When I first learned about the prehistoric (mega)fauna that we now commonly call non-avian dinosaurs they where just referred to as dinosaur. I am trying to figure out when we made the collective switch in articles and literature to the use of "non-avian dinosaur".

Merriam-Webster provides us with a definition and indicates that the first known use is in 1988. But that does not indicate it was in common use nor general knowledge that birds are a descendant of dinosaurs which means we need to distinguish between avian and non-avian dinosaurs.

So can someone help me find when the trend to the more specific non-avian dinosaurs got started?

  • $\begingroup$ Don’t you mean when did it become common knowledge that birds are NOT the descendants of dinosaurs? People used to think they were so, and this was the mistake that occasioned the invention of the term you reference. It depends when you started reading Robert Bakker's explorations of dinosaur endothermy starting in 1968. Most of the dinosaurs — both the avian ones and the non-avians ones — went extinct at the K-Pg boundary. Most dinobirds died then and only one tiny branch of them survived: the little, ground-not-tree-dwelling but flighted toothless ones with beaks for cracking open seeds. $\endgroup$
    – tchrist
    Jun 6 at 1:22
  • $\begingroup$ Is this specific to academic texts in biology and/or paleontology? If so, you might be better asking biologists or paleontologists. $\endgroup$
    – Stuart F
    Jun 6 at 1:26
  • $\begingroup$ @tchrist ?? Of all the life that survived the KT event, only birds are descended from dinosaurs. Doubt they ate seeds, termites are more likely. It's believed that all mammals that survived were insectivores. $\endgroup$
    – Phil Sweet
    Jun 6 at 2:06
  • $\begingroup$ @PhilSweet Birds are a kind of dinosaur in the same way that humans are a kind of great ape. That's different from saying something like reptiles are descended from amphibians. $\endgroup$
    – tchrist
    Jun 6 at 2:09
  • $\begingroup$ The term non-avian dinosaur is usually taken to be a term used in chronological classification schemes. There are three systems of classification that share some terminology and supplement as needed with unique terms. You can base all branching on the known fossil record. Or you can base some of it on hypothetical lineages, Or you can look at timelines and dateable events and use terms that relate to specific chronology. Non-avian dinosaur basically belongs to the third system. $\endgroup$
    – Phil Sweet
    Jun 6 at 2:17

1 Answer 1


Here is what Google Ngrams has:

Google ngram plot of "non-avian dinosaur"

This suggests that the mid-70's are the first recorded instance, but it wasn't until the 90's that it began to gain use. What defines "common use" is up to you.

  • 2
    $\begingroup$ The understanding that bird are dinosaurs was not a sudden realization but a slow accumulation of evidence and convincing scientists along with the rise of cladistics and phylogenetics making such clarification useful. so this is probably the best answer you can get. $\endgroup$
    – John
    Jun 7 at 22:41

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