Mad about Science: Perspective on dinosaurs

By Brenden Bobby
Reader Columnist

We have a skewed view of dinosaurs. Much of what we envision when we look back to the ages of dinosaurs has been influenced by a singular media event: Jurassic Park. A fantastic film and one of my favorites that did something incredible for the explosive growth and public awareness of paleontology, but it came with some serious issues that have stuck with us.

Through no fault of Michael Crichton or Steven Spielberg, we all now have a mental image of Tyrannosaurus rex battling with Stegosaurus, and that is just the way of things.

In actuality, humans exist far closer to the time of the T. rex than the T. rex did from the time of Stegosaurus.

The time in which dinosaurs ruled the Earth was vast. I’m talking incomprehensibly vast. Humanity has built civilization in 0.2% of the amount of time that non-avian dinosaurs existed before their extinction. Dinosaurs existed across such an unfathomably huge amount of time that they experienced multiple configurations of continents across the Earth, including the existence and dispersal of one giant supercontinent, Pangaea.

The amount of time required for continents to move is hard to wrap your head around.

Television and movies have given us a very skewed view of dinosaurs even before Jurassic Park. Shows such as Land of the Lost, which ran from 1974-’76 had two very inaccurate depictions of an allosaurus battling a T. rex. Despite the closeness of the two animals’ skeletal structures and potentially even their appearances, they were separated by a gulf of time spanning at least 6 million years. That’s a wider separation than from the existence of Australopithecus, a progenitor genus of Homo sapiens, and the time that you are reading this article.

Another interesting perspective is the existence of flowers and grass. This one was actually briefly illuminated in Jurassic Park, when Laura Dern’s character, Dr. Ellie Sattler, comments on plant life that was being used aesthetically by the park, but was poisonous to the dinosaurs it was growing near. What wasn’t shown was that grasses didn’t exist throughout the vast majority of dinosaur life on Earth.

Grass is one of the most prevalent forms of plant life on the planet. It grows on virtually every landmass, including Antarctica. It’s relatively simple and extremely effective at spreading in huge quantities wherever water and nutrients exist, so it would seem logical that grass would have been one of the first forms of plant life to sprout, right?

Completely wrong.

Grasses are a fairly recent evolution of flora, first appearing around 100 million years ago. This is a very long time, but plant life has existed on Earth in various forms for at least 1.6 billion years. Algae existed on Earth for nearly 1 billion years before plant life as we recognize it began to form.

Plants reproduced clonally for much of their evolutionary history, by either cellular division or sending rhizomes into the surrounding environment to create new clones. Cloning is a risky form of reproduction, as it can be efficient until it comes under threat by external sources such as rapidly evolving diseases or a changing climate. Clones are unable to share genetic material and build defenses against these threats over generations and are far more prone to extinction because of it.

Eventually, plants began using waterborne sperm or airborne pollen and seeds, which worked well for at least 500 million years. Flowers didn’t appear until roughly 150 million years ago, which is really interesting when you consider that pollinating insects existed for 150 million years prior to that. So how did pollinators exist when flowers didn’t?

Trees still produced pollen without producing flowers, by dispersing gymnosperm that would be carried by the wind. That proved to be less effective than letting insects do it however, so over the course of 150 million years, plants evolved to produce flowers that were attractive to these insects. It proved to be such a successful method of reproduction that flowers evolved into myriad shapes and colors adapted to each environment in which the plant existed, causing an evolutionary boom of plant life during the Cretaceous and beyond.

How this relates to dinosaurs is that the vast majority of dinosaurs that existed never saw a flower or grass. The first dinosaurs appeared roughly 250 million years ago, the first flowering plants around 150 million years ago, the first grasses around 100 million years ago and the asteroid that wiped out all non-avian dinosaurs struck around 65 million years ago.

The stegosaurus, one of the largest herbivores to ever walk the Earth, never ate grass. In fact, we exist closer to the time of the T. rex than the stegosaurus did to grass, having been separated by a span of 100 million years.

All of this talk of time doesn’t even touch on the matter of space. Jurassic Park skewed our view of dinosaur coexistence, and intentionally so. Velociraptor, no matter how inaccurately it was anatomically depicted on screen, did in fact live at the same time as the T. rex. The two never crossed paths over the course of 20 million years, however, being separated by the Pacific Ocean.

Stay curious, 7B.