Modern-day paleo myths: Dinosaurs as lizards

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In this day and age there are no shortage of books, websites, and videos dedicated to debunking classic paleo myths. The majority of this mythbusting focuses on myths about dinosaurs. As the poster children for paleontology, this isn’t that surprising. With so many takes on this subject it comes as no surprise that all of the classic dinosaur myths have long since been debunked, such as dinosaurs as low-energy tail draggers, walking around like Godzilla, being evolutionary failures, inferiority to mammals, being pee brained monsters, etc.

However, as quickly as these classic dinosaur myths have been eradicated, new ones have come and taken their place. These myths/misconceptions are routinely cited today without any question despite being just as erroneous as the myths that preceded them.

This is the start of a new series I want to cover on the site: dispelling modern myths in vertebrate paleontology. Given the bent of my website, these myths/misconceptions will largely stay focused on reptile-related animals, though I am open to taking the occasional foray into other animal groups if the myths are egregious enough (which is to say that suggestions are welcomed).

The seminal installment for this series is one that I see mentioned time and again:

“Dinosaurs were once thought of as big lizards.”

Did early researchers think that dinosaurs were lizards?

One doesn’t have to look far to see this statement pop up. In fact, it can often be found used as a counter argument to some classic dinosaur myths. The argument typically goes that early dinosaur researchers—Sir Richard Owen in particular—thought of dinosaurs as just a type of lizard.

The argument for this is and always has been a weak one. Certainly early researchers turned to lizards as models for dinosaurs, but never with the assumption that dinosaurs were a type of lizard. Lizards were just one of many modern-day analogues used to study dinosaurs. Early researchers also looked at crocodylians, and turtles (not so much with snakes, but I suppose there are obvious reasons for that). It was clear from the beginning that dinosaurs were doing things differently from “typical” lizards. As Owen (1842) wrote [emphasis mine]:

This group…is characterized by a large sacrum composed of five ankylosed vertebrae of unusual construction, by the height and breadth and outward sculpturing of the neural arch of the dorsal vertebrae, by the twofold articulation of the ribs to the vertebrae…by broad and sometimes complicated coracoids and long and slender clavicles, whereby Crocodilian characters of the vertebral column are combined with a Lacertian type of the pectoral arch…The bones of the extremities are of large proportional size, for Saurians; they are provided with large medullary cavities, and with well developed and unusual processes, and are terminated by metacarpal, metatarsal and phalangeal bones, which, with the exception of the ungual phalanges, more or less resemble those of the heavy pachydermal Mammals, and attest, with the hollow long-bones, the terrestrial habits of the species.

The combination of such characters, some, as the sacral ones, altogether peculiar among Reptiles, others borrowed, as it were, from groups now distinct from each other, and all manifested by creatures far surpassing in size the largest of existing reptiles, will, it is presumed, be deemed sufficient ground for establishing a distinct tribe or sub-order of Saurian Reptiles, for which I would propose the name of Dinosauria.

The infamous sprawling Diplodocus image by Hay 1910
The infamous sprawling Diplodocus image by Hay 1910

Often, when I hear this statement about dinosaurs being viewed as giant lizards, it is usually followed by the now infamous image of a sprawling Diplodocus carnegii, by Oliver Hay (1910). While it was true that Hay proposed a more “traditionally” reptilian view of sauropods (Hay 1908, 1910), it should be noted that he thought this only for sauropods.

Before exact knowledge of these reptiles had been gained, it was known that the dinosaurs of the other groups, herbivorous and carnivorous, walked erect, after the manner of birds. — Hay 1908

Hay’s argument was not that D. carnegii was a sprawler because it was a reptile, but rather because it was so huge. Hay had trouble envisioning how such a huge, semi-aquatic (at the time) animal could have possibly hauled itself up on land.

It’s important to note that Hay’s hypothesis was a minority for its time, with the only real support coming from Gustav Tornier (1909). This hypothesis was also quickly dismantled in 1910 by William J. Holland.

Owen’s Terrible Lizards

Perhaps the most damning part of this myth, and ultimately the one that pushed it forwards, was Sir Richard Owen’s original name for the group.

Coined in 1841 at the 11th Meeting of British Fossil Reptiles (transcribed and published a year later), Owen infamously named this group of large-bodied reptiles: Dinosauria; the terrible lizards.


Gr. δεινός [deinos], fearfully great ; σαῦρος [sauros], a lizard.  ln the tabular arrangement of extinct
Saurians founded by M. Herm. v. Meyer on the development of their organs of motion, theMegalosaurus and Iguanodon are grouped together in Section B, with the following character :—Saurians with locomotive extremities like those of the bulky terrestrial Mammals… — Owen 1842

As can be seen from Owen’s writing, the term “terrible” never really popped up. The Greek deinos can be translated as terrible (if used as an adjective), but Owen used it in the superlative form so as to evoke a sense of these animals’ immense size (Farlow and Brett-Surman 2012).

Okay, so Owen called them the “fearfully great lizards”, right?

Well, no.

Although Owen used the Greek sauros, he never meant it to mean lizard. This was evident by his wording throughout the rest of the British Fossil Reptiles meeting (Owen 1842). In Owen’s mind, dinosaurs were saurians, but saurians were not lizards. Rather, saurians were an order within the class Reptilia, that could be broken up into the following four suborders:

  1. Enaliosauria — Ichthyosaurs, Plesiosaurs, and kin
  2. Loricata — Crocodylians
  3. Lacertilia — Lizards
  4. Pterydactyla — Pterosaurs

Later, when Owen coined the term: Dinosaur, it became the fifth suborder of Sauria (Torrens, 2012).

Note that snakes (Ophidia) and turtles (Chelonia) were both viewed as separate orders of reptiles by Owen.

This separation is all the more important given that Owen was a staunch creationist. Yet despite not believing that animals evolve, he knew that dinosaurs didn’t fit in with his “lacertians”, and were a unique group unto themselves.

Interestingly, Gideon Mantell, the English obstetrician/paleontologist famous for discovering Iguanodon, did lump dinosaurs in as lizards, but it would be unfair to assume that he thought all dinosaurs were lizards, for as Torrens (2012) points out, Mantell didn’t realize that the animals he found were a unique group until well after the term Dinosauria, was coined. Famed paleontologist Herman von Meyer, was more on the ball with this and did attempt to place dinosaurs in a unique group unto themselves,  Pachypodes (von Meyer 1845) or the “heavy-footed saurians”, but he was late to the game by three years (Torrens 2012).

Why the confusion

The wandering definition of Sauria

Though mostly touched on above, the main confusion behind this myth stems from the Greek suffix: sauros. In ancient Greece, this word may well have been the common way of talking about the local lizard fauna, but in the scientific realm, the term took on a completely different meaning. Sauria was coined in 1802, by anatomist James Macartney (often misspelled as McCartney) in a foreword to Georges Cuvier’s book on comparative anatomy. Macartney was asked to present a table of “modern” taxonomy. At the time, the French term “Sauriens” was used rather unofficially as a term that included lizards, crocodylians and salamanders. Macartney Latinized this French term, producing Sauria.

Etymologically, the trek of Sauria is rather interesting. It started off with the Greek sauros. Like most Greek words, it was transcribed into Latin as Rome took over the region. Thus sauros became saurianus. As Latin split off to form the multiple Romance languages, one of those languages—French—bastardized saurianus into saurien. Then, as science made ancient Greek and Latin the language of choice for communication, the now French word was re-transcribed into Latin, becoming the now well known word, Sauria.

Etymology aside, Macartney’s contribution to taxonomy was the lumping (or in his case, refining) of the group formerly known as Sauriens, to include only crocodylians and lizards in the new order: Sauria. Over the past century, the definition of the term has changed to reflect different views on reptile taxonomy at the time, with many early workers popping crocodylians out of Sauria in an attempt to have the name reflect lizards only (Lacertilia). This changed in 1984 when Jacques Gauthier gave a thorough reevaluation of this reptile group, and pushed to reinstate Macartney’s original definition, making Sauria a clade that included Archosauria and Lepidosauria (Gauthier 1984, Gauthier et al. 1988).

The point being that the scientific name, Sauria, was never meant to mean lizards. Lizards were just a type of saurian. This is true today and, more importantly, it was true back in Owen’s day when he first named Dinosaurs.

In truth, the best translation of Sauria would be: a reptile. Which means that when dinosaurs were originally named by Owen on that fateful day in in 1841, they were the fearfully great reptiles, not the “terrible lizards”. This translation holds for practically all taxonomic names that use a variant of sauros.

  • Tyrannosaurus= Tyrant Reptile
  • Pterosaur = Winged Reptile
  • Hadrosaur = Bulky Reptile
  • Plesiosaurus = Near Reptile
  • Mosasaurus = Meuse River Reptile
  • Hydrosaurus = Water Reptile

So to conclude, early paleontologists were pretty certain that dinosaurs were related to lizards, but barring one or two outliers, they never really thought that dinosaurs were a kind of lizard.



Farlow, J.O., Brett-Surman, M.K. 2012. The Complete Dinosaur. Bloomington IN. Indiana University Press. p:ix.

Gauthier, J. 1984. A Cladistic Analysis of the Higher Systematic Categories of the Diapsida [Dissertation]. Berkeley. U California.

Gauthier, J., Estes, R., de Queiroz, K. 1988. “A Phylogenetic Analysis of Lepidosauromorpha.” in Estes, R., Pregill, G. (eds). The Phylogenetic Relationships of the Lizard Families. Palo Alto, CA. Standford U Press. pp:15–98.

Hay, O. 1908. On the Habits and the Pose of the Sauropodous Dinosaurs, Especially of Diplodocus. Am. Nat. 42(502):672–681.

Hay. O. 1910. On the Manner of Locomotion of the Dinosaurs, Expecially Diplodocus, with Remarks on the Origin of the Birds. Proc. Wash. A. Sci. 12(1):1–25.

Holland, W.J. 1910. A Review of Some Recent Criticism of the Restorations of Sauropod Dinosaurs Existing in the Museums of the United States, with Special Reference to that of Diplodocus carnegiei in the Carnegie Museum. Am. Nat. 44(521):259–283.

Owen, R. 1842. Report on British Fossil Reptiles. Part II. in Murray, J. (ed). Report of the 11th Meeting of the British Association for the Advancement of Science. London, UK. Albermarle Street. pp:60–204.

Macartney, J. 1802. Preface and Table III. in Cuvier, G. (ed). Lectures on Comparative Anatomy. Translated by W. Ross. Oriental Press, Wilson and Co. for T. N. Longman and O. Rees, Paternoster Row.

von Meyer, H. 1845. System der fossilen Saurier. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde. 1845:278-285.

Torrens, H. 2012. “Politics and Paleontology: Richard Owen and the Invention of Dinosaurs.” in Farlow, J.O., Brett-Surman, M.K. (eds). The Complete Dinosaur. Bloomington, IN. Indiana University Press. pp:25–44.

Tornier, G. 1909. “Wie war der Diplodocus carnegii wirklich gebaut?”, Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin 1909-4:193-209.


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2 Responses to Modern-day paleo myths: Dinosaurs as lizards

  1. Avatar Deltadromeus
    Deltadromeus says:

    It’s sad that these days, people don’t want to call dinosaurs reptiles, particularly in the online dinosaur fan circles (just like how said circles tend to think all dinosaurs had feathers to some extent, in the face of evidence suggesting otherwise). Some have even gone so far as to suggest an entirely new name for dinosaurs.

    It reminds me of a post on a website I came across where someone referred to Kentrosaurus as (and I use their exact spelling) “the pointiest birb”.

  2. Avatar Joao S. Lopes
    Joao S. Lopes says:

    There’s no Romance *saurianus. Greek sauros was not adopted in Latin and didn’t survive in vulgar languages until its use in scientific vocabulary. Sauria is the plural of a neuter Latinized “saurium” derived from Greek sauros with an arbitrary new suffix.