Researchers writing in the on-line, open-access journal PLOS One have described the most complete plesiosaur skull found to date from sub-Saharan Africa. The skull and post cranial fossil material reported upon comes from the Upper Cretaceous Mocuio Formation exposures located at Bentiaba in the Namibe Province of Angola.

The fossils represent another specimen of the elasmosaurid Cardiocorax (C. mukulu) one of just six valid plesiosaurian taxa known from the whole of Africa. This plesiosaur swam in a shallow, tropical sea and the fossils are around 71.5 million years old.

Cardiocorax mukulu

The specimen was found in sandstone deposits, stratigraphically just 3 metres above where the holotype material for this taxon was found. The researchers who studied the fossils, which included Octávio Mateus (Museu da Lourinhã, Portugal) and lead author Miguel Marx from the Southern Methodist University (Dallas, Texas), concluded that the fossils represented C. mukulu as the overlapping skeletal material of this specimen – MGUAN PA278 with that of the holotype were virtually identical.

Picture credit: Everything Dinosaur

This elasmosaurid had been originally named and described back in 2015. The genus name comes from the Greek “kardia” which means heart and coracoid, a paired bone that forms part of the shoulder in most vertebrates. This is a reference to the unique heart-shaped fenestra (hole) which occurs between the coracoid bones, a characteristic that is unique to this genus. The specific or trivial name comes from the local Angolan Bantu dialect and means “ancestor).

High Resolution CT Scans Reveal Details of Plesiosaur Skull

The exquisite, three-dimensional preservation of the skull material provided the scientists with an opportunity to examine in close detail the morphology of the skull. The delicate fossil could have been damaged during further preparation, so the specimen was subjected to high resolution CT scans at the University of Texas High-Resolution X-ray CT Facility this permitted the anatomy of the skull to be revealed.

The holotype fossils, which were used to name and describe this elasmosaurid back in 2015 lacked skull bones. The discovery of an almost complete, three-dimensional skull of Cardiocorax enabled the research team to conduct an elaborate series of phylogenetic assessments to assess where within the Plesiosauria Cardiocorax should be placed.

Most of these analyses suggest an early-branching or intermediate position for Cardiocorax mukulu within the Elasmosauridae family. Elasmosaurines have elongated neck bones (cervical vertebrae), this anatomical characteristic is absent in Cardiocorax mukulu which suggests that it was a relic of an older, less derived lineage of elasmosaurids. These results indicate that several different types of elasmosaurid persisted into the Maastrichtian faunal stage of the Cretaceous.

The scientific paper: “The cranial anatomy and relationships of Cardiocorax mukulu (Plesiosauria: Elasmosauridae) from Bentiaba, Angola” by Miguel P. Marx, Octávio Mateus, Michael J. Polcyn, Anne S. Schulp, A. Olímpio Gonçalves and Louis L. Jacobs published in PLOS One.

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In 2017, Everything Dinosaur reported on the discovery of an extensive pterosaur nesting site that had been found south of the Tian Shan Mountains in Xinjiang (Xinjiang Uygur Autonomous Region), in north-western China. The bonebeds represented colonial nesting sites of Hamipterus tianshanensis. It was a flying reptile that had been formally named and described back in 2014.

To read Everything Dinosaur’s 2017 article about the Hamipterus nesting sites: Hamipterus Nesting Ground Discovery.

New Sauropods Described

Fieldwork in this area has revealed the presence of dinosaurs and a paper has been published this week describing sauropod fossils. These are the first dinosaurs to be identified from this part of China. Two of the fossil specimens have led to the erection of new sauropod species Silutitan sinensis and Hamititan xinjiangensis. Four incomplete bones from the sacrum along with associated sacral ribs representing another sauropod specimen have also been found, but as yet, no genus for these fossils has been assigned.

Silutitan sinensis

Described from a series of six articulated cervical vertebrae (neck bones), with associated cervical ribs, Silutitan sinensis (which translates as Chinese Silk Road Titan), has been assigned to the Euhelopodidae family and is thought to have been closely related to Euhelopus (E.zdanskyi). At an estimated twenty metres plus, it is the larger of the two sauropods to be described in the scientific paper.

Hamititan xinjiangensis

Although contemporaneous with Silutitan (Lower Cretaceous, Shengjinkou Formation of the Tugulu Group). Hamititan was not closely related. Cladistic analysis based on the tail bones (caudal vertebrae) from which this dinosaur was described, suggests that Hamititan is a titanosaur (a lithostrotian titanosaur), as such, it seems more closely related to South American titanosaurs such as Epachthosaurus and Notocolossus.

The genus name translates as Hami City Titan, whilst the species name honours the Xinjiang Uygur Autonomous Region of China.

A single theropod tooth (below, picture F), indicates the presence of theropod dinosaurs.

No Name for the Third Specimen

A third specimen consisting of four sacrum bones and associated sacral ribs has not been assigned to a species. However, the researchers, writing in the academic journal Scientific Reports conclude that not only do these fossils represent the first dinosaurs to be described from the Shengjinkou Formation but they also help to support the hypothesis that Asia was home to a great variety of different types of sauropod during the Early Cretaceous.

The scientific paper: “The first dinosaurs from the Early Cretaceous Hami Pterosaur Fauna, China” by Xiaolin Wang, Kamila L. N. Bandeira, Rui Qiu, Shunxing Jiang, Xin Cheng, Yingxia Ma and Alexander W. A. Kellner published in Scientific Reports.

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