Morrosaurus

## Presence

### Location

Snow Hill Island and López de Bertodano Formations, James Ross Island, Antarctica

### Temporal Range

71 - 66 million years ago, Maastrichtian Stage, Late Cretaceous Period

## Characteristics

### Diet

Herbivore

 **Main** Gallery

MainGallery

***“ A Morrosaurus. A plant eater for whom winter is inevitably a very hard time. Imperobators specialize in hunting such prey. ”***

― **David Attenborough**, *Islands*
***Morrosaurus*** (El Morro Lizard, a reference to the site it was found in, El Morro on James Ross Island) is an extinct genus of herbivorous ornithopod dinosaur that lived in the Snow Hill Island and López de Bertodano Formations, James Ross Island, Antarctica, 71 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Description

Only known from a right hind leg, *Morrosaurus*, with a length of 4.6 - 5 meters (15 - 16 feet), is larger and more robust than its relatives, like *Trinisaura*, which, at 1.5 meters (5 feet) is around three times smaller. Nevertheless, it is still very much small, fast, and lightweight by ornithopod standards. It is part of a clade known as "Elasmaria", which consists of small, bipedal ornithopods which used to be grouped together in a now-invalid family known as "Hypsilophodontidae".

Prehistoric Planet depicts *Morrosaurus* with a feathered coat in shades of brown and gray, thus avoiding the tendency to portray dinosaurs in cold regions with coats as white as snow.

## Habitat

*Main: Snow Hill Island Formation, López de Bertodano Formation*

Main: Snow Hill Island Formation, López de Bertodano Formation

***“ In the far south of the planet, on the islands of the Antarctic peninsula, winter brings months of freezing temperatures. Here, too, being part of a family brings benefits. ”***

― **David Attenborough**, *Islands*
*Morrosaurus* lived 71 - 70 million years ago in the Snow Hill Island Formation, James Ross Island, Antarctica. During that time, Earth's climate was much warmer and more humid than today, thus, Antarctica would have had a climate similar to those of modern-day volcanic arcs supporting large, dense conifer forests, cycads, and ginkgos. Even back then, however, much like Antarctica today, the inhabitants of the island had to endure a long period of cold, dark months during the winter, and hence had to adapt to the freezing temperatures as snow and ice cover up the temperate forests of the region.

Traces of *Morrosaurus* are also known from the López de Bertodano Formation, the successor of the Snow Hill Island Formation, indicating that it lived up to 66 million years ago, making it a likely witness and victim of the Cretaceous-Paleogene Extinction Event which wiped out three-quarters of life on Earth, including all non-avian dinosaurs.

## Behavior

***“ The Morrosaurus is faster than its pursuers. But it's outnumbered by the pack. ”***

― **David Attenborough**, *Islands*
Due to the harsh conditions, *Morrosaurus* struggles during wintertime, forced to resort to digging for what ever sustenance is left buried in the snow-covered ground of the freezing forest. While the animal's social habits are unknown, Prehistoric Planet depicts *Morrosaurus* as a solitary animal. Without the safety provided by the numbers of a herd, the ornithopod is more vulnerable to getting targeted and cornered by predators, especially pack hunters like *Imperobator*, so *Morrosaurus* has to stay alert at all times.

During its segment, the different maneuvering methods of both predator and prey are shown. The *Imperobators* use their forearms and their tails (which constantly swing as they run) to balance themselves, control their descent, and help steer their bodies while running, serving as brakes, much like a ship's rudder or a cheetah's long tail. The *Morrosaurus*, on the other hand, uses the mass of its tail to shift its center of gravity and make sharp turns, a skill that ultimately allowed it to get away from its pursuers.

## Appearance

* Abraham Lake, Alberta, Canada
* Callaghan Valley, British Columbia, Canada
* Alvie and Dalraddy Estates, Scotland

**Islands**, Segment V
**Setting**
Snow Hill Island Formation, James Ross Island, James Ross Archipelago, Antarctica

**Filming Location**

* Abraham Lake, Alberta, Canada
* Callaghan Valley, British Columbia, Canada
* Alvie and Dalraddy Estates, Scotland

In the fifth, penultimate segment of Islands, deep within a freezing hillside forest, a family of five *Imperobators* are viewed through a thermal camera. To get food for the pack and maintain the heat they have, three of them set off to find food. The three hunters travel downhill, the snow muffling the sounds of their feet, enabling to move undetected as they search for prey. In the forest, a lone *Morrosaurus* is seen struggling to forage for food through the snow, with the *Imperobators* slowly approaching it from the cover of the trees. Sensing their presence, the *Morrosaurus* immediately runs down the slope of the snowy hill, its hunters rushing out to pursue it.

***“ The chase has reached the very edge of the forest. Beyond lies a frozen lake, half a mile wide. The clear, open space could give the faster Morrosaurus an advantage. But the frozen surface is treacherous. With the Imperobator closing in, it isn't much of a choice. ”***

― **David Attenborough**, *Islands*
Upon exiting the forest, the *Morrosaurus* is greeted by a frozen lake. While it can better use its superior speed in this open area to lose its pursuers, the elasmarian hesitates due to the possible dangers of frozen, slippery surface, which could potentially be fragile in some places. Left with no choice due to the hunters closing in on it, the ornithopod rushes across the frozen lake, the three theropods just right behind. Swinging its tail to shift its center of gravity, the *Morrosaurus* makes a tight turn, avoiding the jaws of one of the *Imperobators* in a nick of time, causing the hunter to slip as its two other packmates behind it continue the chase.

***“ A misplaced step, a chance for the Morrosaurus to sprint beyond the predators' reach. But this is an island, so hunters and hunted will almost certainly meet again. ”***

― **David Attenborough**, *Islands*
As the *Morrosaurus* ultimately gets away, the two other *Imperobators* halt their pursuit. In frustration, one snaps in the direction of the *Morrosaurus*, likely insisting that the hunt be continued, while the other, just as exasperated, snaps back, forcing the other to flinch away. As vexing as it is, they must accept that the hunt is over and their prey has evaded them, though only for that specific encounter. With that, the *Imperobators* cut their losses and walk away.

## Gallery

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## References

### General

1. ↑ 1.0 1.1 Biological implications of the bone microstructure of the Antarctic ornithopods *Trinisaura* and *Morrosaurus* (Dinosauria, Ornithischia)

### Dr. Darren Naish

1. ↑ Prehistoric Planet avoided giving the dinosaurs of Antarctica white coats.
2. ↑ The winters of prehistoric Antarctica would have still covered the land in snow and ice, hence, animals back then would have needed to adapt to these changes.
3. ↑ Different maneuvering techniques were planned for both *Imperobator* and *Morrosaurus*.

### Prehistoric Planet

1. ↑ 1.0 1.1 1.2 1.3 I Know Dino: The Big Dinosaur Podcast, Episode 443: Dinosaurs on Islands. Featuring Prehistoric Planet 2