Shamosuchus

## ShamosuchusSand Desert Crocodile

### Temporal Range

83.6 - 72.1 million years ago, Campanian Stage, Late Cretaceous Period (possibly around up to 70 million years ago, Maastrichtian Stage)

## Characteristics

### Diet

Carnivore

***“ Shamosuchus. Fifteen feet-long predators. This island might offer safety, but the surrounding waters certainly do not. ”***

― **David Attenborough**, *Swamps*
***Shamosuchus*** (Sand Desert Crocodile, named after the Chinese term for the Gobi Desert, "sha mo", which means "sand desert") is an extinct genus of paralligatorid neosuchian crocodylomorph that lived in the Djadochta Formation in Mongolia, 83.6 - 72.1 million years ago, during the Campanian stage of the Late Cretaceous Period. Prehistoric Planet depicts *Shamosuchus* as living in the obscure, lacustrine Songliao Basin of China.

The animal depicted on Prehistoric Planet is actually meant to be *Paralligator* (Near Alligator), which is known from the Nemegt Formation in what is now the Gobi Desert of Mongolia, 70 million years ago, during the Maastrichtian stage of the Late Cretaceous Period. Both *Shamosuchus* and *Paralligator* have been considered one and the same by some studies in the past, though it is now believed that, while closely related, they were distinct from one another given their differences, like the significantly shorter snout of *Shamosuchus*. While both *Shamosuchus* and *Paralligator* lived slightly before Prehistoric Planet's mostly Maastrichtian setting, it is still reasonable enough to believe that some of them did persist a bit longer past the time range indicated by their fossils.

## Description

*Shamosuchus* is a paralligatorid neosuchian crocodylomorph that reached lengths of 4 - 4.6 meters (13 - 15 feet). Its actual mass is not known, but based off of modern crocodiles of equivalent size, it might have weighed around 300 - 600 kilograms (661 - 1300 pounds). However, it should be noted that paralligatorids may not have had the exact same proportions or mass as modern crocodylomorphs, and thus may have been lighter or heavier than them. In truth, while paralligatorids may superficially resemble crocodiles, they are different enough that they cannot simply be portrayed, live-acted, or substituted by modern-day crocodilians.

The eyes and nasal openings of *Shamosuchus*, unlike those of modern crocodiles, were not raised above its short skull, meaning that it would need to raise its head completely out of the water to breathe. This indicates that, unlike modern crocodiles, *Shamosuchus* is not an ambush predator, with this, coupled with teeth suited for crushing, suggesting that it went for shelled aquatic invertebrates like bivalves or gastropods.

## Habitat

***“ The vast swamplands of northeast Asia. Within this low-lying, flooded territory, there are countless islands. Each of them is surrounded by slow-moving waters. And that makes them potential sanctuaries for new life. ”***

― **David Attenborough**, *Swamps*
*Shamosuchus* lived 83.6 - 72.1 million years ago in the Djadochta Formation in the Gobi Desert of Mongolia, which underlies the Barun Goyot Formation, which is in turn found under the Nemegt Formation. While the area was, for the most part, a semi-arid desert much how it is in its current state, occasionally, bodies of water form, providing *Shamosuchus* with shelter, albeit temporarily.

However, Prehistoric Planet does not depict *Shamosuchus* in this arid desert environment. Instead, it depicts *Shamosuchus* as living in the river deltas and swamps of the lacustrine (lake-filled) Songliao Basin in China. Most of what is known about the region is based on one particular area within it, the Nenjiang Formation, which does hold crocodylomorphs, molluscs, fish, turtles, mammals, as well as dromaeosaurs, troodontids, and a possible tyrannosaur (all of the aforementioned dinosaurs are only known from teeth, however). The region dates back to the Santonian and Campanian stages of the Late Cretaceous Period, being approximately 83 - 85 million years old, but a comment made by Dr. Darren Naish, Prehistoric Planet's lead consultant, implies that the segment *Shamosuchus* appeared in is still meant to take place during the Maastrichtian stage of the Late Cretaceous, around 72 - 66 million years ago, indicating that this particular section of the Songliao Basin is much younger than its other parts.

## Behavior

The *Shamosuchuses* are shown to be opportunistic and persistent predators, alerted by newly-hatched juvenile azhdarchids trying to fly over their waters and taking advantage of these easy meals, with some leaping out of the water to grab low-flying pterosaurs, while others would go so far as to get up on land and chase some of the newborn pterosaurs. Such behavior can be seen in crocodiles today, which would throw their heads sideways out of the water in an attempt to grab or at least collide with bats flying overhead.

## Appearance

* Greenfield Lake Park, Wilmington, North Carolina, USA
* Okefenokee National Wildlife Refuge, Georgia, USA
* Black River, North Carolina, USA

**Swamps**, Segment I
**Setting**
Songliao Basin, Songnen Block, northeast China

**Filming Location**

* Greenfield Lake Park, Wilmington, North Carolina, USA
* Okefenokee National Wildlife Refuge, Georgia, USA
* Black River, North Carolina, USA

In the first segment of Swamps, on the islands of vast swamplands in northeast Asia, are newly-hatched juvenile azhdarchids. One female, only a few hours old, takes her first steps and practices flight within the safety of the hatching grounds. To feed, however, the young azhdarchids need to fly out of their sanctuary and make their way to the forests past the swamps, with the light breeze of the day providing some help with extra lift. One youngster flies off, but, with insufficient strength, it loses lift and lands in the water. As it resorts to just swimming all the way to the forest on the other side of the swamp, it is grabbed by a *Shamosuchus*. Sensing an incoming feast, several more *Shamosuchus* emerge from the mangroves, closing in on the island of the youngsters.

***“ If their takeoff isn't perfect, it's difficult to gain height. And this is not high enough. Some of the stronger fliers have almost reached the safety of the forest. Others have still to make their attempt. ”***

― **David Attenborough**, *Swamps*
More hatchlings attempt to fly for the forest, but some fly too low and get grabbed in midair, while others splash into the swamp and become easy pickings either way. Some of the stronger fliers were close to reaching the forest, while others are still hesitant to take off. Staying on the island is not an option, however, as one *Shamosuchus* clambers up onto land and begins chasing the female juvenile from earlier. Left with no choice, she runs for the edge of the island and take flight. Appearing to be successful at first, the juvenile slowly loses height, but still seems to be close to her destination. Suddenly, a *Shamosuchus* springs out of the water and almost grabs her, the impact causing the juvenile to plummet into the water, forcing her to swim the rest of the way to the forest, the *Shamosuchus* right on her tail. Upon reaching land, the crocodilian continues to go after her, but she manages to run off and finally evade her pursuer by taking flight once again, going further inland before landing on a rock, safe at last.

***“ A near-miraculous escape. And now, the chance to collect her rewards. In these rich swamp forests, there's all the food she needs. ”***

― **David Attenborough**, *Swamps*
Seeing a lizard scampering across the roots of the trees, the young azhdarchid pursues it and snaps it up. In this forest, she and the rest of the survivors will grow, with plenty of food around them. The feeding opportunity over, one *Shamosuchus*, flies buzzing and walking atop its head, submerges back to the depths of the swamp.

## References

### General

1. ↑ 1.0 1.1 Based on modern-day crocodiles of equivalent size according to "Scientific results of an inquiry into the ecology and economic status of the Nile Crocodile (*Crocodilus niloticus*) in Uganda and Northern Rhodesia" and "How Did the Massive 'Salty' Crocodile Captured in Australia Get So Freaking Big?"
2. ↑ Efimov, M. B. (1983). "Review of fossil crocodiles of Mongolia". *Transactions of the Joint Soviet–Mongolia Paleontological Expedition*. **24**: 76–95.
3. ↑ Rozhdestvenskiy, A. K. (1974). "History of the dinosaur fauna of Asia and other continents and questions concerning paleogeography". *Transactions of the Joint Soviet–Mongolia Paleontological Expedition*. **1**: 107–131
4. ↑ Storrs, G. W.; Efimov, M. B. (2000). "Mesozoic crocodyliforms of north-central Eurasia". In Michael J. Benton; Mikhail A. Shishkin; David M. Unwin; Evgenii N. Kurochkin (eds.). *The Age of Dinosaurs in Russia and Mongolia*. Cambridge University Press. pp. 402–419
5. ↑ Turner, A. H. (2015). "A Review of *Shamosuchus* and *Paralligator* (Crocodyliformes, Neosuchia) from the Cretaceous of Asia".
6. ↑ The Geology of Ukhaa Tolgod (Djadokhta Formation, Upper Cretaceous, Nemegt Basin, Mongolia)
7. ↑ First discovery of theropod teeth from the Nenjiang Formation (early Campanian) in the Songliao Basin, northeast China

### Dr. Darren Naish

1. ↑ 1.0 1.1 The animal depicted on Prehistoric Planet should have been *Paralligator*, since *Shamosuchus* has a much shorter snout than it. Although *Shamosuchus* and *Paralligator* precede Prehistoric Planet's Maastrichtian setting, it is reasonable enough to speculate that some of them may have survived for longer than the fossil records show.
2. ↑ It is important to take note that no Mesozoic croc-like animal is actually a crocodile or even a crocodylian, though these animals are members of the more inclusive clade of crocodyliformes. These animals are very different from modern crocodiles and alligators, so these animals can't simply be portrayed and live-acted by modern-day crocodilians, though paralligatorids do resemble crocodiles to a degree.
3. ↑ *Shamosuchus* attempting to grab pterosaurs flying overhead is based on the behavior of modern-day crocodiles, with Australian freshwater crocodiles documented trying to grab bats.

### Prehistoric Planet

1. ↑ 1.0 1.1 As stated in Swamps.
2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 I Know Dino: The Big Dinosaur Podcast, Episode 445: Dinosaurs in Swamps: Featuring Prehistoric Planet 2