The Big Dinosaur Podcast

Episode 231 is all about Haestasaurus, a sauropod whose arm was originally thought to be from a carnivorous marine reptile.

We also interview Steve Brusatte, Paleontologist at The University of Edinburgh. Before moving to the UK he spent several years at the American Museum of Natural History. He is also the “resident paleontologist” for BBC’s Walking with Dinosaurs and author of the book The Rise and Fall of the Dinosaurs.

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In this episode, we discuss:

News:

• A new hadrosauroid, Gobihadros, was described from a complete skeleton and skull source
• A juvenile T. rex is for sale on eBay, stirring up quite a bit of controversy source
• A new ankylosaur has been announced in Hillsboro, Texas source
• A hadrosauroid from Hokkaido is going on display in the National Museum of Nature and Science in Tokyo source
• In Japan, an 18-year-old high school student Yuuki Kadoguchi found a 90 million year old tyrannosaur tooth source
• A new presentation details the tracks from the St. George Utah dinosaur track site source
• The Montana bill making fossils part of a property’s surface rights was signed by governor Steve Bullock source

The dinosaur of the day: Haestasaurus

• Sauropod that lived in the Early Cretaceous in what is now England
• Type species is Haestasaurus becklesii
• Only forelimb is known (humerus, ulna, radius)
• Parts of the skin were also preserved (first dinosaur specimen integument found), and had hexgonal scales that decreased in size, maybe toward the elbow, and they look a lot like skin impressions in other, later sauropod finds
• Sauropod, so quadrupedal, herbivorous, had a long neck
• Complicated history of this sauropod
• Richard Owen named Cetiosaurus in 1841, based on sauropod fragments found around England. For a long time, he thought these fossils were all from large, carnivorous marine reptiles, and were not dinosaurs. He named four species of Cetiosaurus
• Melville reclassified most of these fossils as Iguanodon, except for four caudal vertebrae and three chevrons that he said were a new species, Cetiosaurus conybeari
• In 1850, a large right humerus was found near the site where the Cetiosaurus conybeari vertebrae were found, and Mantell named it Pelorosaurus conybeari, based on the humerus, caudal vertebrae, and chevrons. He found the humerus to be robust and straight, and that there was a medullary cavity, and said Pelorosaurus was probably a dinosaur, not a marine reptile
• Owen disagreed, and instead called the caudal vertebrae and chevrons Cetiosaurus brevis, and used the name Pelorosaurus conybeari for the humerus
• Samuel Husband Beckles collected a block of sandstone in 1852 that was found near Hastings, which had a large forelimb and skin impressions. Gideon Mantell analyzed the forelimb and named it as a second species of Pelorosaurus, Pelorosaurus becklesii (in honor of Beckles), based on the humerus being shorter and more robust
• Not much written about this find. Richard Owen ignored it
• Fossil was part of Beckles’ private collection, then the British Museum of Natural History purchased it in 1891
• Richard Lydekker studied the fossils in the 1880s and 1890s and said Pelorosaurus conybeari could be a synonym of Ornithopsis. He also said the fossil for Pelorosaurus becklesii could be Cetiosaurus brevis or referable to Titanosaurus or be a new genus, and he erroneously said it came from the Isle of Wight, instead of East Sussex
• Othniel Charles Marsh named Morosaurus, a sauropod from the Late Jurassic Morrison Formation (now thought to be a junior synonym to Camarasaurus), and compared British dinosaur material with North America dinosaur material when he visited England in 1888. In 1889 he said that Pelorosaurus becklesii was referable to Morosaurus, based on similarities and limb proportions, and said the combination was Morosaurus becklesii
• Nicholson and Lydekker found that Cetiosaurus brevis, the caudal vertebrae of Pelorosaurus conybeari, and Morosaurus becklesii were the same, and named them all Morosaurus brevis
• However, Morosaurus is no longer considered to be a valid taxon, and the diagnostic characters for it are vague and common to many sauropods
• In 1932 Friedrich von Huene found that the caudal vertebrae of Cetiosaurus brevis was part of Megalosauridae and that the humerus of Pelorosaurus becklesii was different from Pelorosaurus conybeari (different proportions), and he referred to it as “Gen. (?) becklesii” (question mark shows it to be an unknown genus), and it seems he thought it was closely related to Camarasaurus
• Around 1990 John McIntosh found that Pelorosaurus was a valid brachiosaurid with a few species, such as Pelorosaurus conybeari and Pelorosaurus mackensoni, but he did not consider Pelorosaurus becklesii to be Pelorosaurus, and instead thought it was Sauropoda incertae sedis (uncertain type of sauropod), based on the limb proportions
• Some thought it was a titanosaur because of the robustness of the forelimb, though not everyone agreed
• Several scientists have said that Pelorosaurus becklesii is a distinct taxon, but didn’t give it a new name because the holotype is pretty incomplete, and it’s been hard to establish autopomorphies
• Then in 2015, Paul Upchurch, Philip Mannion, and Michael Taylor found that Pelorosaurus becklesii was different enough from Pelorosaurus conybeari and named it as a new genus, Haestasaurus becklesii
• Humerus is pretty complete and unbroken, ulna is complete but was broken and repaired, radius was mostly complete but was broken in three places that were repaired
• The team in 2015 found five autapomorphies, including having a robust ulna with a slender radius and having two small vertical ridges on the humerus
• Not certain where Haestasaurus is phylogenetically. Could be a basal macronarian (the most basal), could be a derived titanosaur
• Name “Haesta” is the name of a pre-Roman chieftan, and his people settled in the area of Hastings and gave Hastings its name (near where the dinosaur was found)
• Mentioned in The Top 10 Dinosaurs of 2015 book

Fun Fact: There were large tyrannosaurs in the Eastern US during the latest cretaceous, but they may not have been T. rex.