[Paleontology • 2017] Neck Biomechanics indicate that Giant Transylvanian Azhdarchid Pterosaurs, Hatzegopteryx sp., were Short-necked Arch Predators

 Transylvanian giant azhdarchid pterosaur Hatzegopteryx sp. preys on the rhabdodontid iguanodontian Zalmoxes. Because large predatory theropods are unknown on Late Cretaceous Haţeg Island, giant azhdarchids may have played a key role as terrestrial predators in this community. 

DOI:   10.7717/peerj.2908 

Abstract

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. Here, we discuss a recently discovered giant azhdarchid neck vertebra referable to Hatzegopteryx from the Maastrichtian Sebeş Formation of the Transylvanian Basin, Romania, which shows how some azhdarchids departed markedly from conventional views on their proportions. This vertebra, which we consider a cervical VII, is 240 mm long as preserved and almost as wide. Among azhdarchid cervicals, it is remarkable for the thickness of its cortex (4–6 mm along its ventral wall) and robust proportions. By comparing its dimensions to other giant azhdarchid cervicals and to the more completely known necks of smaller taxa, we argue that Hatzegopteryx had a proportionally short, stocky neck highly resistant to torsion and compression. This specimen is one of several hinting at greater disparity within Azhdarchidae than previously considered, but is the first to demonstrate such proportional differences within giant taxa. On the assumption that other aspects of Hatzegopteryx functional anatomy were similar to those of other azhdarchids, and with reference to the absence of large terrestrial predators in the Maastrichtian of Transylvania, we suggest that this pterosaur played a dominant predatory role among the unusual palaeofauna of ancient Haţeg.

Figure 9: Diversity in predicted life appearance and ecologies for giant azhdarchid pterosaurs.

(A) two giant, long-necked azhdarchids—the Maastrichtian species Arambourgiania philadelphiae—argue over a small theropod;
(B) the similarly sized but more powerful Maastrichtian, Transylvanian giant azhdarchid pterosaur Hatzegopteryx sp. preys on the rhabdodontid iguanodontian Zalmoxes. Because large predatory theropods are unknown on Late Cretaceous Haţeg Island, giant azhdarchids may have played a key role as terrestrial predators in this community. 

Darren Naish​​ and Mark P. Witton​. 2017. Neck Biomechanics indicate that Giant Transylvanian Azhdarchid Pterosaurs were Short-necked Arch Predators.
   PeerJ. 5:e2908. DOI:   10.7717/peerj.2908

  

[Paleontology • 2013] Malawania anachronus • A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs | Fossil saved from mule track revolutionizes understanding of ancient dolphin-like marine reptile

Malawania anachronus,
the Jurassic-style Cretaceous ichthyosaur from Iraq.

Illustrations by Robert Nicholls, paleocreations.com;
coloring by C. M. Kosemen, cmkosemen.com

Abstract

Cretaceous ichthyosaurs have typically been considered a small, homogeneous assemblage sharing a common Late Jurassic ancestor. Their low diversity and disparity have been interpreted as indicative of a decline leading to their Cenomanian extinction. We describe the first post-Triassic ichthyosaur from the Middle East, Malawania anachronus gen. et sp. nov. from the Early Cretaceous of Iraq, and re-evaluate the evolutionary history of parvipelvian ichthyosaurs via phylogenetic and cladogenesis rate analyses. Malawania represents a basal grade in thunnosaurian evolution that arose during a major Late Triassic radiation event and was previously thought to have gone extinct during the Early Jurassic. Its pectoral morphology appears surprisingly archaic, retaining a forefin architecture similar to that of its Early Jurassic relatives. After the initial latest Triassic radiation of early thunnosaurians, two subsequent large radiations produced lineages with Cretaceous representatives, but the radiation events themselves are pre-Cretaceous. Cretaceous ichthyosaurs therefore include distantly related lineages, with contrasting evolutionary histories, and appear more diverse and disparate than previously supposed.

Keywords: Parvipelvia, Baracromia, Malawania anachronus, Early Cretaceous

Figure 1. Holotype specimen of Malawania anachronus gen. et sp. nov., NHMUK PV R6682.

Fossil saved from mule track revolutionizes understanding of ancient dolphin-like marine reptile

| An international team of scientists have revealed a new species of ichthyosaur (a dolphin-like marine reptile from the age of dinosaurs) from Iraq, which revolutionises our understanding of the evolution and extinction of these ancient marine reptiles.

: http://phys.org/news/2013-05-fossil-mule-track-revolutionizes-ancient.html 

Fischer V, Appleby RM, Naish D, Liston J, Riding JB, Brindley S and Godefroit P. 2013. A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs. Biology Letters, 9: 20130021. DOI: 10.1098/rsbl.2013.0021

[Paleontology • 2013] Eurazhdarcho langendorfensis • A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution

Abstract

We describe a new taxon of medium-sized (wing span ca. 3 m) azhdarchid pterosaur from the Upper Cretaceous Transylvanian Basin (Sebeş Formation) of Romania. This specimen is the most complete European azhdarchid yet reported, comprising a partially articulated series of vertebrae and associated forelimb bones. The new taxon is most similar to the Central Asian Azhdarcho lancicollis Nessov but possesses a suite of autapomorphies in its vertebrae that include the relative proportions of cervicals three and four and the presence of elongated prezygapophyseal pedicles. The new taxon is interesting in that it lived contemporaneously with gigantic forms, comparable in size to the famous Romanian Hatzegopteryx thambema. The presence of two distinct azhdarchid size classes in a continental depositional environment further strengthens suggestions that these pterosaurs were strongly linked to terrestrial floodplain and wooded environments. To support this discussion, we outline the geological context and taphonomy of our new specimen and place it in context with other known records for this widespread and important Late Cretaceous pterosaurian lineage.

Map to show the global distribution of faunas containing small-medium and giant-sized azhdarchids, evidence for niche partioning.
doi:10.1371/journal.pone.0054268

Paleontologists Identify New Species of Pterosaur | Eurazhdarcho 

http://www.sci-news.com/paleontology/article00867.html

68-million-year-old fossil, named Eurazhdarcho langendorfensis, were collected from the Late Cretaceous rocks of Sebeş-Glod in the Transylvanian Basin, Romania.

“Eurazhdarcho belong to a group of pterosaurs called the azhdarchids. These were long-necked, long-beaked pterosaurs whose wings were strongly adapted for a soaring lifestyle. Several features of their wing and hind limb bones show that they could fold their wings up and walk on all fours when needed,” said Dr Darren Naish of the University of Southampton, who helped identify the new species and co-author a paper in the journal PLoS ONE.

“With a three-meter wingspan, Eurazhdarcho would have been large, but not gigantic. This is true of many of the animals so far discovered in Romania; they were often unusually small compared to their relatives elsewhere.”

The discovery is the most complete example of an azhdarchid found in Europe so far, and its discovery supports a long-argued theory about the behavior of these types of creatures.

“Experts have argued for years over the lifestyle and behavior of azhdarchids. It has been suggested that they grabbed prey from the water while in flight, that they patrolled wetlands and hunted in a heron or stork-like fashion, or that they were like gigantic sandpipers, hunting by pushing their long bills into mud,” explained senior author Dr Gareth Dyke of the National Oceanography Center Southampton.

“One of the newest ideas is that azhdarchids walked through forests, plains and other places in search of small animal prey. Eurazhdarcho supports this view of azhdarchids, since these fossils come from an inland, continental environment where there were forests and plains as well as large, meandering rivers and swampy regions.”

Fossils from the region show that there were several places where both giant azhdarchids and small azhdarchids lived side by side. Eurazhdarcho's discovery indicates that there were many different animals hunting different prey in the region at the same time, demonstrating a much more complicated picture of the Late Cretaceous world than first thought.

Vremir, M. T. S.; Kellner, A. W. A.; Naish, D.; Dyke, G. J. 2013. A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution. PLoS ONE. 8: e54268. doi:10.1371/journal.pone.0054268