Now here’s a new one for the blog, and another dinosaur I had never heard of until Mattel made a toy of one… Guaibasaurus. Guaibasaurus is a genus of basal saurischian from the Late Triassic Caturrita Formation, in southern Brazil. It was described in 1999 by José Bonaparte and was classified as a basal theropod. Some recent cladistic analyses place it as a basal sauropodomorph but its exact classification is still unknown. There seems to be more support in the sauropodomorph camp. Guaibasaurus is known from a few mostly complete post-cranial skeletons including one that’s assuming a resting posture like that of birds, with the hindlimbs tucked under the body, arms flexed to the sides, and what little bit of the neck there is curved leftwards.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_1.jpg)
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_2.jpg)
To uncover why Mattel would produce such an obscure animal for the Jurassic World line I visited the Guaibasaurus page on the Jurassic Park Wiki. I discovered that Guaibasaurus was featured on the Jurassic Park Institute’s Dinopedia, an online dinosaur database from the early 2000’s that’s now shut down. It featured an illustration by Timothy Bradley of Guaibasaurus reconstructed as a theropod. It makes me wonder if that old website is ever a source of inspiration for the folks at Mattel. While the toy is not identical to Timothy Bradley’s illustration it is still clearly theropod-inspired.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_6.jpg)
Mattel’s Guaibasaurus stands 3” tall at the hips and measures about 7.5” long. Size estimates for Guaibasaurus range from 6.6-10’ (2-3 meters). The toy comes out to be 1/16 in scale when scaled down from the 10’ estimate. Of course, without a head and neck who can say for sure how long the animal was? Some reconstructions give it a short neck, and others a long one.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_7.jpg)
The head and neck have to be speculative but there’s no post-cranial accuracy here either. The torso is too short and compact and there’s nothing about the toy that mirrors the skeleton of Guaibasaurus or basal saurischians in general. Mattel could have labeled it a Coelophysis, Sinosaurus, or any number of small lithe theropods and it would still be wrong but no more or less than it already is. The hands aren’t pronated though, so that’s something.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_3.jpg)
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_5.jpg)
The action feature is utilized by pushing the body down against the hindlimbs, which raises and lowers the neck and opens and closes the mouth. The arms are on ball joints and can swing in-and-out. The tail rotates too.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_4.jpg)
Despite really being a Guaibasaurus in name only this is an attractive little toy that’s serves well as a generic small theropod. It has a shallow crest over each of the nasal bones and I’m a sucker for crested theropods. There are also twin rows of spines running down the back of the head and neck. The toy is covered in fine pebbly scales with scutes running down the fingers and toes. The rib cage is slightly visible under the skin and the legs are nicely muscled.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_8.jpg)
The teeth are large and blunt, and the toy has the same unsightly overbite as oh so many other Mattel theropods. These are unattractive features, especially since Mattel has demonstrated that they can do better. The back of the lower jaw isn’t flush with the upper jaw which makes the internal jaw musculature visible much further back than it should be. The tail is also too short, and the feet are too large. These are all things that Mattel collectors are used to though.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_11.jpg)
The paintjob is one of the toy’s biggest draws, at least for me. The body is an attractive shade of dark green while the head, neck, and lower legs are black. The lower jaw is white and connects to a white slash running through the neck and torso, with black edging around it. I enjoy this color combination and the contrast it creates. The teeth are white, tongue pink, and the claws are unpainted. The yellow eyes are quite striking against the black cranium.
![](https://dinotoyblog.com/wp-content/uploads/2024/06/Guaibasaurus_Mattel_9.jpg)
Overall, this toy doesn’t make for a great Guaibasaurus but I do like that it gets the name out there. It’s decent for a cheap toy theropod however and features like the crests, spines, and paintjob give it some appeal. It’s also a Triassic dinosaur and that always piques my interest. The Mattel Guaibasaurus is currently available but was difficult for me to track down, stay vigilant dino hunters!
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Hi Gwangi,
I’m loving all the dinosaur toy reviews you’re writing, the level of detail and research you do is amazing! Is it possible for me to get a contact email address for a toy review opportunity? you can contact me at [email protected]
Thanks! If you pull down the tab on the top of the page there’s a Submit Review link that you can use.
Thanks! I’ve sent an email through the link, hopefully it will find its way to you soon 🙂
*Just a clarification, I don’t want to write a review, I’m actually interested in sending you a PR package of dinosaur toys.
Thanks for the clarification, I assumed to wanted to submit a review! I looked up your email and see that you work for ToyMonster. I’ve reviewed a few Captivz toys on this blog and plan to do more in the future. Love them! Exited to hear more about your PR package.
The email you sent won’t go to me personally, it will go to the blog owner. I don’t own the site, I just write for it.
Someone on the DTF once suggested, in jest of course, that Mattel creates designs/sculpts first, and then pulls a name out of a hat and assigns it to a figure. This toy reminded me of that comment.
I remember reading that. Jest or not, they might be onto something!
Back in August of 2023, when a post on this blog showcased the Guaibasaurus, I brought up how it could be interpreted as a herrerasaurid based on older classification interpretations. Now that I’ve done more research, I meant to say “theropod”/the term “theropod” makes more sense. I still would prefer it is this figure looked more like a sauropodomorph, but at least given its debated classification as of now, I don’t think this sculpt/design is a dealbreaker for me. Anyhow, I appreciate there being even more figures of Triassic fauna from Mattel.