THEROPOD LIPS: the PNSO case

The recently released Yangchuanosaurus and Saurophaganax models spawn some interesting thinking about PNSO’s philosophy.

A few words about the “lips debate”.

If in 2017 the analysis of the facial bones of a Daspletosaurus skull led to the hypothesis of exposed teeth like crocodiles, the extraction of the fossil tooth of another Daspletosaurus revealed an interesting detail: both the internal and external surfaces show no signs of dehydration and weakening of the enamel. This would contrast with what has been observed in crocodile teeth, whose external surface often appears cracked.
Furthermore, tyrannosaurids changed teeth at a much slower rate than crocodiles, so a tooth that has not been replaced for a long time wouldn’t have been able to maintain perfect enamel without adequate coverage. The 2023 study uses this and other analyses to thus suggest the presence of lips in T. rex & co.

Many think Cullen et al.’s paper puts an end to every discussion. Still, we should all remember that their proposal is not written in stone, even though it is highly valid, and some people in the field, paleontologists included, may not be convinced. Also, the whole “Jurassic Park was wrong” thing mentioned in the press releases is not that solid since T. rex too has lips and gums: yes, the teeth are exposed, but it’s not so different from what we usually see in Smilodon paleoart, while Carr’s paper proposes a crocodile-like facial sensory system.

Jurassic Park features three theropods with teeth, all with lips. So no, this sort of crusade against pop culture depictions doesn’t make sense.

Now, let’s look at Cameron, PNSO’s more recent T.rex, and the first model by the company that came out after Cullen et al.’s paper.

We can summarize a review as follows:

It features many improvements, the majority of them in direct response to collectors’ feedback on Wilson (read our review).

First of all, the scales: With the more recent theropod, PNSO has mastered the rendition of the scales to the point where a T. rex model with an updated skin texture (many people do not consider Andrea, which is a shame) was needed.
Furthermore, there’s an exciting change almost no one noticed: the domed feature scales above the arms of every tyrannosaurid up to Zhuchengtyrannus were based on MPD 107 6/A, a skin impression formerly attributed to Tarbosaurus. According to Hendrickx et al. (2022), they were much more likely from a hadrosaurid such as Saurolophus. So, the absence of these scales on Cameron proves how PNSO is attentive to new papers.

“But it has no lips!”

Speaking about attention to detail, the anatomy has been largely improved as can be seen in the front limbs, with even a bump under the second toe indicating the vestigial third finger, more visible jugal horns, and muscles on the temporal fenestra.

Being inspired by “Sue”, whose crushed skull is included as an accessory, this T. rex shows the impressive body we’re now used to, something that the previous figure “Wilson”, based on the more “slender” specimen AMNH 5027, could never achieve even with the addition of gastralia (not that there’s any problem with that).

“Buuut… It has no lips!”

Then, like what happened with Andrea, the taphonomic tooth slippage is corrected (even though it was not so drastic in AMNH 5027), and the pose is less crouched, so no more “Zombie Wilson”, as someone liked to call it.

“Still, no lips!”

I KNOW IT HAS NOT LIPS, I’M NOT BLIND!

Simply enough, PNSO was not convinced by the ideas shared by Witton and other authors on various blogs and kept following Carr’s paper until further research. Any other company that put lips on their theropod figures just bet on the new proposal, which was then “endorsed” by Prehistoric Planet (understandably, if we think of the names involved in the production).

PNSO can have a different opinion, just like some paleontologists, and showed it on many videos, but they must sell their models, and it’s become clear that they can’t fight the “lips trend” (which I do not contest, in case you’re wondering) any longer. Their models are labeled ‘scientific art’, but wasn’t their approach to the absence of lips scientific enough? After all, it was based on Carr’s paper…

Now does it mean the figure, lack of lips aside, doesn’t have anything strange? Well… The number of teeth in its dentary is 16 pairs, far exceeding the number in “Sue”. Although there are clear individual differences in the number of tyrannosaurus teeth ( maybe related to the age of any individual), this number is not consistent with any known T. rex adult specimen. But that’s it, everything else is incredibly well-researched, more than anything on the market at the moment, and all of that got ignored because of the lack of lips (even the issue above).

Sure, we can say that the current consensus requires external oral tissue on theropods, but what if a new “anti-lips” paper came out?

It would be like what happened with Eofauna and Tyrannosaurus imperator: they announced a T. imperator model because of Paul’s paper, but everything changed with the following article.

There’s a high chance that those theropods were already in production when the paper came out, but again, ZHAO Chuang shared his view in the past. Their explanation videos about the two Yangchuanosaurus figures and Saurophaganax are a little controversial, probably because the company needs to make the previous figures still marketable. In the meantime, PNSO released an Alamosaurus with partially exposed teeth and a lipless Spinosaurus.

Another detail many may have missed: the supplementary material of Cullen et al.’s paper suggests a varanid-like gum tissue, partially covering the teeth:

“A further reconstruction of the interior mouth of Tyrannosaurus is presented here to explore a possible implication of theropods having lepidosaur-like lips: specifically, that they may have also borne extensive gingiva that obscured at least some of their teeth.”

Varanus salvadorii is a perfect example of how this tissue would look. Looking at the two Yangchuanosaurus models, it’s clear PNSO made a different choice by sculpting the interior mouth the usual way, with palatal “slots” included. Still, it wouldn’t be wrong in any case, since there’s no certainty.

Paleontological accuracy (or better, the idea of it) is steadily becoming a commercial factor for the dinosaur model business. Still, we should keep in mind that it’s an ever-changing subject. That shouldn’t mean you can’t choose the figure you like the most, but it should depend on all the elements in the equation, not just the trendiest one.