Dinosaur Brachylophosaurus canadensis, of Late Cretaceous, North America!

Earlier this year, a paper on a spectacular Edmontonsaurus “mummy” discovered in 1908 was published, revealing even more updates about the animal’s life appearance. Hadrosaur mummies (which are actually just exceptionally preserved fossils with large fossilized skin traces) are not completely new, or relegated to just this one fossil; multiple Edmontosaurus mummies have been found since 1908, as well as a Corythosaurus, and a Brachylophosaurus. This is probably attributed to the fact that hadrosaurs were numerous herd animals which traveled long distances, raising the chances that one among the millions would find itself dying in the exceptionally rare conditions needed for rapid dehydration and burial, followed by fossilization. All these amazing discoveries have allowed us to continue to unravel an almost complete picture of how these animals looked, using modern paleontology. Today we are looking at not Edmontosaurus, but it’s less famous cousin, Brachylophosaurus canadensis.

Brachylophosaurus canadensis is known from not only the original skull and skeleton named in 1953, but also a bonebed of over 800 specimens, and the afformentioned “mummy” affectionately nicknamed “Leonardo”, as well as a juvenile with some skin impressions, affectionately nicknamed “Peanut”. Brachylophosaurus had a horizontal, paddle-like bony crest that grew taller and wider with age, likely used to signal their maturity to potential mates. Their upper beak was wider than other hadrosaurs of the time, and they had cheeks which would have allowed them to chew as they browsed and grazed. While the mummy “Leonardo” is fossilized with his skin shriveled as one would expect a dehydrated corpse to have been, there are still indications that the base of his neck was heavily muscled. His diet seemed to consist of leaves, conifers, ferns, algae, liverworts, and flowering plants like magnolias.

It’s clear that this close relative of Maiasaura was a fairly common dinosaur in Late Cretaceous North America. Brachylophosaurus canadensis has been found in the Oldman Formation of Alberta, Canada, the Judith River Formation of Montana, USA, and possibly the Wahweap Formation of Utah, USA. Brachylophosaurus would have come across a wide variety of upland dinosaurs as they migrated through Campanian North America. They would have shared space with other hadrosaurs like Maiasaura and Corythosaurus, a variety of ceratopsians like Albertaceratops, Chasmosaurus russelli, Coronosaurus, Avaceratops, Judiceratops, Lokiceratops, Medusaceratops, and Mercuriceratops, thescelosaurids like Albertadromeus, pachycephalosaurids like Foraminacephale, Hanssuesia, and Colepiocephale, and avialans like Hesperornis. Brachylophosaurus would have also lived alongside small dromaeosaurs like Saurornitholestes and Dromaeosaurus, and could have been preyed on by large tyrannosaurids like Daspletosaurus and Gorgosaurus, as well as the giant alligatoroid Deinosuchus.

#Archovember Day 16 - Shantungosaurus giganteus

While hadrosaurs tend to be perceived as horse or cow-size, there were some intimidatingly huge members of the family. As the largest hadrosaur discovered so far, Shantungosaurus giganteus could reach 15 metres (49 ft) to 16.6 metres (54 ft) long and weigh an estimated 13 metric tons (14 short tons) to 16 metric tons (18 short tons). It lived in Late Cretaceous China, and would have filled a niche typically filled by sauropods in its ecosystem. As these dinosaurs have been found in a mass grave, it’s likely they also traveled in large, formidable herds. Shantungosaurus also had very large nostril holes which were probably covered by flaps of skin that could have inflated to amplify its calls.

Kritosaurus at a Salt Lick

Day 25- Velafrons

The site where the first and only specimen of Hadrosaurus was discovered is now a National Historic Landmark, known as the Hadrosaurus foulkii Leidy site. Hadrosaurus represents the first dinosaur species to be known from more than isolated teeth identified in North America.

Patreon request for @/rome.and.stuff (Instagram) - Secernosaurus koerneri

Secernosaurus was a member of a small group of hadrosaurs native to South America: the Austrokritosaurs, and it was the first of this group to be formally named. Most hadrosaurs lived in Laurasia (what is now North America and Eurasia) which was seperated from South America in the Cretaceous. The existence of Secernosaurus and its relatives suggests a land bridge temporarily formed between North and South America at this time, allowing North American kritosaurines to migrate South.

So far, only one specimen of Secernosaurus has been found. This fossil was previously thought to belong to a subadult, but recent study shows it was likely mature, or at least almost mature. This makes it the smallest of the Austrokritosaurs, only 4–5 metres (13–16 ft) long. Still a large animal, but rather small by hadrosaur standards!

Secernosaurus received its big screen debut in Prehistoric Planet’s second episode, however, the design of the animals were based off the better known Huallasaurus australis, as Huallasaurus was thought to be a species of Secernosaurus at the time.