Episode 252 is all about Dacentrurus, A wide-hipped stegosaur from the Jurassic in England.
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In this episode, we discuss:
News:
- The Japanese “Mukawa dinosaur” now has an official name, Kamuysaurus japonicus source
- A new study shows how T. rex warmed up using a specialized area on top of its head source
- Brian Engh used this research to create an amazing thermal-image illustration source
- A marine turtle that got trampled by a sauropod in what is now Switzerland source
- For those keeping tabs, the Dinosaurs of Utah PDF has been updated to include more species of dinosaurs (now >115) source
- Here’s The Travel’s list of 10 dinosaur places to visit source
- Jurassic Park and Jurassic World memorabilia will be auctioned off in London source
- Crystal Palace dinosaurs had an open day on September 15 source
- Magic Leap recently launched a Dinosaur Kit, which lets you assemble dinosaur skeletons from scattered bones—if you have the $2,000+ headset source
- A maid of honor wore an inflatable T. rex costume to her sister’s wedding source
The dinosaur of the day: Dacentrurus
- Stegosaur that lived in the Jurassic in what is now England
- Not much known about its appearance
- Dacentrurus was robust
- Quadrupedal herbivore
- Had plates and spikes
- Some estimates as large as 33 ft (10 m) long and weighed up to 5 tons
- Had a wide pelvis, 4.9 ft (1.5 m) wide
- Very broad gut for a stegosaur
- Had short hindlimbs but long forelimbs
- Had similar proportions as Stegosaurus but the way the plates and spikes looked was different
- Probably had two rows of small plates on the neck and two rows of longer spikes on the tail
- Holotype has a small asymmetrical neck plate
- Some think it had a shoulder spike, but it’s unclear
- Originally was called Omosaurus
- The name Omosaurus was already used for a phytosaur, so it was renamed to Dacentrurus in 1902
- Joseph Leidy had named the phytosaur, Omosaurus perplexus in 1856
- In 1874, James Shopland from the Swindon Brick and Tyle Company told Richard Owen about fossils in the Swindon Great Quarry
- Owen sent William Davies to excavate the specimen, which was in clay. While trying to lift the clay piece, it crumbled
- Eventually it made its way to London (3 tons), and prepared by Caleb Barlow
- Omosaurus armatus was named in 1875, based on a skeleton found in the Kimmeridge Clay
- Described by Owen in 1875 (named Omosaurus armatus), which means “upper arm” and refers to its robust humerus
- The species name means “armed” in Latin, and refers to a large spike that Owen thought was on the upper arm
- Holotype includes a pelvis, dorsal vertebrae, sacrals and caudal vertebrae, right femur, left forelimb, partial fibula, partial tibia, right neck plate and left tail spike
- Many other species named, but no longer considered valid
- Other species that were named (and no longer considered valid) included Omosaurus hastiger (named by Owen, and which means “spike bearer” or “lance wielder” because Owen thought there were spikes on the wrist), Omosaurus durobrivensis (named by John Hulke in 1887 but was renamed as Lexovisaurus in 1956), Omosaurus phillipsii (named by Harry Seeley in 1893 based on a femur), Omosaurus vetustus (named in 1910 by Friedrich von Huene based on a femur, the name means “the ancient one” and is now Eoplophysis), Omosaurus lennieri (named in 1911 by Franz Nopcsa based on a partial skeleton found in 1899 in Normandy, France, but that specimen was destroyed in 1944, during the allied bombing of Caen)
- Only the type species, Dacentrurus armatus, is valid
- Name means “tail full of points”
- Frederick Augustus Lucas renamed Omosaurus armatus as Dacentrurus armatus in 1902 (name means “very sharp tail”)
- In 1915 Edwin Hennig renamed most of the Omosaurus species to Dacentrurus
- But many researchers still used the name Omosaurus until the 1950s
- First stegosaur discovered (before Stegosaurus)
- One of the best known stegosaurs from Europe
- Dacentrurus found in England, France, Portugal, and Spain
- Many stegosaur discoveries have been referred to Dacentrurus, as well as eggs found in Portugal
- Peter Galton in the 1980s referred all stegosaur fossils from Late Jurassic deposits in western Europe to Dacentrurus, but in 2008 Susannah Maidment limited Dacentrurus armatus material to the holotype, and found most named species to be nomina dubia
- In 2013, Alberto Cobos and Francisco Gascó described fossils found in Spain as Dacentrurus armatus (found two cervical vertebrae, one dorsal vertebra, and one caudal vertebra from one individual); this find shows intra-species variability of Dacentrurus
- Variability could be because of ontogeny, sexual dimorphism or individual pathologies
Fun Fact: The brain of Psittacosaurus changed shape dramatically as it grew up.
