Adalatherium (Crazy Beast) is an extinct gondwanatherian mammal that lived in the Maevarano Formation of the Mahajanga Province (known as "Majunga" in French) in northwest Madagascar, 70 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.
Out of all the Mesozoic mammals known so far, Adalatherium is the fourth largest in terms of mass (1.78 - 5.22 kilograms, or 4 - 11.51 pounds),[2] with this likely being the result of island gigantism. This gondwanatherian, which grew to be as large as a cat or badger, was only exceeded by Vintana sertichi (9.1 kilograms, or 20 pounds),[5] a groundhog-like sudamericid mammal that lived alongside Adalatherium in the Maevarano Formation, Repenomamus giganticus (12 - 14 kilograms, or 26.5 - 31 pounds),[6] a gobicodontid that fed on small and juvenile dinosaurs in the Yixian Formation of China more than 50 million years before Adalatherium, and Patagomaia chainko (14 kilograms, or 31 pounds),[7] a (possibly gondwanatherian)[8] mammal from the Chorrillo Formation in Argentina.
The front of Adalatherium's skull is the second discovered head of any gondwanatherian mammal (the first being that of Vintana). It has more foramina (openings) than the skull of any other mammal except the Argentinian cladotherian Vincelestes. Overall, Adalatherium has the most complete skeleton of a Gondwanan Mesozoic mammaliaform currently found, and includes the only postcranial material and ascending ramus (part of the mandible) of the dentary known for any gondwanatherian.[2]
“ Her eyesight, like that of many burrowing animals, is not very sensitive. She relies instead on her acute hearing, and if she hears something that might be dangerous, she stays perfectly still. Trouble avoided. She returns to searching in the Earth for roots and seeds. ”
Similar to rodents today, Adalatherium was equipped with continuously-growing front teeth, a case of convergent evolution. Its rear teeth are unique compared to those of other mammals, for each one has a diamond-shaped ridge running around the outside, interlocking with the opposing tooth on the other jaw. This unusual dentition indicates that it was a herbivore. With its unusually-bowed leg bones, strong back muscles, and enlarged claws, Adalatherium was likely a fossorial (burrowing) animal, able to use the claws of its robust arms to dig through the soil to form or enlarge new or preexisting burrows, or uncover roots and seeds to feed on.[2][4]
Prehistoric Planet's Portrayal[]
Fitting for its size, Prehistoric Planet depicts Adalatherium as quite a stocky mammal, covered in short fur that is light brown over the head and back, with the underbelly and neck colored light tan. The cubs hatch from their eggs naked and blind, and rely on milk produced from modified sweat glands on their mother's belly.
“ The island of Madagascar has been separated from the African mainland for 80 million years, so long that most of its animals are now very different from any to be found elsewhere. ”
Adalatherium lived 70 - 66 million years ago in the Maevarano Formation in the Mahajanga Province of Madagascar. The Maevarano Formation is recognized as an alluvial plain where the discharge of rivers fluctuate. The area is also believed to have had reddish soil, with floodplains that supported vegetation able to grow in the relatively dry climate. The region, at times semi-arid (like it is today), at times undergoing strong dry and wet seasons, was eventually claimed by rising sea levels that pushed the shoreline back. This may or may not have been the result of the Cretaceous-Paleogene Extinction Event, a catastrophe that wiped out three-quarters of life on Earth.
Paleofauna[]
“ Simosuchus is not the only evolutionary oddity to thrive on Madagascar. The island is also home to another group of very unusual animals... Mammals. ”
As with many Maastrichtian formations, the Maevarano Formation is known for its non-avian dinosaurs. Because of the harsh conditions in the area and the fact that it is completely isolated from other landmasses, some of these animals evolved certain adaptations and adopted certain behaviors to survive. Some, like the titanosaur Rapetosaurus, may have cooled down by bathing in mud (as depicted in the third segment of Swamps), and, like many dinosaurs, relied on the r-selection strategy, which involves spawning quick-growing juveniles en masse and leaving them to survive on their own, for many are expected to die while the numerous hatchlings which make it to adulthood bring forth the next generation to continue the cycle.[9][10] Others, like Masiakasaurus and Majungasaurus, grew slowly (8 - 10 years for Masiakasaurus, 20 years for Majungasaurus) in order to reduce the cost of maintaining and nourishing themselves.[11][12]Masiakasaurus has procumbent (forward-projecting) heterodont (differently-shaped) front teeth that helped it grip prey more easily,[13] and Majungasaurus, the apex predator of the region, is recognized as one of the few dinosaurs confirmed to have engaged in cannibalism.[14]
These same factors do not affect only the non-avian dinosaurs, for other inhabitants of the Maevarano Formation also became peculiar in their own right. Although nothing is known of the mating, reproductive, and juvenile-rearing habits of Beelzebufo (one of the largest frogs that ever lived, capable of eating small and juvenile dinosaurs), it has been suggested that it could be as complex as anurans today (e.g. giving birth to live young, skipping the tadpole phase, and even employed complex mating and parental strategies).[DN 1][DN 2] The notosuchian crocodylomorph Simosuchus is a dog-sized herbivore with a compact build,[15][16] and, though not a specialized digger, may have been capable of burrowing to an extent to escape predators as well as the unforgiving dry and wet seasons of Madagascar.[15][DN 3] Lastly, the mammals of Madagascar, like Adalatherium itself and the slightly larger Vintana, may have attained their large sizes due to the phenomenon of insular gigantism (which also affected other animals in the series like Imperobator and Hatzegopteryx), and, as described earlier, Adalatherium possessed traits that set it apart from most mammals, like its interlocking rear teeth.[2][4] As depicted on Prehistoric Planet, it may have even been one of the first to have mammary glands to nourish its offspring with milk.
“ After 150 million years, the dinosaurs were wiped out by a massive meteor strike. In their place, mammals became the dominant life on planet Earth, as they still are today. ”
Despite being one of the largest mammals of the Mesozoic Era, Adalatherium is still a very small animal and therefore a quick snack for any predator that encounters it. Hence, it must be alert at all times to evade hunters like Majungasaurus, Masiakasaurus, the paravian theropod Rahonavis, and the constricting serpent Madtsoia madagascariensis, which can grow up to the size of a common anaconda. Eventually, Adalatherium and most of the inhabitants of the Maevarano Formation perished due to the Cretaceous-Paleogene Extinction Event 66.043 million years ago,[17] a catastrophe that wiped out three-quarters of all life on Earth, including all non-avian dinosaurs, pterosaurs, plesiosaurs, mosasaurs, and other unique forms of life, like Simosuchus, one of the last known herbivorous crocodylomorphs. Mammals, along with many other groups of animals, also suffered great losses during the event, but those that survived went on to ultimately claim the Earth in the place of the non-avian dinosaurs.
Parental Habits[]
“ She spends most of her waking hours searching for food. At the end of the tunnel, there are eggs, potentially a rich source of protein. But she doesn't eat this particular clutch. These are her own eggs, and this is her burrow. ”
Prehistoric Planet depicts Adalatherium as a caring mother keeping her eggs safe in a hidden burrow. As the cubs of her litter (depicted in the show as reaching at least ten) grow, so do their appetites, so until the day that they can live independently, the mother has to exert more and more effort in finding food to feed herself and thus provide her cubs the milk they need. Since Adalatherium is a burrowing animal, it has poor eyesight, compensated by acute hearing. In the event that it comes across a threat, it tries to avoid getting noticed by staying completely still. And should the mother feel that her litter is living in an area full of danger, rather than continuing to risk living in the area, she and her litter would resort to moving somewhere else. The cubs, born from small eggs, grew rapidly and relied on their mother's milk for an extended period of time. They are also shown to be quite playful, clingy to their mother, and sleepy. Whenever their mother leaves to find food, the cubs stay within the safety of the burrow.
“ The eggs are starting to hatch. The hatchlings' eyes have not yet opened, but, instinctively, they head towards their mother to feed on milk. She produces it from modified sweat glands on her belly, and, for now, it's all the food they need. ”
The idea that Adalatherium (and other gondwanatherians) laid eggs is a matter of debate. Based on the idea that multituberculates (which are considered close relatives of the gondwanatheres) might have laid eggs, Adalatherium was portrayed on the show as an egg-laying mammal.[DN 4] However, in a study published in 2022, just a year before the release of Season 2, an analysis of multituberculate bones suggested that multituberculates did not lay eggs, though the show's portrayal is not fully invalidated since it is still possible that gondwanatheres were different and not even closely related to multituberculates.[DN 5]
In the fourth segment of the Islands, as the afternoon sun shines down on Madagascar, an Adalatherium travels across the land, making her way to a burrow obscured by the exposed roots of a tree. She comes across eggs within the den, and, sniffing them, she lies down and sleeps next to them, for these eggs are her own. The eggs hatch, and the juveniles, though born blind, sense where their mother is and feed on milk produced by modified sweat glands on her belly.
“ Two months later, and the cubs have more than quadrupled in size. To produce enough milk for them, their mother must herself eat a great deal. So, every night, she has to leave the safety of the den in order to feed. ”
In two months, the ten cubs have grown to more than four times their size, though still reliant on their mother's milk, so every night, she leaves the burrow to feed in order to be able to produce this nourishment. In the darkness, a serpentine figure watches her as she looks for sustenance, navigating the terrain decently, her acute hearing serving as compensation for her poor eyesight. She comes across the same injured, half-blind female Majungasaurus that tried and failed to hunt some Simosuchus earlier in the day. In the presence of danger, the Adalatherium stays still to avoid getting noticed. Fortunately for the mammal, the theropod remained unaware of her presence, the Majungasaurus briefly sniffing the air before wandering off to continue looking for prey. When she is sure the predator is no longer around, she returns to digging the soil for roots and seeds to feed on.
“ The cubs are growing fast, and so are their appetites. The female is now having to search almost nonstop for food, so her cubs are left unguarded for hours at a time. ”
In the morning, after they suck milk from her yet again, the mother leaves her cubs in the burrow to search for food. Just then, a Masiakasaurus, also seeking food, pokes its narrow head and long neck through holes that could potentially contain a meal. However, just as the Masiakasaurus stalks around the tree roots just outside the burrow, close to discovering the oblivious cubs, the snake from the night before lunges at the theropod's throat, subduing its victim with its muscular coils.
“ Madtsoia, a snake nearly 25 feet long, squeezes its prey to death. This neighborhood has now become rather dangerous. As night falls, the mother leads her young out of the burrow for the very first time. For now, at least, they must stay close together. ”
Having bore witness to one potential predator kill and feed on another, just outside her burrow, the returning Adalatherium enters her den, settling down and letting her babies suckle on her. Deciding that the area has become too unsafe to live in, she moves out of the burrow and sets out for a better place to live in, her ten cubs following close behind. One of the cubs briefly looks back and finds the Madtsoia resting on a fallen tree branch, staring back at it. With this, the Adalatherium cub turns back around and continues to follow its mother as they leave the area.
Subject The other weird and wonderful creatures that lived alongside the dinosaurs, from Beelzebufo, marine reptiles, and pterosaurs, to their successors, mammals.
Experts Dr. Darren Naish, Dr. Marc Jones, Dr. Mark Witton, Professor Anjali Goswami
Subject The other weird and wonderful creatures that lived alongside the dinosaurs, from Beelzebufo, marine reptiles, and pterosaurs, to their successors, mammals.
Experts Dr. Darren Naish, Dr. Marc Jones, Dr. Mark Witton, Professor Anjali Goswami
Footage of Adalatherium is used in the last portion of this Uncovered segment, dedicated to discussing the animals that lived alongside the dinosaurs. While many of the impressive creatures that lived alongside the dinosaurs (from massive frogs like Beelzebufo to the marine reptiles that dominated the sea and the pterosaurs that ruled the skies) were not like anything alive today, there were also some other animals that might seem a little bit more familiar.
The Late Cretaceous, though mostly remembered for the dominance of the dinosaurs, was also filled with mammals of all sorts, some of which lived in the water like beavers, critters that ran in the trees, gliding creatures, and even digging, burrowing animals like Adalatherium. Some of these mammals have even evolved for a nocturnal lifestyle, which helps them avoid some of the dinosaurs that lived alongside them.
“ They evolved a lot of different tools to help them survive during that period. Fur, being warm-blooded, even evolving big brains and sensory structures that allow them to see at nighttime. In fact, we may have dinosaurs to thank for the way mammals look today. ”
― Anjali Goswami, Research Leader, Palaeobiology
And as the reign of the dinosaurs, spanning more than 150 million years, was finally ended by a massive meteor strike, mammals took over as the dominant life on Earth, as they still are today.
