Marasuchus is a precursor to dinosaurs, one of its closest relatives from the genus Dinosauriform Archosaur. It belongs to the same reptilian family tree as dinosaurs, birds, and pterosaurs, the flying reptiles from the Age of Dinosaurs.
This close relative of the mega-dinosaurs that would come next was tiny and started out really low on the food chain, at risk of being eaten by most any other larger predator that lived around it.
“Marasuchus shows us where dinosaurs came from, which were very humble beginnings,” Scott Persons, curator of Natural History at the South Carolina State Museum, told Discover.
There’s a lot we don’t know about Marasuchus. Researchers haven’t found many specimens because it’s small and delicate, with thin limbs that easily break. But what we do know is fascinating.
1. Marasuchus Was Speedy
We know that Marasuchus would have been able to evade the predators constantly chasing it because of its uncanny speed. It had really long legs for its size, making its anatomy ideal for running.
“It was a speedy little reptile,” Persons said.
Additionally, Marasuchus had a tail that helped balance the reptile while it was running and provided greater muscular power to help it run faster. Speed was its superpower, allowing it to survive around much larger animals.
Read More: The First Known Dinos Grew at a Rapid and Continuous Rate
2. Marasuchus Was Small, But Its Ancestors Were Large
Both dinosaurs and pterosaurs, two hugely successful groups, started from Archosaurs, of which Marasuchus was one. These groups would go on to dominate everything on land and in the sky for the next 150 million years.
It lived in modern-day Argentina, dating back to the Late Triassic Period around 230 million years ago, according to the Natural History Museum. Early reptiles, early mammals, and the first dinosaurs, known as Eodromaeus and Eoraptor, all thrived together.
Pterosaurs also appear in the fossil record during the Late Triassic, and they ranged from pigeon-sized to as large as a fighter jet, according to the National Park Service. It’s quite stunning that they started from this tiny creature, about the size of a rabbit.
3. Marasuchus Thrived in Pangea
Marasuchus thrived at a time when all the continents were connected into Pangea, a supercontinent that existed from 300 million to 200 million years ago, according to the American Museum of Natural History. Just before the Triassic, around 252 million years ago, the Earth’s tectonic plates moved together, causing all the continents to collide into one. Large mountain chains were formed at the places where the continents hit one another. Imagine a world where animals such as Marasuchus could walk from one end of the continent to the other.
Just before this, the planet had undergone the most massive extinction ever known, the Permian-Triassic Extinction. The event was caused by massive volcanic eruptions in Siberia, when the continents were initially pushed together to form Pangea by intense plate-tectonic activity, according to Stanford University. The extinction event killed over 70 percent of land animals and 90 percent of marine species.
Read More: World's Smallest Dinosaur May Actually Be an Ancient Lizard
4. Marasuchus Embraced an Evolutionary Opportunity
Not only was there a vacuum to fill after this mass extinction event, but Pangea also made it easier for life to thrive. It’s a creature that shows up at a moment of “evolutionary opportunity” in the late Triassic Period.
Additionally, animals didn’t have to cross any huge barriers because the planets were all connected, so they had their pick of ecosystems. Not to mention that everything had recently been wiped out, so Marasuchus had room to maneuver. The lack of competition allowed this elegant, tiny species to grow and thrive in abundance.
“The extinction event had just occurred, so Marasuchus came with a clean slate,” Persons told Discover.
5. Marasuchus Was Like A Modern-Day Weasel
It’s not that Marasuchus looked like a weasel; it’s just that this is where it likely fit into the food chain. It preyed upon the same types of things that you might expect from something like a weasel. For example, it ate smaller reptiles and insects while larger predators noshed on it.
Lightly built and miniature, a little longer than a foot in length, it maneuvered the undergrowth, hunting its tiny prey and hiding from all those that would want to eat it. Its speed allowed it to both prey upon and avoid becoming prey to a number of species, according to Britannica.
6. Marasuchus Might Have Been Furry And Fuzzy
Researchers don’t know for sure what its outer body would have looked like, though it was initially thought to have scales like a reptile's. In recent years, mounting evidence suggests that the theropod lineage, in particular, might have been covered in primitive feathers, according to the American Museum of Natural History. There’s also evidence that other dinosaur groups had feathers, as did pterosaurs, which has led some researchers to think that feathers were present at the origin of both groups.
“It may be the case that rather than evolving once in dinosaurs and again in pterosaurs, they may have shown up in the same shared common ancestor,” Persons said. This means that rather than Marasuchus appearing as a scaly reptile, it might have been cute and cuddly. Or at least a little fuzzy.
Read More: Dinosaurs May Have Emerged Earlier Than Thought — and Evolved in Rapid Bursts
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from the Natural History Museum: Where did dinosaurs come from?
- This article references information from the National Park Service: Pterosaurs in Big Bend
- This article references information from the American Museum of Natural History: Power Of Plate Tectonics
- This article references information from Stanford University: What caused Earth's biggest mass extinction?
- This article references information from Britannica: Marasuchus
- This article references information from the American Museum of Natural History: A Feathered Tyrant
