A study released this week showed how the dinosaur consumed different resources at multiple stages of its development. Modern meat-eating mammals can easily be arranged in a chart showing the average adult size – each of these animals has a unique influence on their ecosystem. Looking at the average size of adult dinosaurs, there appears to be a large gap in the middle of the graph from smallest to largest.
There is a gap in the graph of adult carnivorous dinosaurs for each of the three major periods of the Mesozoic. The Triassic, Jurassic, and Cretaceous periods suffer from a serious shortage of “meat-eating-asurus” (as described by Ariana Richards-Lex in Jurassic Park).
Why in the modern era do we have carnivores in an orderly group, from small to the size of a lion, but in the time of dinosaurs, we didn’t? Researchers from the University of New Mexico and the University of Nebraska have proposed a new theory: Morphospecies.
above: Figure 3: Gap of dinosaurs versus modern carnivorous mammals. (A) Carnivorous mammals of the Kruger National Park are widely organized by mass. (B) Carnivorous dinosaurs to form a dinosaur park if the largest carnivores are evenly scaled to the largest carnivore of mammals in the Kruger. Infants (gray) of the largest species shown below are adults to show relative growth requirements. Photo, description: UNM Biology Department.
You may have heard of the shift from the old way of thinking about dinosaurs and the new, and the transformation over the past few decades that has reduced the number of individual species of dinosaurs from a lot to … much less than previously expected. If you haven’t seen a TED Talk with Jack Horner about “shape-shifting dinosaurs,” I suggest you take the time to do so – it’s one of the most-watched TED talks in TED talk history.
Keep that in mind while reading the rest of the paper that the researchers published this week (shown above). The ancient way of thinking about each individual set of bones as a new dinosaur allowed scientists to see a range of dinosaur sizes that were more “complete”, as we see with modern carnivores. When people like Jack Horner came along, that theory was shattered.
Now, with this latest research, morphology makes sense for the shattered pieces of this puzzle. We don’t see carnivorous dinosaurs filling every gap from small to large because dinosaurs like T-rex have been around, Take advantage of their entire size range Where they have grown from a toddler, out of the egg, to a huge eater of them all.
Tyrannosaurus was so potent carnivores that it had a major impact on the ecosystem in which it lived at every stage of its development. Why have mid-range carnivorous dinosaurs when you can get more T-rex?
For more information, peek at the newspaper The Impact of Juvenile Dinosaurs on the Structure and Diversity of Society Also published in Science. This paper was written by Kathleen Schroeder, S. Kathleen Lyons, and Felisa A. Smith. The research can be found with the code DOI: 10.1126 / science.abd9220 as published in Science Volume 371, Issue 6532, February 26, 2021.