“ 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. ”
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.
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.[1] 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) like Tuarangisaurus, a relative from New Zealand, thus, it was also likely as heavy, weighing around 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,[2] 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),[3] 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.[4][1]
Jaws and 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. To complement this, the show portrays Morturneria with speculative pleats, long, parallel grooves that travel down their throats. In the modern day, rorquals possess such furrows (making them unique amongst other baleen whales), which help them to expand their throats when they lunge forward so that they can take in as much krill as possible lunge forward. One exception to this is the gray whale, which does not rely on lunge-feeding, but instead turns on its side to scoop up sediments from the sea floor to filter out benthic crustaceans, similar to how Morturneria is depicted feeding on Prehistoric Planet.
Senses[]
Elasmosaurids possess large eyes that are directed relatively upward, as well as a strong sense of smell. It is mostly believed that hearing is not important for elasmosaurids, hence, they appeared to have completely lost their stapes (also known as stirrups, inner ear bones that help conduct sound towards an organism's cochlea), instead relying on organs sensitive to electrical signals (like the Ampullae of Lorenzini present in certain types of fish) or changes in pressure (like the integumentary sensory organs of crocodiles), as indicated by possible evidence of electroreceptors and mechanoreceptors in other types of plesiosaurs like polycotylids and pliosaurs.[5][6] Surprisingly, however, a study in 2017 confirmed that at least one elasmosaur from the Late Cretaceous Period, Tuarangisaurus, had stapes, indicating that elasmosaurs retained this inner ear bone after all,[7] though it remains unclear how well elasmosaur's auditory sense is, which can help determine the degree of importance of hearing in the animal's life.
Given how it searches the bottom of the ocean for sustenance, combing through the substrate of the sea floor, Morturneria may have likely relied on the detection of chemicals, electrical signals, and the smallest movements made by its prey, hence, though it is not confirmed what senses it did evolve and enhance, it is reasonable to believe that electroreceptors, mechanoreceptors (pressure sensors), and a strong sense of smell would have been of utmost importance for its preferred lifestyle.
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, as is the case for 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).[8] In fact, there is even evidence that at least some plesiosaurs possessed blubber (or, at the very least, subdermal fat analogous to blubber).[9] With these adaptations, Morturneria can survive even in the freezing waters of Antarctica.
Prehistoric Planet's Portrayal[]
Prehistoric Planet portrays Morturneria with bluish-gray skin. They, are, however, not countershaded, as their backs are significantly lighter in shade, almost blending in with the ice above them. Their necks also have the light bluish-gray streaks and spots on them, bearing resemblance to the skin pattern of whale sharks, while their tails have three bands of the same color, similar to the tail of Kaikaifilu, a mosasaur also known to reside in the López de Bertodano Formation. The juveniles have the same skin pattern as the adults, albeit far lighter, with their stripes and spots more prominent, indicating that these features fade away with age, possibly because the skin patterns of the juveniles are meant to help camouflage them with the icy waters of Antarctica, similar to how several juvenile animals known today have different skin patterns compared to the adults in order to blend in with the environment more easily and evade danger as they grow.
The sun melting the ice sheet covering the seas of the 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. ”
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.[10] This sort of environment poses dangers similar to what several diving animals face today, as these sheets of ice may prevent air-breathing animals from reaching the surface to breathe in time.
The Morturneria pod on Prehistoric Planet is stated to have come from South America, a speculation supported by the fact that other Antarctic plesiosaurs like Aristonectes have also been found in Patagonia.
Paleofauna[]
“ 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. ”
The land areas of the López de Bertodano Formation has dinosaurs like Morrosaurus, hadrosaurs, and theropods, including five different birds and an indeterminate species only known from fragments. However, the López de Bertodano Formation is more known for the fauna of its polar sea. Morturneria lived alongside two other elasmosaurs, the similarly-sized Marambionectes as well as Aristonectes, one of the largest plesiosaurs ever discovered. Morturneria was once suggested to be a juvenile Aristonectes in 2003,[2] though this was refuted by studies in 2017 and 2019.[4][1] It is likely that all three plesiosaurs 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.
“ 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. ”
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. Despite being only 8 meters (26 feet) in length when fully grown, Morturneria would have been large enough to avoid being hunted by most of the animals it coexisted with. However, it would have been considered prey by several mosasaurs known to have lived in the region, from the 10-meter (33-foot) Kaikaifilu (a native tylosaurine portrayed 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. Ultimately, Morturneria and 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,[11] 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.
Hunting Tactics and Feeding Preferences[]
“ 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. ”
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. Prehistoric Planet depicts the elasmosaur as a benthivore, a bottom-feeding animal that obtains food near or on the bed of a body of water (in the case of Morturneria, this would be the sea floor of the López de Bertodano Formation). One of the tiny creatures that Morturneria may have fed on is Rotularia, a serpulid polychaete worm approximately 13 centimeters (5 inches) in length. Overall, the show's portrayal of Morturneria appears to be based on the gray whale, which also feeds by dragging its jaws through the sea floor, gulping in sediments to filter out crustacean prey.
Morturneria is not the first animal to have evolved specialized features for straining small prey. 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.[4]
Migratory Lifestyle[]
“ This pod has migrated nearly two thousand miles from South America to arrive here in time for spring. ”
Although it is only known from the López de Bertodano Formation, Morturneria is portrayed 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. ”
Based on fossil evidence, plesiosaurs are known to give live birth to a single large calf around a third of the mother's size.[12] 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.
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. ”
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.
Gallery[]
Morturneria (Adult) Concept Art by Gabriel Ugueto
Morturneria (Juvenile) Concept Art by Gabriel Ugueto
_concept_art_by_Gabriel_Ugueto.jpg "Morturneria (Adult) concept art by Gabriel Ugueto.jpg (431 KB)")
_concept_art_by_Gabriel_Ugueto.jpg "Morturneria (Juvenile) concept art by Gabriel Ugueto.jpg (410 KB)")