Mar 31 2023
T-rex Had Lips
One of the challenges of paleontology is that we are trying to infer and entire animal just from the hard parts that fossilize, mostly bones and teeth (and sometimes just teeth). But if we look at animals today there are a lot of details we could not guess from their bones alone – the mane of a lion, the humps on camels, or the amazing display of peacocks. Soft tissue is rarely preserved, so in many cases we simply have to guess. If we look at the classic depictions of dinosaurs, we see creatures that are all drab in color and don’t have any significant soft-tissue adaptations. We are getting better and inferring color from fossilized melanosomes. We are also discovering that many dinosaurs had feathers, and those feathers were probably colorful. In fact, that clade (just think of birds) have lots of integumentary adaptations, not just feathers. Turkeys are a good example. It’s just as likely, therefore, that dinosaurs had lots of interesting integumentary structures hanging off of them.
A recent study highlights one method that scientists can use to gain more information about the soft tissue of dinosaurs. They looked at the teeth of T. rex, crocodilians, and lizards. Their question was – did T. rex have a toothy smile like an alligator, or fleshy lips covering their teeth like lizards? They have been imagined both ways, but Jurassic Park probably solidified the image for many people of a toothy T. rex. There is definitely something more menacing about a grill of visible deadly carnivore teeth.
What they did was look at the teeth, which is the hardest part of vertebrates and fossilize very well. Specifically they looked at the wear on the teeth. If fleshy lips covered the teeth, they would have been protected from wear along the covered surface. When looking at the teeth of crocodilians vs lizards we see this difference. So all we have to do is examine T-rex teeth to see if they have wear patterns that look like a crocodiles or a lizards. They also did an analysis of skull size and tooth length to see if there was also a relationship there. They found:
Contrary to depictions that have dominated for more than a century, they found that theropods, including T. rex, had lips that covered their teeth, leaving them looking more like modern Komodo dragons than crocodiles.

The world produces about 380 million tons of plastic every year, and half of that is single use plastic. This figure is projected to increase by 70% by 2050. A 2017 study found that of all the plastic produced, “9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment.” Current practices are unsustainable, as a lot of this plastic ends up in the oceans and elsewhere in the environment. Researchers are increasing looking to bacteria as one potential solution to this problem.
Happy New Year to all my readers.
It’s always fun and interesting to look back at the science news of the previous year, mainly because of how much of it I have forgotten. What makes a science news item noteworthy? Ultimately it’s fairly subjective, and we don’t yet have enough time to really see what the long term impact of any particular discovery or incremental advance was. So I am not going to give any ranked list, just reminisce about some of the cool science and technology new from the past year, in no particular order. I encourage you to extend the discussion to the comments – let me know what you though had or will have the most impact from the past year.
As we discuss the optimal path forward for the next 30 years to get to net-zero carbon emissions for the energy sector, one big variable is the real-world potential of geothermal energy.
Archaeologists have uncovered a large cache of over 50 small bronze statues in the ruins of an ancient temple in Tuscany. The find dates from the second century BCE to the first century ACE. It is being reported as the greatest bronze statue find in 50 years, one of the greatest finds ever, and a significant window into that period of history.




