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Simosuchus

life science Maturity 11-13 Next article →

Simosuchus is an extinct genus of crocodyliforms that lived during the Late Cretaceous period.

Simosuchus clarki skull
Simosuchus clarki skull

These animals were members of the clade Notosuchia, a group of crocodile relatives. Unlike modern crocodiles that live in water, Simosuchus was a fully terrestrial animal. This means it lived its entire life on land. It is most famous for its unusual skull shape. Its name comes from the Greek words for "pug-nosed crocodile."

Simosuchus scale
Simosuchus scale

This name describes a short, deep snout that looks much like a pug dog. Understanding Simosuchus helps scientists learn how diverse crocodile relatives could be.

Scientists believe Simosuchus was likely a herbivore, which is an animal that eats plants. Most crocodylomorphs are carnivores that hunt meat, but Simosuchus had different tools. Its teeth were shaped like maple leaves. This specialized dentition helped it process vegetation instead of prey.

Simosuchus clarki skull
Simosuchus clarki skull

The snout was also short and deep, which is very different from the long, low skulls of other species. The front part of the skull, called the preorbita, angled downward. This meant the animal likely held its head at a 45-degree angle from the horizon. These physical traits all point toward a life spent eating plants on land.

The skeleton of Simosuchus shows how it moved through its environment. It had robust limbs and strong muscles. The deltopectoral crest on the humerus and a crest on the femur provided places for strong muscles to attach.

Simosuchus skeletal no osteoderms
Simosuchus skeletal no osteoderms

Its hindlimbs were semierect, meaning they were held in a position between sprawled out and directly underneath the body. The animal was also covered in osteoderms, which are bony plates that act like armor. These plates formed a tetraserial paravertebral shield over its back. This shield consisted of four rows of tightly locking plates. This armor was quite stiff and would have limited how much the animal could move side to side.

Researchers first described Simosuchus clarki in the year 2000.

Simosuchus skeletal no osteoderms
Simosuchus skeletal no osteoderms

The initial description was based on a specimen that included a complete skull and lower jaw. Later, five more specimens were found that provided more of the skeleton. Most of these fossils were discovered during the Mahajanga Basin Project. This project was a collaboration between Stony Brook University and the Université d'Antananarivo. The bones were found in clays within the Anembalemba Member of the Maevarano Formation in Madagascar. Interestingly, one isolated tooth of this genus was also found in the Kallamedu Formation of India.

Simosuchus was a relatively small animal, reaching about one meter in length.

Simosuchus scale
Simosuchus scale

Its body structure was quite different from its relatives. It had a very short tail, with no more than twenty caudal vertebrae. Most other crocodyliforms have much longer tails. The spinal column included eight cervical vertebrae in the neck and at least fifteen dorsal vertebrae in the back. The osteoderms on its belly were plate-like with a spongy internal structure called diploë. Meanwhile, the plates on its back and limbs were light and porous. These specific numbers and structures help scientists reconstruct its exact size and shape.

Some scientists have debated how Simosuchus lived on the ground. One idea is that it had a fossorial lifestyle, meaning it was a burrower. This theory was based on its robust limbs and its shovel-like snout. However, other researchers have argued against this. They noted that its head was quite large and wide, which might be difficult for a head-first burrower. They also pointed out that its snout was actually quite flat rather than having a sharp cutting edge. Still, some experts believe it could have used its head to help with scratch-digging using its limbs.

Studying Simosuchus helps us understand the complex history of the supercontinent Gondwana. Most notosuchians lived in this southern landmass, which included Africa and South America. Because the fossil record is incomplete, it is still hard to know exactly how Simosuchus arrived in Madagascar.

Simosuchus
Simosuchus

We know it lived in a world with large predators, such as the snake Madtsoia madagascariensis. By looking at how Simosuchus fits into the family tree of Notosuchia, scientists can trace how different species evolved. It remains a fascinating example of how one group of animals can adapt to many different ways of life.

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🖼️ Images & Media (6)
File:August 1, 2012 - Simosuchus clarki Skull on Display at the Royal Ontario Museum (FMNH PR 2597).jpg
August 1, 2012 - Simosuchus clarki Skull...
File:Simosuchus scale.svg
Simosuchus scale.svg
File:Simosuchus skeletal no osteoderms.png
Simosuchus skeletal no osteoderms.png
File:Simosuchus.jpg
Simosuchus.jpg
File:Simosuchus clarki skull.jpg
Simosuchus clarki skull.jpg
File:Simosuchus BW.jpg
Simosuchus BW.jpg
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