Cetiosaurus
| Key | Value |
|---|---|
| Name Meaning | “whale lizard” |
| Location | United Kingdom (England), France (?) |
| Time Period | c. 168 million years ago (Middle Jurassic) |
| Length | 52 ft (16 m) |
| Weight | 12 tons (11,000 kg) |
| Locomotion | Quadruped |
| Diet | Herbivore |
| Described | 1841 (Owen) |
| Geological Formation(s) | Rutland, Forest Marble |
| Valid Species | Cetiosaurus oxoniensis (type) |
Phylogeny: Dinosauria > Saurischia > Sauropodomorpha > Plateosauria > Massopoda > Sauropodiformes > Sauropoda > Gravisauria > Eusauropoda > Cetiosauridae
Overview: One of the most completely known sauropods ever found in England, the earliest known fossils of this creature were recovered in the 1820’s. This was before the concept of sauropods, or even of dinosaurs as a distinct clade, became widely known. Cetiosaurus was formally established as a genus in 1841 by Richard Owen, one of England’s most prolific naturalists. This was only a year or so prior to Owen’s establishment of the Dinosauria, but even then, he didn’t recognize this genus as a dinosaur. He believed Cetiosaurus to have been a giant, ocean-going animal similar to modern crocodiles, hence its generic name – the “whale lizard”. More complete fossils would be described in the 1860’s, revealing its dinosaurian nature, but its status as a sauropod wasn’t cemented until a series of discoveries made a decade or so later (largely in the United States). Many sauropods from Europe and elsewhere would be referred to this genus, incorrectly, as additional species.
Cetiosaurus is the namesake of the family Cetiosauridae, classified as one of the earlier branching groups within the larger clade Eusauropoda. They were more derived than genera like Vulcanodon, but less so than the mamenchisaurids, turiasaurs, and neosauropods (the group that contained the diplodocids, brachiosaurids, and titanosaurs). Some speculate cetiosaurids and mamenchisaurids may’ve been related in some way. Given its status as a basal eusauropod, Cetiosaurus had a myriad of fairly “primitive” traits. Growing to be about sixteen meters long, it was large, but nowhere near as big as some later sauropods. Patagosaurus may’ve been a close relative, though there is much debate over which sauropods really did belong to the Cetiosauridae. Cetiosaurus fossils are known from a couple different Middle Jurassic-aged geological formations in England. It probably lived alongside stegosaurs and some large theropods, potentially including the famous Megalosaurus.