December 4th

Box #4 in our count down is Heterodontosaurus…

Heterodontosaurus: the “Different Toothed Lizard”

Heterodontosaurus was a turkey-sized dinosaur from early Jurassic South Africa, which was a harsh, dry place to live. A hard beak and three different kinds of teeth helped it chew hard, srubby plants and insects. There were small cone teeth just behind the beak, followed by large, tusk-like canines, and the rear teeth were like hard chisels. The tusks were straight, partially serrated, and the bottom ones were longer than the canines on top. They may have used them when fighting with each other, like tusked deer do today.

Yes, some small deer have tusks! These are not like the curved tusks of elephants or wild pigs. Unlike many illustrations of Heterodontosaurus, it is likely that only the tips might have been visible in life. Something to be shown in an open-mouthed challenge of aggression, like a dog baring its teeth. When not used for challenges between each other, either for show or for actual fighting, the tusks surely would have other uses. Perhaps Heterodontosaurus marked territory by scraping its tusks against the bark of plants? Or perhaps they were useful for breaking twigs or other tough plants as they chewed?

Many modern illustrations show Heterodontosaurus a bit like nimble, two-legged porcupines. Including mine. This is because of a relative called Tianyulong, which preserves long filaments like bristles from its neck to its tail. With this lovely fossil, combined with other small herbivorous dinosaurs also preserving filaments and various levels of fluff, then it is very likely that Heterodontosaurus was also in the rank of fuzzy dinos.

There is also a possibility of their use of burrows. Even though Heterodontosaurus did not have any specific adaptations for digging, we do see a few other small, bipedal herbivores buried in their own burrows. Many small animals take advantage of already existing burrows, especially in desert environments, so Heterodontosaurus’ small size makes it well suited to taking advantage of someone else’s hard work once the owners move out.

6 thoughts on “December 4th

  1. I like the color pattern that you chose for this species. I’m also musing on the image of a pair of males staring each other down, raising the hackles of their filaments to puff themselves up, and viciously snarling and bearing their fangs like a pair of angry baboons.

    Liked by 1 person

  2. I must say, Heterodontosaurus is becoming more special and interesting as we uncover more ornithischians. Good job with your presentation, Mrs. Patricia.
    For today, my advent selection is Eunotosaurus, a Permian reptile found in southern Africa. It is thought to be a close relative of turtles and had widened ribs that were somewhat akin to turtle shells. Named in 1892, it wasn’t until 1914 that it was proposed to be an ancestor to turtles. The gap of turtles would then take many years to fill, but the discoveries of Odontochelys, Pappochelys, and Eorhynchochelys provided closures to said gaps. It should be mentioned, however, that Eunotosaurus’s wide ribs could have evolved independently and that it has been suggested that it may have instead been a parareptile a neodiapsid unrelated to turtles, or even a synapsid.


    1. I don’t know when you’ll read this, but in addition to what I said, you kinda already spoiled the fifth critter on the DinoToyBlog forum. We shan’t discuss it for now, though.
      P.S. I want to know what you have to say about Eunotosaurus and the information about it that I presented.


      1. Hi Angel, thank you for sharing. Eunotosaurus is a really cool critter, and turtle or no, it’s a neat example of critters with traits that may have developed into the turtles we see today.

        I’m glad you like my Heterodontosaurus 🙂


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