Eustreptospondylus‭ (‬Well curved vertebra‭)

Short Info

Eustreptospondylus‭ (‬Well curved vertebra‭)

Phonetic : Yoo-strep-to-spon-di-lus.

Named By : Alick Walker‭ ‬-‭ ‬1964

Diet : Carnivore

Size : Estimated 4.6 – 7 meters long

Type of Dinosaur : Large Theropod

Type Species : E.‭ ‬oxoniensis (type)

Found in : England

When it Lived : Mid Jurassic, 165 million years ago

Eustreptospondylus (/ju:,streptoUspan’daIl@s/ yoo-STREPT-o-spon-DY-l@s; meaning “true Streptospondylus”) is a genus of megalosaurid theropod dinosaur, from the Oxfordian stage of the Late Jurassic period (some time between 163 and 154 million years ago) in southern England, at a time when Europe was a series of scattered islands (due to tectonic movement at the time which raised the sea-bed and flooded the lowland).

Eustreptospondylus skeleton (incomplete skull)Ballista at en.wikipedia, CC BY-SA 3.0, via Wikimedia Commons

The skeleton of an theropod was discovered by workers at the Summertown Brick Pit in Oxford, England in 1870. James Parker, a local bookeller, purchased the remains and brought them to Oxford Professor John Phillips. Phillips described the bones but didn’t name them. The remains were the largest skeleton ever found for a large theropod. Eustreptospondylus remains the largest Jurassic European large theropod skeleton. The skeleton was purchased by Oxford University in 1890. Arthur Smith Woodward reviewed it and referred the specimen to Megalosaurus Bucklandi. The skeleton was re-assigned to Streptospondylus cuvieri in 1906 and 1905 by Baron Franz Nopcsa. This species had been first described in 1842 by Sir Richard Owen, who used a now-lost vertebra from the Bathonian stage during the Jurassic period. This was done because Streptospondylus Altdorfensis, a type species from France, was clearly related to the skeleton. Nopcsa decided that all British material of this kind would be included under one Streptospondylus species. It was difficult to assign a fairly complete species to a species that was based on very poor remains. German Palaeontologist Friedrich von Huene added to this problem. He sometimes referred to the specimen Streptospondylus cuvieri, while other times he considered it to be a Megalosaurus species: Megalosaurus Cuvieri.

1964 saw Alick Donald Walker clarify matters by creating a separate species and genus for the Oxford specimen. Eustreptospondylus was the genus that meant “true Streptospondylus”. Streptospondylus, which means “turned vertebra”, is derived from the Greek words streptos and spondylus meaning “reversed”. This refers to the fact that the dorsal vertebrae are opisthocoelous in contrast to procoelous vertebrae found in crocodiles. Its specific name, “oxoniensis”, refers back to Oxford.

W. Parker found the holotype OUM J13558, which was made from claystone in the marine layer of The Stewartby Member of Oxford Clay Formation. This marine layer dates back to the Callovian stage during the Jurassic period (162 million years ago). It is a complete skull, missing the nasal bones, jugals and lower jaws. It is a subadult specimen. OUMNH J.29775, which is a left-ilium specimen, is the only Eustreptospondylus species ever referenced. The holotype was prepared in full and displayed in 1924 in an upright position. A new display made it possible to show the body horizontally in the beginning of the 21st century.

Oliver Walter Mischa Rauhut discovered that Eustreptospondylus was different from Magnosaurus in 2000. This is due to minor differences in the hip bones, which are more upwardly extending fusions of the pubic bone “feet”. He proposed in 2003 that they be one genus. Magnosaurus would then be called Magnosaurus Oxoniensis. Gregory S. Paul compared the species to Streptospondylus aldorfensis in 2010.

Nopcsa published the first detailed description of Eustreptospondylus material in 1906. Rudyard Sadleir, e.a. published a modern description in 2008. Rudyard Sadleir e.a. published a new description in 2008. This became the separate genus Piveteausaurus in 1977.

Source: Wikipedia