Rapetosaurus (Rapeto Lizard, named after a giant deity in Malagasy folklore responsible for creating various features of the land) is a genus of titanosaurian sauropod dinosaur 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.
Much like its Mongolian relative Nemegtosaurus, Rapetosaurus is a medium-sized titanosaur, merely 16.5 meters (54 feet) in length and around 10.3 metric tons (11.35 short tons) in mass.[3] Prehistoric Planet brings up a weight of 70 metric tons (77 short tons),[2] though given the animal's modest size, it unlikely weighed as much as a Mongolian Titan (which is stated to have the same weight in Deserts). Instead, this may be referring to the combined weight of all six individuals shown taking a mud bath, implying that each one weighs almost 12 metric tons (13.23 short tons).
Growth[]
Microscopic analysis and CT scans indicate that Rapetosaurus can grow quickly, around the same rate as an elephant, though it still would have taken them several years to reach adulthood, and several more to complete their lifespan should it not be prematurely ended. The fossil of a juvenile Rapetosaurus, estimated to have been 3.4 kilograms (8.8 pounds) when it hatched, grew to be around 40 kilograms (88 pounds) in a few weeks.[4][5]
Prehistoric Planet depicts Rapetosaurus with an earthly brown color with a few streaks in a lighter shade. Osteoderms cover the animal's back, a feature based on evidence of such armor being found on other titanosaurs. Unlike some of the titanosaurs on Prehistoric Planet, Rapetosaurus is correctly depicted without thumb claws (for most - but not all - titanosaurs had specialized hands that lacked fingers). An assortment of tools were used to portray its movements in a muddy riverbed, including a plastic bin to simulate its feet.[DN 1]
“ His pools now lie beneath 70 tonnes of sauropod. Time is short. Female devil toads will only mate at the start of the rainy season. He needs a new pool. ”
A herd of six Rapetosaurus was featured in the third segment of Swamps, visiting a half-dry river bed to take a mud bath in it, disturbing the mating efforts of a male Beelzebufo in the process. As with all the sauropods that appeared in the first and second season (except for the Nemegt Forest Titanosaur), footage of Rapetosaurus is used in the Uncovered segment "How Did Dinosaurs Get So Big?"
“ In Northern Madagascar, conditions are already changing. The first rain in months is reviving the parched land. As pools and channels refill, the animals return. ”
Rapetosaurus 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.
Social Behavior[]
As with most sauropod depictions, Prehistoric Planet shows Rapetosaurus as a herding animal, albeit to a slightly lesser degree than other sauropods. The third segment of Swamps shows a small herd of six individuals traveling together. The herd likely only consists of adults, indicating that, like most sauropods, Rapetosaurus was an r-strategist, an animal that spawns many offsprings and provides them little or no parental care, with many expected to die while the fitter (or at least, luckier) ones surviving to adulthood to bring forth the next generation. Evidence of this can be seen via the remains of a 40-kilogram (88-pound) Rapetosaurus, which, based on bone remodeling, is believed to be capable of surviving on its own. The juvenile died when it was around 39 - 77 days old, likely due to thirst and starvation brought upon by the harsh droughts and conditions of the Maevarano Formation.[4][5]
While sitting in a pool, calling for a mate, a male Beelzebufo is disturbed by a curious Rapetosaurus
Despite their large size (being one of the three titanosaurs in the area, they dwarf most of the other creatures in Madagascar), Rapetosauruses are shown to be quite curious of other animals, most of which are smaller than them. This interest can be irritating for some creatures like Beelzebufo, with one male losing his temper and forcing the giant sauropod away by leaping and hissing at it. This reflects how, even today, large animals may unintentionally disrupt the mating and breeding activities of frogs and toads.[DN 2]
Hygiene and Keystone Species Status[]
“ Luckily for him, there's one thing that Rapetosaurs enjoy even more than wallowing in mud, and that is food. The hungry herd moves on, although not without leaving something useful behind. Dozens of giant footprints, full of water. Perfect for a Beelzebufo to continue his quest for a mate. ”
As with elephants and other large animals today, Rapetosauruses are depicted relieving themselves with mud baths to clear away parasites and keep themselves cool. In the process, however, as they wallow and leave behind their footprints in the mud, they end up reshaping their landscape, modifying and even creating new habitats for smaller creatures like Beelzebufo. Rapetosaurus essentially appears to be a keystone species, a type of creature that plays a great effect on its natural environment, befitting given how Rapetosaurus is named after "Rapeto", the creator of the island of Madagascar according to Malagasy folklore.
