Paleontologists writing in the journal Paludicola report the discovery of exceptionally well-preserved skull and skeletal remains of the elasmosaurid plesiosaur Zarafasaura oceanis, the most complete specimen of this species ever described.

Plesiosaurs (‘near to lizard’ in Greek) are an intriguing group of extinct marine reptiles that roamed the vast seas of the Triassic, Jurassic and Cretaceous periods from 235 to 66 million years ago. Their fossils have been found on every continent on Earth, with key discoveries made in Australia, Europe and North America.

There are several different families of plesiosaurs, including the Elasmosauridae, Microcleididae and Plesiosauridae.

Zarafasaura oceanis belongs to the family Elasmosauridae. The generic name Zarafasaura derives from zarafa, an Arabic word for ‘giraffe,’ and saurus, Greek for ‘lizard.’ The specific name means ‘daughter of the sea’ in Latin.

Paleontologist Dr Peggy Vincent from the National Museum of Natural History in Paris, France, and her colleagues first described the species in 2011 from incomplete skull remains found in Morocco.

Zarafasaura oceanis was approximately 23 feet (7 meters) long and lived around 72 to 66 million years ago.

“Remains of Zarafasaura oceanis have all been collected from what is now Morocco, Africa. It lived during the last stage of the Cretaceous Period, the Maastrichtian,” said study lead author Dean Lomax, assistant curator of paleontology at Doncaster Museum and Art Gallery in England.

“Previously only two specimens, an isolated skull and a complete mandible (lower jaw), were described for Zarafasaura oceanis. As the postcranial remains were missing the general aspect and understanding of Zarafasaura oceanis was unknown,” added study co-author William Wahl, a paleontologist with the Wyoming Dinosaur Center and the Big Horn Basin Foundation in Thermopolis, Wyoming.

The new, well-preserved specimen of Zarafasaura oceanis was unearthed in a phosphate mine near the Moroccan city of Oued-Zem.

“The recovery of complete or articulated plesiosaur fossils in Africa is fairly low, with only a handful of well preserved specimens known. Many specimens collected from Morocco are very fragmentary and their true taxonomic identification is often extremely difficult, to impossible,” explained Dean Lomax, who is also a visiting scientist at the University of Manchester’s School of Earth, Atmospheric and Environmental Sciences.

“This new discovery describes a skull associated with a partial skeleton, enabling a greater understanding of the animal. Perhaps most importantly as the new specimen has numerous elements preserved e.g. limbs, vertebrae, pectoral and pelvic material, it is possible that isolated and less complete plesiosaur remains recovered from the Morocco area may potentially be identified, using the new specimen,” he said.

The specimen of Zarafasaura oceanis from Oued-Zem is now mounted on display at the Wyoming Dinosaur Center.

“We hope this new specimen allows for some interest in previously unnoticed Moroccan specimens laying about in collections,” William Wahl concluded.

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Bibliographic information: Dean R. Lomax and William R. Wahl. 2013. A new specimen of the elasmosaurid plesiosaur Zarafasaura oceanis from the Upper Cretaceous (Maastrichtian) of Morocco. Paludicola 9 (2): 97-109

* The authors would like to thank the artist Nobumichi Tamura for the first-ever reconstruction of Zarafasaura oceanis.