López de Bertodano Formation

López de Bertodano Formation
The López de Bertodano Formation as it appears in the sixth segment of Oceans
Location
Supercontinent	Gondwanaland
Continent	Antarctica
Unit of	Marambio and Seymour Island Groups
Region	James Ross Island, James Ross Archipelago
Overlies	Snow Hill Island Formation
Temporal Range	70 - 66 million years ago, Maastrichtian Stage, Late Cretaceous Period
Episodes	Oceans (Segment 6)
Filmed In	Kronören and Ormberget-Hertsölandet nature reserves, Sweden Breakwater Fort in Dorset, England
Characteristics
Climate	Polar, Subpolar, Temperate
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.

Paleoenvironment

“ 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.

A hadrosaur, Morrosaurus, a non-avian theropod (possibly Imperobator or a close relative), and at least six species of birds have been recovered from this region, 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. However, this area is more known for the fauna that make up its marine ecosystem.

“ 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

Sea life 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 (justifying why Kaikaifilu, a mosasaur native to the López de Bertodano Formation, is portrayed visiting the warmer waters of the Tahora Formation in New Zealand in the sixth segment of Coasts). The fragmentary remains of the 15-meter (50-foot) Mosasaurus hoffmannii, a species that served as the apex predator of oceans worldwide, 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. A third elasmosaur, Marambionectes, is also found in the López de Bertodano Formation. It is likely that all three elasmosaurs of the region occupied different ecological niches, avoiding competition with each other in various ways like preferring different types of food or living in distinct environments or depths.

“ Polar mud, full of small creatures. There can be hundreds of tiny animals in every square foot of seafloor. Separating what's edible from the sticky mud is a challenge. But they have a neat solution. ”

― David Attenborough, Oceans

The López de Bertodano Formation is also home to several sharks, several bony fish like Enchodus (which resembles Xiphactinus, a larger, unrelated predatory fish of another order), and invertebrates, among them, Diplomoceras and seven other ammonites, the nautilus Eutrephoceras, the serpulid polychaete worm Rotularia (previously mistaken for a sea snail due to its gastropod-like shape), two species of the sea urchin Cyathocidaris, gastropods, and bivalves.

Ultimately, most of the animals in the López de Bertodano Formation were driven to extinction by the Cretaceous-Paleogene Extinction Event 66.043 million years ago, a catastrophe that wiped out three-quarters of all life on Earth, including all non-avian dinosaurs, pterosaurs, plesiosaurs, and mosasaurs. However, a few animals in the area like the ammonite Pachydiscus survived into the Danian stage of the Early Paleocene Period, approximately 61.6 million years ago.

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.

Paleofauna

Antarctic Hadrosaur

Diplomoceras maximum

Kaikaifilu hervei

Morrosaurus antarcticus

Morturneria seymourensis

Mosasaurus hoffmannii