates were within a few days to a month of each other, I was confident I had made a clever public relations coup.

I was an idiot. The light at the end of the tunnel is always the headlight of an oncoming train.

As I discovered from George Olshevsky and Ben Creisler several days after sending in my registration materials, the date of July - August 1841 for the naming of the Dinosauria is one of the most long lived and widespread myths to be propagated in the science. To make matters worse, this myth should have been shot down years ago: the conference at which Sir Richard spoke was well documented and these documents quite clearly show that Owen did not utter the word Dinosauria at his lecture.

Indeed, documents from the time show that he had not yet even formulated the idea of the Dinosauria as a distinct group, let alone created the name.

In 1838, Sir Richard was commissioned by the British Association for the Advancement of Science to study the fossil reptiles of Britain. On August 2, 1841, Owen gave a lecture on the large, terrestrial reptiles whose fossils had been recently found and Owen had been studying as part of his commission. In this lecture, Owen grouped the three animals represented by these fossils, named Iguanodon, Megalosaurus and Hylaeosaurus, into the Lacertian or Squamate division of Class Reptilia. Basically, he considered them to be huge lizards.

During the next several months, as he prepared the final draft of his commissioned report, Owen continued to study the fossils available at that time, including new specimens that had been unavailable before his lecture in 1841. From these fossils Owen discovered that the sacral vertebrae of Iguanodon were fused together just as they were in Megalosaurus. This condition, which was unique to these animals, convinced Owen that these animals were closely related to each other, but not closely related to extant reptiles, including the lizards that he previously had grouped them with. Owen concluded that these were a heretofore unknown type of reptile, and erected a new group specifically for these reptiles. He named the group the Dinosauria.

Sir Richard's final report on British reptiles was very different from the lecture given on the subject in 1841. It recognized Iguanodon, Megalosaurus and Hylaeosaurus as members of a new group of reptiles, the Dinosauria.

This report was published in April, 1842. This is the true date for the naming of the Dinosauria.

1. Norman, David. 1991. Dinosaur! New York: Prentice Hall.
2. Torrens, Hugh. When did the dinosaur get its name? New Scientist (4 April 1992): 40-44.