Morturneria

## Morturnerianamed in honor of Dr. Mort Turner

Has outward-pointing, interlocking needle-like teeth that formed a sieve for filter-feeding

***“ Morturneria, a strange type of elasmosaur. They are warm-blooded, with a thick layer of blubber which conserves the heat in their body. They're one of the world's most secretive and elusive animals. ”***

― **David Attenborough**, *Oceans*
***Morturneria*** (named after Dr. Mort Turner, one of the paleontologists interested in the studies taking place on Seymour Island) is a genus of elasmosaurid plesiosaur that lived in the López de Bertodano Formation, Seymour Island, Antarctica, 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Description

### Size and Physique

*Morturneria* is a small-bodied elasmosaurid known from the remains of what is believed to be a juvenile specimen 3 - 4 meters (10 - 13 feet) in length. Prehistoric Planet depicts the adults as being at least twice the size of their calves, giving them a speculated possible size of 8 meters (26 feet), much like *Tuarangisaurus*, their relative from New Zealand, thus, it was also likely as heavy, being up to one metric ton (1.1 short tons). It was, in essence, medium-sized by elasmosaur standards, with studies in 2003 interpreting it as a mere juvenile stage of the elasmosaur *Aristonectes*, one of the largest-known plesiosaurs, possessing a length of 11 - 12 meters (36 - 40 feet), a mass of 10.7 - 13.5 metric tons (11.8 - 15 short tons), and a finspan of 7 meters (23 feet), though later studies in 2017 and 2019 would determine that, while the holotype of *Morturneria* likely belonged to a juvenile specimen, it was indeed its own distinct taxon.

### Dentition

*Morturneria* and several of its relatives are known for possessing combs of needle-like teeth that pointed outward instead of downwards, interlocking to form a sieve, a clear indication that the animal is a filter feeder.

### Polar Life Adaptations

Although the Earth was warmer during the Mesozoic Era, some areas of the planet were still subject to harsh cold temperatures. Given their cosmopolitan distribution, plesiosaurs, most especially polar species like *Aristonectes* and *Morturneria*, would have needed special adaptations to help them survive in such frigid conditions. Studies indicate that, much like many dinosaurs and pterosaurs, plesiosaurs and other marine reptiles were, to a degree, endothermic (warm-blooded), possessing a metabolism between those of most reptiles (which were ectothermic, cold-blooded) and avian dinosaurs (more commonly known as birds, which generally have better metabolisms than their non-avian counterparts). In fact, there is even evidence that at least some plesiosaurs possessed blubber (or, at the very least, subdermal fat much like blubber). With these adaptations, *Morturneria* can survive even in the freezing waters of Antarctica.

## Habitat

*Main: López de Bertodano Formation*

Main: López de Bertodano Formation

***“ 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*
*Morturneria* lived 66 million years ago in the López de Bertodano Formation of Seymour Island, which showed that the waters surrounding Antarctica were warmer than they are in the modern day, though, at 4 - 12 degrees Celsius (39.2 - 54 degrees Fahrenheit), the area was still very much cold, hence, the seas of Antarctica would have still been plausibly covered in sheets of ice, just as depicted in the sixth segment of Oceans. The *Morturneria* pod on Prehistoric Planet is stated to have come from South America, a speculation supported by the fact that other Antarctic plesiosaurs have also been found in Patagonia.

In the cold waters of the López de Bertodano Formation, *Morturneria* would have faced threats in the form of several mosasaurs known to have lived in the region, from the 10-meter (33-foot) *Kaikaifilu* (a native tylosaurine depicted by the show as also residing in New Zealand in the sixth segment of Coasts) and the 12-meter (40-foot) *Moanasaurus* (known from fossils in New Zealand, speculated to also live in Antarctica based on isolated teeth), to the 15-meter (50-foot) *Mosasaurus hoffmannii* (whose presence in the area is also implied by fragmentary remains), the largest predator that lived on Earth during the Cretaceous Period. The environment itself could also pose dangers just as it does for several diving animals today, with many parts of the seas covered by ice that may prevent air-breathing animals from reaching the surface to breathe in time.

## Behavior

### Feeding Preferences

***“ These cold waters are an excellent habitat for this giant's favorite food. 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. Scooping up a mouthful, they partially close their jaws, creating a giant sieve to filter out the food. These are the only animals to have evolved teeth to feed in this way. ”***

― **David Attenborough**, *Oceans*
Given its unique dentition, it is believed that *Morturneria* is a filter feeder, sucking up sediments and water which it then forcibly ejects, its combs of needle-like teeth straining organisms for consumption.

*Morturneria* is not the first animal to have evolved such specialized features. Many prehistoric creatures that preceded it, from the Ordovician radiodont arthropod *Aegirocassis* and the Late Triassic placodont *Henodus* to the ctenochasmid pterosaurs (most notable of these being the Early Cretaceous Brazilian pterosaur *Pterodaustro*), evolved their own sets of fine meshes to exploit and dominate the filter-feeding niche. Even so, ancient reptiles with filter-feeding adaptations were conspicuously rare finds, and the notion that a marine reptile would evolve features and feeding habits similar to those of baleen whales was long considered anatomically impossible, an idea that *Morturneria* and its relatives finally overturned, further proving that prehistoric creatures were more diverse than previously thought.

### Migratory Habits

***“ This pod has migrated nearly two thousand miles from South America to arrive here in time for spring. ”***

― **David Attenborough**, *Oceans*
Although it is only known from the López de Bertodano Formation, *Morturneria* is depicted as merely a seasonal visitor and not a year-round inhabitant of Antarctica. The idea that it may have lived in South America is based on fossil evidence of other Antarctic plesiosaurs like *Aristonectes* being found in various parts of Patagonia. While *Morturneria* likely had the physiological adaptations needed to resist the cold temperatures from endothermic (warm-blooded) metabolism to thick layers of blubber, visiting the area only during springtime, right when winter ends, is a behavioral adaptation that can help ensure the animal's survival. By avoiding the coldest time of the year, *Morturneria* doesn't need to expend as much energy or resources to maintain and stay within the acceptable limits of its physiological adaptations.

### Parental Habits

***“ 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*
Based on fossil evidence, plesiosaurs are known to give live birth to a single large calf around a third of the mother's size. It is therefore believed that plesiosaurs relied on the K-selection strategy much like whales, elephants, and humans, usually giving birth to as little as one offspring at a time, a large, slow-growing baby that they provide with great parental care, increasing the chances of the juvenile reaching adulthood. This is in sharp contrast to most reptiles (including most dinosaurs and pterosaurs, as depicted on Prehistoric Planet), which usually rely on the r-selection strategy, spawning many quick-growing offspring which they provide with little to no parental care (with the idea being that, even though many will inevitably die due to various factors from predation to environmental conditions, many more will survive to adulthood and continue the cycle).

The great parental care provided by plesiosaurs is mostly seen in the third and sixth segments of Coasts, which feature *Tuarangisaurus* giving birth to large calves and continuing to rear them even when they're two years old. *Morturneria* also shows this off to an extent, with the parents providing guidance for the calves (already half the size of their parents), some of which have not yet experienced navigating through the ice-covered seas of Antarctica.

## Appearance

* Kronören and Ormberget-Hertsölandet nature reserves, Sweden
* Breakwater Fort in Dorset, England

**Oceans**, Segment VI
**Setting**
López de Bertodano Formation, James Ross Island, James Ross Archipelago, Antarctica

**Filming Location**

* Kronören and Ormberget-Hertsölandet nature reserves, Sweden
* Breakwater Fort in Dorset, England

The sixth and final segment of Oceans takes place in the frozen seas surrounding Antarctica. After a long, cold winter of almost-total darkness, the low sun shines down for the first time in months, melting and opening up some gaps in the ice. Emerging from one of these gaps is a *Morturneria* followed by its calf, which snuggles up to its parent. These *Morturneria* are part of a pod that traveled 2000 miles from South America to feast in the Antarctic during spring. Within another ice gap, a small group of four *Morturneria*, are shown resting up for the moment. One calf dives down under the ice to emerge out of another ice gap just a short distance nearby, where four adult *Morturneria* are waiting.

Deciding it is now time to feed, the pod of elasmosaurs descend to the depths, scraping their half-closed jaws against the the sea floor (with some sweeping their mouths horizontally across the seabed, and others rushing forward to shovel in a mouthful of it), scooping up the mud and filtering out the hundreds of tiny animals with their sieve-like combs of needle-like teeth. A *Morturneria* calf returns to the surface to briefly take a breath of air, then dives back down to rub against its mother before surfacing with her to breach the surface.

***“ 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*
The segment ends with the calf swimming around in the ice gap under the watch of its mother as the view zooms out to show the extent of the frozen seas of Antarctica under the light of the low sun.

## References

1. ↑ As stated in Oceans
2. ↑ 2.0 2.1 2.2 Description and histology of a small-bodied elasmosaur and description of *Mortuneria seyemourensis* postcranium
3. ↑ The elasmosaurid plesiosaur *Aristonectes* Cabrera from the latest Cretaceous of South America and Antarctica
4. ↑ A giant elasmosaurid (Sauropterygia; Plesiosauria) from Antarctica: New information on elasmosaurid body size diversity and aristonectine evolutionary scenarios
5. ↑ 5.0 5.1 Cranial anatomy of *Morturneria seymourensis* from Antarctica, and the evolution of filter feeding in plesiosaurs of the Austral Late Cretaceous
6. ↑ Regulation of Body Temperature by Some Mesozoic Marine Reptiles
7. ↑ A new polycotylid plesiosaur with extensive soft tissue preservation from the early Late Cretaceous of northeast Mexico
8. ↑ Late Cretaceous winter sea ice in Antarctica?
9. ↑ Pregnant Fossil Suggests Ancient 'Sea Monsters' Birthed Live Young
10. ↑ 10.0 10.1 10.2 I Know Dino: The Big Dinosaur Podcast, Episode 446: Dinosaur-era Oceans and Darren Naish from Prehistoric Planet 2