Episode 9 is about Dreadnoughtus, one of the largest dinosaurs to have ever lived, and was so big it had nothing to fear.
You can listen to our free podcast, with all our episodes, on iTunes at:
In this episode, we discuss:
- The dinosaur of the day: Dreadnoughtus
- The name Dreadnoughtus comes from an old English word that means “fear nothing”
- The dinosaur was so big, there was probably nothing that could have attacked it; Dreadnoughtus may have been the biggest dinosaur ever
- The full name of the species, Dreadnoughtus schrani, is based on the name of the big battleships in the 1900s, as well as Adam Schran, who helped fund the research
- Dr. Kenneth Lacovara, from Drexel University, discovered Dreadnoughtus during excavations between 2005-2009, in the Cerro Fortaleza Formation in the Santa Cruz Province, Patagonia, Argentina
- In 2014 news of the discovery spread. In addition to being giant, the Dreadnoughtus was one of the most complete skeletons found. Researchers found about 45% of the complete skeleton (most of the bones, like the ribs, were hollow). This will help scientists determine how it lived, its bone strength, how it helped itself up, as well as how big it was
- Dreadnoughtus was about 85 feet long, 30 feet tall, and weighed 65 tons, which is the equivalent of 12 elephants or 9 times the weight of a T-rex
- Blue whales are still the largest animals to have lived (on land and in water); they grow to 150 tons
- After analyzing the bones, scientists concluded that the Dreadnoughtus skeleton they found was still growing when it died. It probably died young due to a catastrophic flood
- Researchers were able to measure the femur and humerus (the “gold standard” for calculating the mass of four-legged animals) to determine the 65 ton weight estimate. According to paleontologist Kenneth Lacovara, no other dinosaur measured that way was as big (Argentinosaurus only has a partial skeleton, so estimates on its weight vary greatly)
- Because Dreadnoughtus was so big, and it was found in a remote location, it took Lacovara and his team four summers to excavate.
- They used mules to help get the bones to a truck. In 2009, the team used an ocean freighter to move Dreadnoughtus to Philadelphia to prepare the fossils and analyze them. Eventually the fossils will be given to the Museo Padre Molina in Rio Gallegos, Argentina
- Because of the completeness of the skeleton, scientists may be able to model the Dreadnoughtus‘ breathing, figure out its blood pressure and exactly how much food it had to eat, and determine proportions and shapes of giant sauropods
- Dreadnoughtus had a shorter, more muscular tail (about 30 feet long) and longer neck than expected. The neck was 37-feet long, and probably allowed Dreadnoughtus to stand in one place to eat. This efficiency was important, since it had to consumer half a ton of food every day
- Scientists found a single cylindrical tooth, about one inch long. Dreadnoughtus had rows of these teeth, which they used to strip vegetation and swallow without chewing. Lacovara said their stomachs were larger than a draft horse, so the vegetation probably stayed in their stomachs for months.
- Dreadnoughtus had longer forearms than other Titanosaurs (its clade or group) but they are not much longer than its hind limbs, so it probably held its neck more horizontally.
- Dreadnoughtus‘ tail had unique characteristics. The first vertebrae had a ridge on its ventral surface, called a keel.
- Also, part of its respiratory system was in the bases of the neural spines in the first third of the tail, which had cavities caused by contact with air sacs. According to Lacovara, body weight of modern animals correlates to internal body temperature. But at 65 tons, body temperature would be much higher than the temperature that cooks meat, so the air sacs helped Dreadnoughtus fan themselves on the inside.
- The long neck and tail gave Dreadnoughtus more surface area per volume, which would have also helped Dreadnoughtus manage its body heat.
- The neural spines in Dreadnoughtus‘ tail had distinct ridges. Like modern animals with tails, such as crocodiles, Dreadnoughtus had bones below its vertebrae called chevrons. They bones connected in a “Y” shape
- Lacovara and his team made laser scans of all the bones found, and they used 3D imagery to figure out how it moved.
- The team also used 3D printers to create models at one-tenth scale. All the 3-D scans are available for free as PDF files, on Figshare
- Dreadnoughtus is part of the Titanosaur group. Titanosaurians is a group of sauropods, very large herbivores, that lived during the last 30 million years of the Mesozoic Era. Some titanosaur species are the largest land-living animals discovered, but in many cases, scientists have found incomplete fossils
- The name Titanosaur came from the Titans of Ancient Greek mythology
- The family, Titanosauridae, was named after Titanosaurus, an incomplete fossil (only a partial femur and two incomplete caudal vertebrae) found by Richard Lydekker in 1877. Some scientists think there is not enough information for Titanosauridae to be a genus
- Titanosaurs were the last group of sauropods. They lived about 90 to 66 million years ago and were the dominant herbivores. They replaced other sauropods, like diplodocids and brachiosaurids
- Titanosaur fossils have been found on all continents, including Antarctica. The most titanosaurs lived in the southern continents, which was then part of the supercontinent Gondwana.
- Compared to other sauropods, Titanosaurs had small heads. Their heads were also wide, with large nostrils, and crests formed by nasal bones
- Titanosaurs had spoon-like, or peg or pencil like teeth that were very small
- Titanosaurs were not picky eaters. They had a broad diet which included cycads and conifers, as well as (surprisingly) palms and grasses, such as the ancestors of rice and bamboo (evidence that dinosaurs and grasses evolved together)
- They tended to have average length necks, at least for sauropods, and whip-like tails, but not as long as the Diplodocus tail
- Titanosaurs also had slimmer pelvis’ compared to some sauropods, and wider chests, which gave them a broader stance (and they left broader tracks)
- They had stocky forelimbs that were usually longer than their hindlimbs, and they had solid back bones instead of hollowed out back bones
- But they also had a more flexible spinal column, so they could probably move better and rear up
- Scientists have found from skin impressions that Titanosaurs had small, bead-like scales around larger scales. And one species, Saltasaurus, even had bony plates, like an ankylosaurus
- Titanosaurs, such as Rapetosaurus, may have used their osteoderms to store minerals during droughts
- Fun fact: Scientists used to theorize that some dinosaurs had two brains, and the second brain was in their butt
Share your thoughts