Showing posts with label Cretaceous. Show all posts
Showing posts with label Cretaceous. Show all posts

Saturday, February 24, 2018

Mansourasaurus shahinae - New Species of Titanosaur from Egypt

A New Titanosaur Species discovered in Egypt: Mansourasaurus shahinae.


Mansourasaurus shahinae, was a type of titanosaur-sauropod (long-necked plant-eating) dinosaurs which roamed Earth around 80 million years ago during Cretaceous period. 

Prominent hypotheses advanced over the past two decades have sought to characterize the Late Cretaceous continental vertebrate palaeobiogeography of Gondwanan landmasses, but have proved difficult to test because terrestrial vertebrates from the final ~30 million years of the Mesozoic are extremely rare and fragmentary on continental Africa (including the then-conjoined Arabian Peninsula but excluding the island of Madagascar). Here we describe a new titanosaurian sauropod dinosaur, Mansourasaurus shahinae gen. et sp. nov., from the Upper Cretaceous (Campanian) Quseir Formation of the Dakhla Oasis of the Egyptian Western Desert. Represented by an associated partial skeleton that includes cranial elements, Mansourasaurus is the most completely preserved land-living vertebrate from the post-Cenomanian Cretaceous (~94–66 million years ago) of the African continent. Phylogenetic analyses demonstrate that Mansourasaurus is nested within a clade of penecontemporaneous titanosaurians from southern Europe and eastern Asia, thereby providing the first unambiguous evidence for a post-Cenomanian Cretaceous continental vertebrate clade that inhabited both Africa and Europe. The close relationship of Mansourasaurus to coeval Eurasian titanosaurians indicates that terrestrial vertebrate dispersal occurred between Eurasia and northern Africa after the tectonic separation of the latter from South America ~100 million years ago. These findings counter hypotheses that dinosaur faunas of the African mainland were completely isolated during the post-Cenomanian Cretaceous.

Image credit: Andrew McAfee, Carnegie Museum of Natural History
Ref & abstract credit : https://www.nature.com/articles/s41559-017-0455-5

Saturday, February 18, 2017

Hatzegopteryx where top predators of Cretaceous Romania


A new study of neck biomechanics in Neck biomechanics indicate that giant Transylvanian azhdarchid pterosaurs were short-necked arch predators. 


Azhdarchid pterosaurs include the largest animals to ever take to the skies with some species exceeding 10 metres in wingspan and 220 kg in mass. Associated skeletons show that azhdarchids were long-necked, long-jawed predators that combined a wing planform suited for soaring with limb adaptations indicative of quadrupedal terrestrial foraging. The postcranial proportions of the group have been regarded as uniform overall, irrespective of their overall size, notwithstanding suggestions that minor variation may have been present.

Like all azhdarchid pterosaurs, Hatzegopteryx was probably a terrestrially foraging generalist predator. It is significantly larger than any other terrestrial predator from Maastrichtian Europe; due to its large size in an environment otherwise dominated by island dwarf dinosaurs, with no large hypercarnivorous theropods in the region, it has been suggested that Hatzegopteryx played the role of an apex predator in the Haţeg Island ecosystem. The robust anatomy of Hatzegopteryx suggests that it may have tackled larger prey than other azhdarchids, including animals too large to swallow whole; similarly, some modern storks (particularly the marabou stork and the jabiru) are known to attack and kill large prey such as flamingoes, and occasionally children, with their beaks. Meanwhile, other giant azhdarchids like Arambourgiania would probably have instead fed on small prey (up to the size of a human), including hatchling or small dinosaurs and eggs. Another pterosaur, Thalassodromeus, has similarly been suggested to be raptorial.

Credit: 
*https://peerj.com/articles/2908/
*en.wikipedia.com 
*image - Mark Witton