López de Bertodano Formation

The López de Bertodano Formation as it appears in the sixth segment of Oceans

### Temperature

4 - 12 degrees Celsius (39.2 - 43 degrees Fahrenheit) or 7 - 17 degrees Celsius (44.6 - 62.6 degrees Fahrenheit)

### Environment

Open Sea

The **López de Bertodano Formation** is a geological formation found on the James Ross Island of Antarctica, succeeding the Snow Hill Island Formation.

## Description

***“ It's the first time this year's calves will have encountered sea ice. It can be dangerous for an air-breathing reptile. They can only grab a breath of air where there are gaps in the ice. Adults must navigate carefully to find them, and the youngsters must stay close. ”***

― **David Attenborough**, *Oceans*
Around 70 - 66 million years during the Maastrichtian stage of the Late Cretaceous Period, Antarctica's seas were warmer than they were today, interpreted as being either 4 - 12 degrees Celsius (39.2 - 54 degrees Fahrenheit), or 7 -17 degrees Celsius (44.6 - 62.6 degrees Fahrenheit) according to the analysis of ancient bacterial membrane lipids in the region. Regardless, the area would have still been very much cold enough to be covered in sheets of ice, just as depicted in the sixth segment of Oceans.

***“ The Morturneria will feed here all summer until the water ices over again in the polar winter. In warmer waters, they will face other challenges, but the most resourceful animals will always find opportunities in the vast oceans of the Prehistoric Planet. ”***

― **David Attenborough**, *Oceans*
Animals from the López de Bertodano Formation may have plausibly visited other regions of the Southern Hemisphere, as indicated by the teeth of the 12-meter (40-foot) mosasaur *Moanasaurus* being found in both the Tahora Formation and the López de Bertodano Formation. The fragmentary remains of the 15-meter (50-foot) *Mosasaurus hoffmannii*, a species that served as the apex predator of oceans worlwide, have also been uncovered here. The 11-meter (36-foot) elasmosaur *Aristonectes* (the largest plesiosaur ever discovered) is known from both Patagonia and this area, which explains why Prehistoric Planet depicted *Morturneria*, an aristonectine elasmosaur with a sieve of needle-shaped teeth known only from the López de Bertodano Formation, as actually being of South American origin, with the species only visiting the Antarctic waters during springtime, feeding on the tiny creatures living in the seafloor all summer long before returning to South America when winter begins once more.

While known for its marine life, a hadrosaurid (possibly the Snow Hill Island hadrosaur seen in the fifth segment of Ice Worlds or a close relative of it), *Morrosaurus*, a non-avian theropod (possibly *Imperobator* or a close relative), and several species of birds have also been recovered from the area, indicating that at least some part of the López de Bertodano Formation remained above sea level during the Maastrichtian stage of the Late Cretaceous Period.

## Appearance

***“ They are one of the most successful groups of animals to have ever lived, flourishing in the warm, temperate seas, and even the coldest waters at the poles. Like here in the frozen sea around the Antarctic. After a winter of near-total darkness, the low sun is beginning to melt the ice, making it accessible once more for a giant seasonal visitor. ”***

― **David Attenborough**, *Oceans*
The López de Bertodano Formation serves as the setting of the sixth and final segment of Oceans, where a pod of *Morturneria* traveled two thousand miles from South America just in time for spring to warm up the ice-covered Antarctic waters, feeding on the tiny animals that they filter from the seabed with their combs of needle-like teeth. While the show does not depict it within the region, *Kaikaifilu*, a medium-sized mosasaur hailing from the López de Bertodano Formation, was shown prowling the Tahora Formation in the sixth and final segment of Coasts, fended off by several *Tuarangisaurus* when it attempted to attack a pregnant member of their pod.

## Fauna

Antarctic Hadrosaurid*Diplomoceras maximum**Kaikaifilu hervei**Mosasaurus hoffmannii**Morrosaurus antarcticus**Morturneria seymourensis*
## References

1. ↑ 1.0 1.1 I Know Dino: The Big Dinosaur Podcast, Episode 446: Dinosaur-era Oceans and Darren Naish from Prehistoric Planet 2
2. ↑ 2.0 2.1 Late Cretaceous winter sea ice in Antarctica?
3. ↑ 3.0 3.1 A cool temperate climate on the Antarctic Peninsula through the latest Cretaceous to early Paleogene