| Mansourasaurus | |
|---|---|
 | |
| Restoration | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Clade: | †Lithostrotia |
| Genus: | †Mansourasaurus Sallamet al., 2018 |
| Type species | |
| Mansourasaurus shahinae Sallamet al., 2018 | |
Mansourasaurus ("Mansouralizard") is agenus ofherbivorouslithostrotiansauropoddinosaur from theQuseir Formation ofEgypt. Thetype and only species isMansourasaurus shahinae.
The discovery ofMansourasaurus was considered quite significant bypaleontologists, because very fewLate Cretaceous sauropod remains have been found in Africa, where the rockystrata that preserve remains elsewhere and produce rich fossil beds were typically not found exposed at or near ground level.
Hesham Sallam, a paleontologist atMansoura University, together with a team of students, discovered a sauropod skeleton in theDakhla Oasis in Egypt's Western Desert.[1] In 2016, it was reported that over thirty dinosaur specimens had been excavated, among them titanosaurian sauropods.[2]
Based on this skeleton, the type speciesMansourasaurus shahinae was named and described in January 2018 by Hesham M. Sallam, Eric Gorscak, Patrick M. O'Connor, Iman A. El-Dawoudi, Sanaa El-Sayed, Sara Saber, Mahmoud A. Kora, Joseph J. W. Sertich, Erik R. Seiffert, and Matthew C. Lamanna. The generic name refers to the Mansoura University. Thespecific name honours Mona Shahin, one of the founders of the Mansoura University Vertebrate Paleontology Center.[3]
TheMansourasaurusspecimen described in 2018 is itsholotype,MUVP 200, discovered in a layer of the Quseir Formation dating from the lateCampanian, about seventy-three million years old. It consists of a partial skeleton with skull and lower jaws.[3] It contains a fragment of the skull roof, a part of the lowerbraincase, the dentaries of the lower jaws, three neck vertebrae, two back vertebrae, eight ribs, the right scapula, the rightcoracoid, both humeri, a radius, a thirdmetacarpal, threemetatarsals, and parts ofosteoderms. The skeleton was found on a surface of four by three metres. It was not articulated. The authors concluded that the holotype is a juvenile specimen because the bones of its shoulder girdle had not yet fused. Anulna, specimen MUVP 201, found at twenty metres distance from the skeleton, was not referred to the species as it seemed somewhat too large for the holotype individual and a general connection to the species could not be proven.[3]
The not fully-grown holotype individual was about 8–10 metres (26–33 ft) long.[3] It probably weighed about 5,000 kg, approximately the same as abull African elephant.[4]
The describing authors indicated a number of distinguishing traits. These areautapomorphies, unique derived characters. Each lower jaw dentary bears ten teeth. Where the dentaries touch each other, at the front of the lower jaws, they possess a common "chin", equalling a third of the front height. The horizontal groove in the inner side of the dentary, thefossa Meckeliana, largely opens to below. The anterior middle neck vertebrae are pierced by aforamen in the rear side. In at least one anterior middle neck vertebra, the parapophysis, the process which bears the facet for the lower rib head, has a horizontal length equal to the vertebral centrum as a whole. With some anterior neck vertebrae, the bone web between the heads of the neck rib is pierced by a foramen. The lower end of the radius has a transverse width four times larger than the width measured from the front to the rear.[3]
Mansourasaurus was placed in theTitanosauria in a derived position as asister species ofLohuecotitan. Acladistic analysis showed it to belong to aclade of otherwise largely Eurasian sauropods, also includingAmpelosaurus,Lirainosaurus,Nemegtosaurus,Opisthocoelicaudia, andPaludititan, more or less contemporaneous forms. Hypotheses about relationships betweenLate Cretaceous African and Eurasian sauropods had been hard to test because very few of their remains had been found in Africa.Mansourasaurus represents the best-known continental African (i.e., excludingMadagascar) titanosaur of theUpper Cretaceous from the time period after theCenomanian. Its existence would show that the continent was far less isolated from the various Eurasian landmasses than had been assumed. The ancestors ofMansourasaurus would have reached Africa from Europe.[3]
