Brontomerus Fact Sheet

21st February 2011

This fact-sheet is part of the Brontomerus Press Pack. See the main Press-Pack page for images and videos.

What the paper says

  1. Brontomerus mcintoshi is a newly-discovered sauropod dinosaur. The name Brontomerus refers to a genus (like Homo) and the full name Brontomerus mcintoshi refers to the species (like Homo sapiens). Since there is only one known species of Brontomerus, it usually suffices to use only the genus name. (Like all genus and species names, this is always set in italics.)
  2. Sauropod dinosaurs, known informally as "long-necks", include familiar animals such as Apatosaurus, Diplodocus, and Brachiosaurus.
  3. The fossil remains of Brontomerus come from a quarry in eastern Utah, USA.
  4. Brontomerus lived about 110 million years ago, during the Early Cretaceous Period.
  5. Other dinosaurs known from North America during the Early Cretaceous Period include Acrocanthosaurus, a giant predator similar in size to T. rex; Deinonychus and Utahraptor, two feathered dromaeosaurs or "raptors", similar to the raptors in Jurassic Park; Tenontosaurus, a cow-sized plant eater related to Iguanodon, and Gastonia, an early armored dinosaur that was also a plant-eater.
  6. The genus name Brontomerus means "thunder thighs", chosen because the shape of the ilium or hip bone shows that Brontomerus had extremely large thigh muscles.
  7. We don't know for sure why Brontomerus had such large thigh muscles. Possibly it used them to kick predators or rivals, and possibly they helped it travel over rough terrain.
  8. The species name mcintoshi honors Jack McIntosh, a retired Wesleyan physicist who has done a lot of important work on sauropods.
  9. The fossil remains of Brontomerus are incomplete but include many different parts of the skeleton, including vertebrae, ribs, a shoulder blade and a hip bone.
  10. The fossils of Brontomerus come from at least two individual animals, a pony-sized juvenile and a larger, elephant-sized animal that might have been a parent or relative of the smaller one. It is not unusual to find fossils of sauropods together in family groups.
  11. The Early Cretaceous Period used to be thought of as a sort of "dark age" in the middle of the Age of Dinosaurs, in that until recently few dinosaurs were known from that period. Apatosaurus, Diplodocus, Allosaurus and Stegosaurus all lived earlier, in the Late Jurassic Period; and T. rex, Triceratops, and most of the duckbills and armored dinosaurs lived later, during the Late Cretaceous Period.
  12. In the last two decades we have learned much more about the Early Cretaceous Period because paleontologists have sent more of their time searching for fossils in rocks from that period. These expeditions have led to the discovery of many new dinosaurs and other extinct animals.
  13. It is not unusual for new dinosaurs to be discovered even in very well-studied areas like North America. Although the first dinosaurs were named almost 200 years ago, more than half of all known dinosaurs have been discovered in the last 30 years.

What the paper does NOT say

  1. We do not say: Brontomerus was the biggest dinosaur.
    Fact: The larger of the two individuals was about the size of an elephant, which is small for a sauropod, but it might not have finished growing when it died.
  2. We do not say: The two individuals of Brontomerus for which we have fossils are a mother and its baby.
    Fact: That is a possibility, but we have no way of proving or disproving it.
  3. We do not say: The smaller individual of Brontomerus was a hatchling.
    Fact: Based on growth patterns in other sauropods, the smaller individual of Brontomerus was probably several years old when it died.
  4. We do not say: Sauropods practiced parental care.
    Fact: Sauropods buried their eggs in small nests and probably did not care for the hatchlings at all. Juvenile sauropods did not join herds with adults until a few years after they hatched.
  5. We do not say: Brontomerus is the first dinosaur or the first sauropod discovered from the Early Cretaceous of North America.
    Fact: Many dinosaurs are known from that time, including many other sauropods. This is mainly because of successful dinosaur-hunting expeditions in the 1990s and 2000s.
  6. We do not say: Brontomerus lived at the same time as T. rex.
    Fact: Although they both lived in the Cretaceous, nearly 50 million years separated them.
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